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Model‐oriented naming therapy: Testing predictions of a connectionist model

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Aphasiology
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Abstract

Background: The two versions of the connectionist model of Dell and colleagues offer alternative explanations of aphasic naming disorders (Dell, Schwartz, Martin, Saffran, & Gagnon, 1997 Dell, G. S., Schwartz, M. F., Martin, N., Saffran, E. M. and Gagnon, D. A. 1997. Lexical access in aphasic and nonaphasic speakers.. Psychological Review, 104: 801–838. [CrossRef], [PubMed], [Web of Science ®] [Google Scholar]; Foygel & Dell, 2000 Foygel, D. and Dell, G. S. 2000. Models of impaired lexical access in speech production.. Journal of Memory and Language, 43: 182–216. [CrossRef], [Web of Science ®], [CSA] [Google Scholar]). The semantic‐phonological (SP) model hypothesises impairments in lexical‐semantic or lexical‐phonological connections, and the weight‐decay (WD) model assumes global impairments in either connection weights or activation decay. In each version, a patient's error pattern in picture naming is simulated to assess the underlying disorder (connectionist “diagnosis”). A systematic comparison of both model versions in model‐oriented naming therapy has not yet been performed. Moreover, if the normalisation of the error pattern during recovery is lesion‐specific, as suggested in the SP model (Schwartz, Dell, Martin, Gahl, & Sobel, 2006 Schwartz, M. F., Dell, G. S., Martin, N., Gahl, S. and Sobel, P. 2006. A case‐series test of the interactive two‐step model of lexical access: Evidence from picture naming.. Journal of Memory and Language, 54: 223–264. [Google Scholar]), this should be observable in the patient data. Aims: Predictions were made and tested regarding the relation between (1) connectionist diagnosis and therapy outcome, and (2) connectionist diagnosis and error pattern development. For example, patients with phonological disorders in the SP model should (1) benefit more from phonological as compared to semantic therapy, and (2) present a decrease of nonwords in their naming responses. Methods & Procedures: The connectionist diagnosis and a 4‐week therapy with cueing hierarchies (Howard, 2000 Howard, D. 2000. “Cognitive neuropsychology and aphasia therapy: The case of word retrieval.”. In Acquired neurogenic communication disorders: A clinical perspective, Edited by: Papathanasiou, I. London: Whurr. [Google Scholar]; Wambaugh et al., 2001 Wambaugh, J. L., Linebaugh, C. W., Doyle, P. J., Martinez, A. L., Kalinyak‐Fliszar, M. and Spencer, K. A. 2001. Effects of two cueing treatments on lexical retrieval in aphasic speakers with different levels of deficit.. Aphasiology, 15: 933–950. [Taylor & Francis Online], [Web of Science ®], [CSA] [Google Scholar]) were administered to 10 German‐speaking aphasic patients with naming disorders. Six patients, who had been diagnosed by the SP model, received semantic and phonological therapy. The other four patients, diagnosed by the WD model, received increasing and vanishing therapy (Abel, Schultz, Radermacher, Willmes, & Huber, 2005 Abel, S., Schultz, A., Radermacher, I., Willmes, K. and Huber, W. 2005. Decreasing and increasing cues in naming therapy.. Aphasiology, 19: 831–848. [Taylor & Francis Online], [Web of Science ®] [Google Scholar]). Outcomes & Results: Cueing therapy was generally effective for 9 of 10 patients. The trend of improvement was always found in the direction predicted by the connectionist diagnosis, except for two patients diagnosed by the SP model who presented a numerical trend in the opposite direction. Nevertheless, the SP model offered a more plausible explanation of lesion‐specific therapy outcomes, and it properly predicted the error pattern development. Moreover, the errorless learning procedure applied in vanishing therapy was favourable for patients with phonological (SP model) or weight (WD model) lesions, and this may be attributed to their characteristic error types and an impairment of editorial processes. Conclusions: Models can be informative about the effectiveness of potential therapies and error pattern developments. Data from therapy studies can test competing models.

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... Researchers proposed that memory impairments limited the ability to filter out incorrect responses. Likewise, errorless learning has been utilized within picture naming tasks to treat anomia in acquired aphasia resulting in gains for PWA that are broadly similar or less than the gains from errorful anomia therapy (see below for an explanation on errorful learning; Abel et al., 2005Abel et al., , 2007Choe et al., 2017;Conroy et al., 2009aConroy et al., , 2009bFillingham et al., 2003;Fillingham et al., , 2006Lacey, 2010;Lacey et al., 2004;Thomas et al., 2012;Mckissock & Ward, 2007;Middleton et al., 2015Middleton et al., , 2016Middleton et al., , 2019Schuchard & Middleton, 2018a, 2018b. In an errorless picture naming task, a person with aphasia is presented with the spoken and written target name along with the stimulus picture and typically asked to immediately repeat the name, sometimes with fading cues. ...
... The gating mechanism consists of three components: 1) detection of errant behavior, 2) memory/coding of responses and stimuli, and 3) attentional-executive skills for halting learning when errors occur or correcting errors (Lambon- . When comparing errorless to errorful training in anomia therapy, outcomes generally show no difference (Abel et al., 2007;Choe et al., 2017;Conroy et al., 2009a;Fillingham et al., , 2006Lacey, 2010;Lacey et al., 2004). Some studies have reported an advantage of errorful instruction in specific analyses or participants (Abel et al., 2005;Lacey et al., 2004), while other studies have found an advantage for errorless instruction in certain analyses (Conroy et al., 2009b;Mckissock & Ward, 2007). ...
... sometimes equated with learning (see Peñaloza et al., 2022). Studies are emerging that examine the impact of different methods of instruction on rehabilitation outcomes for people with aphasia (Abel et al., 2005(Abel et al., , 2007Choe et al., 2017;Conroy et al., 2009aConroy et al., , 2009bFillingham et al., , 2006Fridriksson et al., 2005;Friedman et al., 2017;Lacey, 2010;Lacey et al., 2004;Mckissock & Ward, 2007;Middleton et al., 2015Middleton et al., , 2016Middleton et al., , 2019Schuchard & Middleton, 2018a, 2018b or examine the relationship between novel learning and outcomes (Dignam et al., 2016;Laganaro et al., 2006;Schuchard et al., 2017;Tuomiranta et al., 2014). However the body of work examining these questions is limited, and systematic methods to identify specific learning deficits in people with aphasia do not exist (Helm-Estabrooks, 2002;Peñaloza et al., 2022). ...
Article
Background: While linguistic deficits are key to diagnosing and treating aphasia, there is growing interest in the cognitive processes important for rehabilitation outcomes, particularly the role of learning. Of relevance to the current study, research has manipulated instructional methods (errorless vs. errorful) to assess their effects on outcomes. However, it is still unclear whether individualized profiles of errorless and errorful learning exist in aphasia and whether they might be meaningful for clinical practice. Aims: The current study aimed to examine learning in people with aphasia, manipulating instruction method (errorless, errorful) and linguistic demands of learning. Methods & procedures: Nine people with stroke-induced aphasia participated in this preliminary study. Participants engaged in error-less and errorful novel object pairing and word retrieval tasks. Learning outcomes were assessed on the same day, next day, and after one week. Participants also completed cognitive-linguistic assessments to investigate the contribution of memory, language, and executive functioning abilities on learning outcomes. Outcomes & results: At the group level, participants performed significantly better following errorful training for novel object pair-ing (p = 0.001) relative to errorless training. An errorful advantage was observed at the individual level in 7 participants during same day testing, with the highest overall performers on the task showing the most persistent errorful learning benefits. In the word retrieval practice task, group and individual-level differences in scores following errorless and errorful practice were minimal. Scores in errorful novel object pair learning correlated with verbal short-term memory and nonverbal long-term memory assessments, while no other correlations were found between learning scores and cognitive-linguistic variables. Conclusions: Findings are consistent with prior research that suggests that successful effortful retrieval may pose an advantage over errorless learning when acquiring novel information and the potential contributions of verbal short-term memory and nonverbal long term memory on learning. Results from the word retrieval practice task draw attention to differences between practicing lexical access
... One study (Thomas et al., 2012) was removed from the comparative effectiveness data extraction because the participant produced more errors during ELess compared to EFul training. Twelve studies compared ELess and EFul (Abel et al., 2005(Abel et al., , 2007Choe et al., 2017;Conroy et al., 2009aConroy et al., , 2009bFillingham et al., 2005aFillingham et al., , 2005bFillingham et al., , 2006Lacey, 2010;Lacey et al., 2004;McKissock & Ward, 2007;Thomas et al., 2012), six studies compared ELess and RP (Friedman et al., 2017;Middleton et al., 2019Middleton et al., , 2015Middleton et al., , 2016Schuchard & Middleton, 2018a, 2018b), and one study compared RP and EFul (Fridriksson et al., 2005; see Figure 2). ...
... Models of lexical access have been applied to explain learning under ELess naming treatment in five studies (Abel et al., 2005(Abel et al., , 2007Middleton et al., 2019;Schuchard & Middleton, 2018a, 2018b. Abel et al. (2005Abel et al. ( , 2007 applied the weight decay model of lexical access (see Dell et al., 1997) to ELess and EFul. ...
... Models of lexical access have been applied to explain learning under ELess naming treatment in five studies (Abel et al., 2005(Abel et al., , 2007Middleton et al., 2019;Schuchard & Middleton, 2018a, 2018b. Abel et al. (2005Abel et al. ( , 2007 applied the weight decay model of lexical access (see Dell et al., 1997) to ELess and EFul. However, they found that a semantic-phonological model of lexical access better aligned with treatment response. ...
Article
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Purpose Increasingly, mechanisms of learning are being considered during aphasia rehabilitation. Well-characterized learning mechanisms can inform “how” interventions should be administered to maximize the acquisition and retention of treatment gains. This systematic scoping review mapped hypothesized mechanisms of action (MoAs) and treatment ingredients in three learning-based approaches targeting naming in aphasia: errorless learning (ELess), errorful learning (EFul), and retrieval practice (RP). The rehabilitation treatment specification system was leveraged to describe available literature and identify knowledge gaps within a unified framework. Method PubMed and CINHAL were searched for studies that compared ELess, EFul, and/or RP for naming in aphasia. Independent reviewers extracted data on proposed MoAs, treatment ingredients, and outcomes. Results Twelve studies compared ELess and EFul, six studies compared ELess and RP, and one study compared RP and EFul. Hebbian learning, gated Hebbian learning, effortful retrieval, and models of incremental learning via lexical access were proposed as MoAs. To maximize treatment outcomes within theorized MoAs, researchers manipulated study ingredients including cues, scheduling, and feedback. Outcomes in comparative effectiveness studies were examined to identify ingredients that may influence learning. Individual-level variables, such as cognitive and linguistic abilities, may affect treatment response; however, findings were inconsistent across studies. Conclusions Significant knowledge gaps were identified and include (a) which MoAs operate during ELess, EFul, and RP; (b) which ingredients are active and engage specific MoAs; and (c) how individual-level variables may drive treatment administration. Theory-driven research can support or refute MoAs and active ingredients enabling clinicians to modify treatments within theoretical frameworks.
... In a picture-naming task, for example, cues are given if the subject provides an incorrect name or is unable to answer. A phonological cue often involves the oral presentation of the first sound of a target word (e.g., "b" for "bag; Abel et al., 2007). A semantic cue, on the other hand, typically involves an orally presented explanatory phrase like "there may be flowers in" for the target word "garden" (Abel et al., 2007). ...
... A phonological cue often involves the oral presentation of the first sound of a target word (e.g., "b" for "bag; Abel et al., 2007). A semantic cue, on the other hand, typically involves an orally presented explanatory phrase like "there may be flowers in" for the target word "garden" (Abel et al., 2007). Upon presentation of these cues, semantic or phonological neighbors (or semantically or phonologically related features) are activated, which provides a further impulse within the word production process and can thus facilitate word production and correct naming (Nickels and Best, 1996;Brackenbury and Pye, 2005;Gershkoff-Stowe and Hahn, 2007;Velez and Schwartz, 2010;phonological cues: German, 2002). ...
... If cues are ineffective, it is an indication that certain mental representations are lost or have not yet been acquired (McGregor and Appel, 2002;Gray, 2005;Alt and Plante, 2006). If cues are effective, it is an indication that the mental representations have momentarily been disrupted due to an access disorder of some kind (Gershkoff-Stowe and Smith, 1997;Abel et al., 2007). ...
Article
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Background To produce and understand words, humans access the mental lexicon. From a functional perspective, the long-term memory component of the mental lexicon is comprised of three levels: the concept level, the lemma level, and the phonological level. At each level, different kinds of word information are stored. Semantic as well as phonological cues can help to facilitate word access during a naming task, especially when neural dysfunctions are present. The processing corresponding to word access occurs in specific parts of working memory. Neural models for simulating speech processing help to uncover the complex relationships that exist between neural dysfunctions and corresponding behavioral patterns. Methods The Neural Engineering Framework (NEF) and the Semantic Pointer Architecture (SPA) are used to develop a quantitative neural model of the mental lexicon and its access during speech processing. By simulating a picture-naming task (WWT 6-10), the influence of cues is investigated by introducing neural dysfunctions within the neural model at different levels of the mental lexicon. Results First, the neural model is able to simulate the test behavior for normal children that exhibit no lexical dysfunction. Second, the model shows worse results in test performance as larger degrees of dysfunction are introduced. Third, if the severity of dysfunction is not too high, phonological and semantic cues are observed to lead to an increase in the number of correctly named words. Phonological cues are observed to be more effective than semantic cues. Conclusion Our simulation results are in line with human experimental data. Specifically, phonological cues seem not only to activate phonologically similar items within the phonological level. Moreover, phonological cues support higher-level processing during access of the mental lexicon. Thus, the neural model introduced in this paper offers a promising approach to modeling the mental lexicon, and to incorporating the mental lexicon into a complex model of language processing.
... The computer-assisted assessment of impairment type in a model-oriented framework, as featured by the interactive and connectionist lexical model of Dell (Foygel & Dell, 2000), provides an easy to use, automated, and objective classification of the disorder as semantic (S) or phonological (P) (Abel, Huber, & Dell, 2009b). An application of parallelised cueing-hierarchies, a wellknown and effective stimulation technique, is optimal for a comparison of therapy methods guided by impairment type (e.g., Abel, Willmes, & Huber, 2007;Abel, Schultz, Radermacher, Willmes, & Huber, 2003). In this approach, cues with increasing semantic or phonological information about the target word are delivered and assist the patient's attempts to name depicted objects short-term and improve word finding long-term. ...
... Semantic cueing-hierarchies for SEM consisted of a superordinate, a definition, a closure sentence, and auditory target comprehension. Phonological cueinghierarchies for PHO comprised the number of syllables, the onset, the first syllable, and overt repetition of the target (see also Abel et al., 2007, for a similar therapy approach). ...
... Patients were asked to name each picture consecutively presented in a paper/pencil version. If the patient failed to produce the correct response, he/she was given increasing assistance according to the semantic or phonological cueing-hierarchy (see Abel et al., 2007, for a similar procedure). ...
Article
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Model-oriented therapies of aphasic word production have been shown to be effective, with item-specific therapy effects being larger than generalisation effects for untrained items. However, it remains unclear whether semantic versus phonological therapy lead to differential effects, depending on type of lexical impairment. Functional imaging studies revealed that mainly left-hemisphere, perisylvian brain areas were involved in successful therapy-induced recovery of aphasic word production. However, the neural underpinnings for model-oriented therapy effects have not received much attention yet.
... In the present study we intend to directly compare the efficacy of semantic and phonological cueing hierarchies in a patient with SD. The cueing hierarchies have already been proven to be successful in aphasia therapy after stroke (Abel, Willmes, & Huber, 2007). ...
... To summarise, the purpose of the present study was to investigate whether the cueing hierarchies as established for naming therapy in aphasia (Abel et al., 2007) were 4 DRESSEL ET AL. also effective in a patient with SD, and whether there is a systematic effect of training on cortical activity. More specifically, we were interested in whether signal changes occur in, or close to, atrophic regions due to the functioning of residual neurons, or whether training induced improvements are associated with the recruitment of right hemispheric areas. ...
... Errors were coded as semantic, phonological, both semantic and phonological (mixed), unrelated, nonword, or omission. The error pattern of pre-and post-tests was fitted in the semantic-phonological model of Dell (SP model;Foygel & Dell, 2000) using the Internet programme Webfit to indicate a cognitive phonological lesion or a cognitive semantic lesion, respectively (further details and data for German participants are provided in Abel et al., 2007). ...
Article
Background: Studies on anomia treatment in semantic dementia demonstrate that re-learning is possible, but maintenance and generalisation of improvements are limited. Changes in cortical activation associated with anomia treatment have already been demonstrated in aphasic patients after stroke. Recovery of brain functions under the impact of deficit-specific treatment in semantic dementia has not been explored yet. Nevertheless, recent activation studies using language tasks in patients with neurodegenerative diseases report altered activation patterns, involving diverse brain regions ipsi- or contralateral to the primarily affected left hemisphere.Aims: The purpose of the present study was to investigate if phonological and semantic cueing hierarchies established for naming therapy in aphasia were also effective in a patient with semantic dementia. Moreover, we aimed to examine changes of brain activity associated with anomia treatment.Methods & Procedures: One individual with semantic dementia participated in the present study. Over a period of 4 weeks the participant received an intensive model-oriented treatment with phonological and semantic cueing hierarchies. Two pre-tests and two post-tests (one immediately after training and one 2 months later) were administered. The second pre-test and both follow-ups were registered inside the scanner.Outcomes & Results: Behaviourally, both treatments resulted in specific training effects, which subsequently decreased over time. Concerning functional magnetic resonance imaging data, improved naming following therapy was mirrored by changes in cortical activity, predominantly located in right superior and inferior temporal gyrus.Conclusions: Cueing hierarchies were successful, resulting in specific and immediate treatment effects, corroborating previous treatment studies in semantic dementia. Treatment-induced changes in cortical activity were mainly concentrated in right temporal cortex. Since right-sided modulation of cortical activity was associated with training-induced improvements in task performance, it may reflect right hemispheric compensatory mechanisms in this participant.
... More recently, Abel, Wilmes & Huber (2007) designed a treatment for word retrieval impairments based directly on the hypothesis that some impairments stem from reduced connection strength and others from increased decay rate (the processing parameters in Dell's interactive activation model discussed earlier). The treatment involved use of two types of cueing hierarchies, the increasing (or ascending) cue method and the vanishing (descending) cue method. ...
... The treatment involved use of two types of cueing hierarchies, the increasing (or ascending) cue method and the vanishing (descending) cue method. Abel et al.'s (2007) predictions were confirmed by the results of treatment. These two treatment studies are good examples of the potential for two-way traffic between theory and treatment work: not only can models guide therapeutic attempts, but therapy results can also be used to set models to test. ...
... Additionally, boxes-and-arrows models are not capable of accounting for either the dynamics of changes in language patterns that occur with recovery of language function without treatment intervention, or the dynamics of re-learning during treatment. These needs are beginning to be addressed as is evidenced by some applications of connectionist models to the development of treatments for aphasia (Abel et al., 2007) and studies of language changes over the course of recovery (Martin et al., 1996) and it is highly likely that these studies represent the beginning of a new path for CNP as it is applied to aphasia rehabilitation. ...
Article
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BACKGROUND: In recent years, some critical voices have been raised in regard to the significance of cognitive neuropsychology (CNP) to the study of brain and mind. Given the central role of language disorders in CNP research, it is time to consider the relevance of this research approach in aphasiology. AIMS: We analyze the main points of criticism raised against the CNP research approach, evaluate the significance of this approach to the study of acquired language disorders, and make some suggestions concerning further development of the field. MAIN CONTRIBUTION: The main points of criticism against CNP (reliance on single-case studies; single-minded hunt for dissociations; emptiness of theorizing) have been important long-term concerns but do not take into account the fact that during its history of circa four decades, the CNP approach has diversified. There are thus CNP studies that rely on case series analyses, focus on error analyses rather than mere dissociations, or employ computational modeling rather than the "boxes-and-arrows" models of the mental architecture. The CNP approach to cognition and its disorders is thus applicable to different research questions and theoretical stances, providing experimental rigor to single-case patient studies. With regard to clinical applications in aphasia diagnostics and treatment, the CNP approach provides a richer view on the strengths and weaknesses of a patient's cognitive-linguistic abilities. CONCLUSIONS: We believe that CNP case studies continue to be an important source of information for generating hypotheses and providing converging evidence for research on the mind and on the brain. There is however a need for further research development especially in computational modeling of language processes, their impairments, and recovery. This research is expected to provide further benefit to clinical diagnostics and treatment of aphasia.
... A widely accepted practice is to target treatment towards the underlying impairment (Whitworth et al., 2014). For example, under this approach, a wordfinding difficulty as a result of semantic impairment would be treated with semantic therapy, while a word-finding difficulty resulting from a phonological impairment would be treated with phonological therapy (e.g., Abel et al., 2007;Nettleton & Lesser, 1991). However, there are results that suggest that this one-to-one relationship does not necessarily guarantee success (e.g., Best & Nickels, 2000;Kristinsson et al., 2021), and it is clear that there remains a need to further examine the relationship between language impairment, the processing requirements of particular therapy approaches, and treatment outcomes. ...
... Given that in Goodglass et al. (1997) seminal study, initial phoneme cues were the most successful (compared to semantic cues, also see Meteyard & Bose, 2018), it is surprising that not all studies included these cues. Studies have also explored the effects of changing the order of cues: that is, increasing informativeness of the cue (more information provided by the cue as the hierarchy progresses) versus decreasing informativeness (e.g., Abel et al., 2015Abel et al., , 2007, 2009c or random cue orders (Diedrichs et al., 2023). However, there is no conclusive evidence that one order produces better outcomes than another. ...
... The last studies we discuss are those that aimed to use behavioral therapy to target language improvements via neural reorganization. These studies are by Abel 16,17 and Wilson 18 and colleagues. For both studies, treatment ingredients are behavioral speech and language therapies, and targets are language behaviors supported by specific neural processes. ...
... If a patient failed to name an item correctly, they were given increasing assistance according to semantic and phonological cueing hierarchy as follows: the semantic cueing hierarchy consisted of a superordinate, a definition, a closure sentence, and auditory target comprehension, while the phonological hierarchy consisted of tapping the syllable number, the phoneme onset, the first syllable, and overt target repetition. Details of the treatment can be found in the article by Abel et al. 17 All of these were predicted to target improved semantic and phonological representations. ...
Article
The Rehabilitation Treatment Specification System (RTSS; Van Stan et al., 2019) was developed as a systematic way to describe rehabilitation treatments for the purpose of both research and practice. The RTSS groups treatments by type and describes them by three elements - the treatment (i) ingredients and (ii) the mechanisms of action that yield changes in the (iii) target behavior. Adopting the RTSS has the potential to improve consistency in research, allowing for better cross-study comparisons to strengthen the body of research supporting various treatments. As it is still early in its development, the RTSS has not yet been widely implemented across different rehabilitation disciplines. In particular, aphasia recovery is one area of rehabilitation that could benefit from a unifying framework. Accordingly, this paper is part of a series where we illustrate how the RTSS can be applied to aphasia treatment and research. This paper more specifically focuses on examining the neurobiological mechanisms of action associated with experimental aphasia therapies – including brain stimulation and pharmacological intervention – as well as more traditional behavioral therapy. Key elements of the RTSS are described, and four example studies are used to illustrate how the RTSS can be implemented. The benefits of a unifying framework for the future of aphasia treatment research and practice are discussed.
... Cognition, as defined by Coltheart in 2001 [11], represents the study of cognitive processes through data from people who suffer from either developmental or acquired disorders of cognition. From a somatic point of view, this definition is challenged by the dichotomy between neuroanatomy and physiology, taking into account localizationist (Broca, 1861) [12] and connectionist (Abel, 2007) models [13]. Furthermore, the implications of neurological impairments depend on the patient's profession, daily activities, and lesion laterality and location. ...
... Cognition, as defined by Coltheart in 2001 [11], represents the study of cognitive processes through data from people who suffer from either developmental or acquired disorders of cognition. From a somatic point of view, this definition is challenged by the dichotomy between neuroanatomy and physiology, taking into account localizationist (Broca, 1861) [12] and connectionist (Abel, 2007) models [13]. Furthermore, the implications of neurological impairments depend on the patient's profession, daily activities, and lesion laterality and location. ...
Article
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Clinical outcomes after surgery for intracranial meningiomas might be overvalued as cognitive dimensions and quality of life are probably underreported. This review aims to summarize the current state of cognitive screening and treatment-related outcomes after meningioma surgery. We present a systematic review (Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA-P) 2015-based) of cognitive outcomes after intracranial meningioma surgery. A total of 1572 patients (range 9–261) with a mean age of 58.4 years (range 23–87), and predominantly female (n = 1084, 68.9%) were identified. Mean follow-up time after treatment was 0.86 � 0.3 years. Neuropsychological assessment was very heterogeneous, but five dimensions of cognition were described: memory (19/22); attention (18/22); executive functions (17/22); language (11/22); flexibility (11/22 studies). Cognitive abilities were impaired in 18 studies (81.8%), but only 1 showed deterioration in all dimensions simultaneously. Memory was the most affected, with significant post-therapy impairment in 9 studies (40.9%). Postoperatively, only 4 studies (18.2%) showed improvement in at least one dimension. Meningioma patients had significantly lower cognitive scores when compared to healthy subjects. Surgery and radiotherapy for meningiomas were associated with cognitive impairment, probably followed by a partial recovery. Cognition is poorly defined, and the assessment tools employed lack standardization. Cognitive impairment is probably underreported in meningioma patients.
... Thus, we aimed to apply lexical therapy, which was shown to be effective in a previous study (Abel et al., 2007), to a group of 14 patients with aphasic word retrieval deficits after left-hemisphere stroke. We intended to illuminate brain reorganization considering functional MRI time-series of (I-a) recovered word production before therapy in a picture naming task; (I-b) recovery induced by therapy, as well as aphasic brain activations in comparison to initial (II-a); and (II-b) repeated naming in healthy controls. ...
... An influence of the applied cueing-therapy method, which is known to feature word priming (Abel et al., 2007) instead of (re-)learning of linguistic rules or compensatory strategies, remains to be investigated. Moreover, we cannot reveal the impact of treatment-induced changes over and above repeated exposure to the stimuli, as our control group did not receive multiple stimulus exposure or training in-between the two scans. ...
Article
Both hemispheres are engaged in recovery from word production deficits in aphasia. Lexical therapy has been shown to induce brain reorganization even in patients with chronic aphasia. However, the interplay of factors influencing reorganization patterns still remains unresolved. We were especially interested in the relation between lesion site, therapy-induced recovery, and beneficial reorganization patterns. Thus, we applied intensive lexical therapy, which was evaluated with functional magnetic resonance imaging, to 14 chronic patients with aphasic word retrieval deficits. In a group study, we aimed to illuminate brain reorganization of the naming network in comparison with healthy controls. Moreover, we intended to analyse the data with joint independent component analysis to relate lesion sites to therapy-induced brain reorganization, and to correlate resulting components with therapy gain. As a result, we found peri-lesional and contralateral activations basically overlapping with premorbid naming networks observed in healthy subjects. Reduced activation patterns for patients compared to controls before training comprised damaged left hemisphere language areas, right precentral and superior temporal gyrus, as well as left caudate and anterior cingulate cortex. There were decreasing activations of bilateral visuo-cognitive, articulatory, attention, and language areas due to therapy, with stronger decreases for patients in right middle temporal gyrus/superior temporal sulcus, bilateral precuneus as well as left anterior cingulate cortex and caudate. The joint independent component analysis revealed three components indexing lesion subtypes that were associated with patient-specific recovery patterns. Activation decreases (i) of an extended frontal lesion disconnecting language pathways occurred in left inferior frontal gyrus; (ii) of a small frontal lesion were found in bilateral inferior frontal gyrus; and (iii) of a large temporo-parietal lesion occurred in bilateral inferior frontal gyrus and contralateral superior temporal gyrus. All components revealed increases in prefrontal areas. One component was negatively correlated with therapy gain. Therapy was associated exclusively with activation decreases, which could mainly be attributed to higher processing efficiency within the naming network. In our joint independent component analysis, all three lesion patterns disclosed involved deactivation of left inferior frontal gyrus. Moreover, we found evidence for increased demands on control processes. As expected, we saw partly differential reorganization profiles depending on lesion patterns. There was no compensatory deactivation for the large left inferior frontal lesion, with its less advantageous outcome probably being related to its disconnection from crucial language processing pathways. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
... A classification of lesion types may be useful in model-oriented therapy of lexical disorders. In a previous study (Abel et al., 2007), we performed lexical therapy for 10 out of the 15 patients presented here. We were able to show that a connectionist diagnosis of naming disorders was a reasonable starting point for therapy planning and evaluation, but we did not specify and discuss the goodness of model fit in these patients. ...
... Patients were administered further testing (and lexical therapy, cf. Abel et al., 2007) if they demonstrated relatively low naming performance. Thus 15 patients were administered the first naming test (T1), and 12 of these patients were also administered a second naming test (T2). ...
Article
Analyzing and comparing characteristics of the English versus German lexicon, we were able to show that the model can also apply to German naming data. In this study we present nine German speaking aphasic patients to, for the first time, compare the predictive power of the single- versus the dual-route model of word repetition.
... Although these results demonstrate that a longer practice period can enhance learning, the improvements in naming once again faded after regular practice ceased. Dressel et al. (2010) examined whether using phonological and semantic cueing hierarchies, a technique reported to be effective in post-stroke aphasia therapy (Abel et al., 2007), might also enhance naming ability in SD. Their patient, BF, received naming treatment daily for a four-week period. ...
Article
Semantic Dementia (SD) is a neurodegenerative disease characterised by progressive deterioration of semantic knowledge, resulting in diminished understanding of concepts, whether encountered in verbal or non-verbal form. Over the past three decades, a number of studies employing a range of treatment techniques and learning methods have examined whether patients with SD can relearn previously known concepts or learn and retain new information. In this article, we review this research, addressing two main questions: a) Can aspects of semantic knowledge that are ‘lost’ due to degeneration be re-acquired? b) How much do other memory systems (working and episodic memory) interact with and depend on semantic memory? Several studies demonstrate successful relearning of previously known words and concepts in SD, particularly after regular, prolonged practice; but this success tends to diminish once practice ceases, and furthermore often fails to generalise to other instances of the same object/concept. This pattern suggests that, with impaired semantic knowledge, learning relies to an abnormal extent on perceptual factors, making it difficult to abstract away from the specific visual or other perceptual format in which a given concept has been trained. Furthermore, the impact of semantic ‘status’ of a word or object on both working and episodic memory indicates pervasive interaction of these other memory systems with conceptual knowledge.
... There exist several settings in which tools such these may find applications. There are a variety of highly accurate and informative assessment techniques that are regularly used in research settings but rarely used in clinical practice due to the large amount of effort they require for delivery and scoring (Edmonds and Kiran, 2006;Abel et al., 2007;Kendall et al., 2013;Minkina et al., 2015;Walker and Hickok, 2016); automation has the potential to streamline this process greatly, thereby enabling their clinical use. Additionally, automation of this sort would be a key part in many telemedicine and remote assessment scenarios, which is an area of great clinical interest (Van De Sandt-Koenderman, 2004;Kiran et al., 2014) as there exist major challenges around access to care for many individuals in need of speech and language services (Hou et al., 2023). ...
... This analysis approach provided an overall assessment of the ability of the PNT short forms to reproduce response-type profiles associated with the full test on an easily interpretable scale in a way that could be readily compared to Schwartz et al.'s (2006) previous investigation of the SP model's fit to empirical PNT response profiles. In that work, individual fits obtaining proportion RMSD values < 0.041 were deemed adequate, and other users of the SP model (Abel et al., 2007) have also adopted this criterion. Although the applicability of this criterion in the present case, where we are examining agreement between two independent administrations of the PNT rather than the fit of an explanatory computational model to a single administration, is arguable, it nevertheless provides a starting point for interpretation of the results. ...
Article
Full-text available
Purpose The purpose of this study was to evaluate whether a short-form computerized adaptive testing (CAT) version of the Philadelphia Naming Test (PNT) provides error profiles and model-based estimates of semantic and phonological processing that agree with the full test. Method Twenty-four persons with aphasia took the PNT-CAT and the full version of the PNT (hereinafter referred to as the “full PNT”) at least 2 weeks apart. The PNT-CAT proceeded in two stages: (a) the PNT-CAT30, in which 30 items were selected to match the evolving ability estimate with the goal of producing a 50% error rate, and (b) the PNT-CAT60, in which an additional 30 items were selected to produce a 75% error rate. Agreement was evaluated in terms of the root-mean-square deviation of the response-type proportions and, for individual response types, in terms of agreement coefficients and bias. We also evaluated agreement and bias for estimates of semantic and phonological processing derived from the semantic–phonological interactive two-step model (SP model) of word production. Results The results suggested that agreement was poorest for semantic, formal, mixed, and unrelated errors, all of which were underestimated by the short forms. Better agreement was observed for correct and nonword responses. SP model weights estimated by the short forms demonstrated no substantial bias but generally inadequate agreement with the full PNT, which itself showed acceptable test–retest reliability for SP model weights and all response types except for formal errors. Discussion Results suggest that the PNT-CAT30 and the PNT-CAT60 are generally inadequate for generating naming error profiles or model-derived estimates of semantic and phonological processing ability. Post hoc analyses suggested that increasing the number of stimuli available in the CAT item bank may improve the utility of adaptive short forms for generating error profiles, but the underlying theory also suggests that there are limitations to this approach based on a unidimensional measurement model. Supplemental Material https://doi.org/10.23641/asha.22320814
... Auf der segmentalen Leseroute werden die folgenden drei Unterkomponenten unterschieden: Graphem-Analyse, Graphem-Phonem-Konversion und Phonem-Synthese (Larsen et al., 2015). Im ers- (Abel et al., 2007;Abu-Rabia & Taha, 2004;Dell et al., 1997;Tochadse et al., 2018). ...
Thesis
Die vorliegende Dissertation verfolgt das Ziel, die diagnostischen Möglichkeiten für das Stö-rungsbild der erworbenen Dyslexie bei deutschsprachigen Personen mit Dyslexie (PmD) zu erweitern und zu spezifizieren. In der Literatur werden verschiedene Sprachverarbeitungsmodelle diskutiert, die den kognitiven Prozess der Schriftsprachverarbeitung zu erklären versuchen. Alle Überlegungen, Erhebungen und Analysen dieser Dissertation fußen auf den theoretischen Annahmen des kognitiven Zwei-Routen-Lesemodells, welches zwischen lexikalisch-semantischer und segmentaler, sub-lexikalischer Verarbeitung beim Lesen unterscheidet und so die voneinander unabhängigen Fähigkeiten zum Lesen bekannter und unbekannter Wörter abbilden kann. Mit dem im Rahmen der Dissertation entwickelten, kognitiv orientierten Diagnostikverfahren DYMO (Dyslexie Mo-dellorientiert) soll durch die Erhebung der Lesefähigkeiten von PmD eine möglichst genaue modelltheoretische Verortung der Lesebeeinträchtigung erreicht und eine Grundlage für die Planung einer lesebezogenen Therapie geschaffen werden. Dabei werden auch Modellkomponenten des Zwei-Routen-Lesemodells berücksichtigt, die bisher im deutschsprachigen Raum noch nicht etabliert sind. Dazu zählen Unterkomponenten der Visuellen Analyse, die für die Identifikation von Buchstaben und das Kodieren von Buchstabenpositionen verantwortlich sind und Unterkomponenten der segmentalen Leseroute, die den einzelheitlichen Leseprozess auf dieser Modellroute schrittweise abbilden. Das Itemmaterial aus DYMO ist nach diversen psycholinguistisch kontrollierten Variablen kontrolliert. Hierbei werden auch Variablen berücksichtigt, die bisher in der Dyslexiediagnostik für deutschsprachige PmD nicht systematisch erfasst werden können, wie die Wortlänge und die graphematische Komplexität von Pseudowörtern. Die erste dieser Dissertation zugrundeliegende Publikation (Originalarbeit I) befasst sich mit den Parametern und Modellkomponenten, die für eine umfassende modelltheoretisch basierte Di-agnostik bei erworbener Dyslexie entscheidend sind. Es werden außerdem Überlegungen zu Fehlertypen-Kategorisierung angestellt. Die zweite Publikation (Originalarbeit II) stellt das Testverfahren DYMO dar. Das dazugehörige Handbuch liefert detaillierte Informationen zum Aufbau und der Konstruktion des Testverfah-rens, zur Durchführung und Auswertung der einzelnen Untertests und zur Einstufung einer Leistung in einen Leistungsbereich. Anhand von ausführlich beschriebenen Fallbeispielen zweier PmD werden die Durchführung, Auswertung, Interpretation und das Ableiten von Therapiezielen dargestellt. Die Ergebnisse dieser Fallbeschreibungen verdeutlichen die diagnostische Ergänzung durch DYMO und zeigen, dass das explizite Untersuchen der Unterkomponenten der Visuellen Analyse und der segmentalen Leseroute sowie der Einbezug der Variablen Wortlänge und gra-phematische Komplexität den Lesebefund spezifizieren und den Therapieeinstieg konkretisieren können. Die dritte Publikation (Originalarbeit III) zeigt in einer systematischen Vergleichsstudie anhand einer Fallserie von zwölf PmD die Unterschiede zwischen dem Diagnostikverfahren DYMO und einem weiteren kognitiv basierten Diagnostikverfahren. Es wird diskutiert, inwieweit DYMO eine sinnvolle Ergänzung im Diagnostikprozess erworbener Dyslexien darstellen kann. Außerdem werden leicht und schwer beeinträchtigte PmD in Gruppenanalysen verglichen, um zu prüfen, ob DYMO insbesondere bei leicht beeinträchtigten PmD eine Ergänzung bieten kann. Aufgrund des komplexeren Itemmaterials von DYMO (beispielsweise aufgrund der Kontrolle der Wortlänge) wurde angenommen, dass leicht beeinträchtigte PmD in DYMO-Untertests auffälligere Leseleistungen zeigen als in Aufgaben des gegenübergestellten anderen Diagnostikverfahrens. Diese Hypothese konnte teilweise bestätigt werden. Leicht beeinträchtigte PmD zeigten häufiger Längeneffekte als schwer beeinträchtigte PmD. Insgesamt fiel der Gruppenunterschied jedoch nicht so deutlich aus, wie erwartet. Mit dem kriteriumsorientiert normierten und finalisierten Material von DYMO wurden 17 PmD getestet. Ausführliche Befunde für jede einzelne PmD mit darauffolgenden Therapieimplikationen zeigen, dass insbesondere die Spezifizierung eines segmentalen Lesedefizits bei einer schwer beeinträchtigten Leistung im Lesen von Pseudowörtern zur erweiterten Aussage bezüglich des modelltheoretischen Störungsortes beitragen kann. Dies verdeutlicht die hohe Aussagekraft der DYMO-Untertests und die Relevanz einer spezifischen und detaillierten modellbasierten Befunderhebung für eine explizite, individuelle Therapieplanung bei erworbenen Dyslexien.
... These models depict naming activation patterns and possible breakdowns-at the semantic processing level, the phonological processing level, and/or links between these levels-that can lead to naming errors. These models provide a useful template for creating paradigms to treat aphasic naming deficits (i.e., anomia) (e.g., Abel et al., 2007;Schwartz et al., 2006). Harnish et al. (2014) reviewed semantic-based approaches to treating single-word naming deficits. ...
Article
In this study, we compared the orthographic and semantic preferences of healthy adults and age and gender matched adults with aphasia, an acquired language disorder. Previous research in word retrieval and word associations has addressed semantic and phonological connections, but it has not as often included analyses of orthographic skills. We matched (on age and gender) 10 neurotypical adults and 11 older adults with aphasia and administered to both groups a lexical discrimination task requiring them to select, from 18 choices, those words that were most different from three words (daughter, laughter, son). Among the choices were foil words (e.g., daughter), orthographic similarities (laughter) and semantic similarities (son). Results revealed that individuals with aphasia focused on orthographic differences, while healthy adults chose semantic differences. Further studies should further explore this orthographic focus to develop treatment strategies, using behavioral and objective measures, for word-finding deficits in aphasia.
... (Vgl. Abel et al. 2007in Grötzbach 2015 ...
Chapter
Dieses Kapitel beschäftigt sich mit der Planung und den Rahmenbedingungen einer Aphasie-Therapie. Fragen der Wirksamkeit und ICF-orientierten Zielsetzung der Therapie werden ebenso behandelt wie die unterschiedliche Ausrichtung der Therapie im Verlauf einer Aphasie. Zahlreiche Faktoren, die bei der Therapieplanung zu berücksichtigen sind, werden erläutert. Hierzu gehören z. B. Beginn und Intensität einer Therapie oder Auswahlkriterien für Übungen und Material.
... Thus, speech errors, which are a common manifestation of anomia, can be important indicators of underlying wordretrieval mechanisms (Schwartz, Dell, Martin, Gahl, & Sobel, 2006;Schwartz, 2014). In contrast to broader (and more commonly used) measures, such as overall naming accuracy, changes in speech error production pre-to post-treatment may elucidate some of the factors driving treatment-related improvements (Abel, Willmes, & Huber, 2007;Jokel, Rochon, & Leonard, 2004;Kendall, Pompon, Brookshire, Minkina, & Bislick, 2013;Minkina et al., 2016), and may provide more nuanced insights into the mechanisms underlying generalization. ...
Article
Treatments for anomia have demonstrated short- and long-term efficacy. However, individual outcomes can be variable, and evidence for treatment generalization is limited. We investigated whether treatment techniques which stimulate access to- and learning of language, namely, a) responsiveness to cues, and b) during-treatment improvements in naming, are good predictors of treatment outcomes. In addition, we investigated mechanisms underlying treatment generalization. Ten adults with chronic, post-stroke aphasia received a phonological treatment for anomia three times a week for five weeks. Naming accuracy of treated and untreated words was assessed pre- and post-treatment and at four- and eight-week follow-ups. Generalization to an untrained naming task, which involved analyses of naming accuracy and speech errors, was also assessed; speech errors were analyzed according to the Interactive Activation (IA) model of word retrieval. Group analyses indicate significant improvements in naming treated compared to untreated words, at all timepoints after therapy. Additional analyses showed significant long-term improvements in naming untreated words. Initial responsiveness to cueing and early improvement emerged as significant predictors of overall pre- to post-treatment improvements in naming treated words; naming improvements made early-on in treatment were also predictive of improvements in naming of the untreated words at follow-up. Furthermore, our study is the first to demonstrate that generalization after a phonological treatment for anomia may be driven by a strengthening of lexical-phonological connections. This study provides novel insights regarding mechanisms driving anomia treatment outcomes. Understanding such mechanisms is critical to improving existing assessment practices, optimizing treatment selection and building treatment protocols that are more likely to generalize.
... Unlike other prominent computational models of aphasic language behaviour (Ueno et al., 2011;Roelofs, 2014), the model can be fit to personlevel data from individuals with aphasia, providing estimates of s and p for each person depending on the pattern of responses to a confrontation naming test. Furthermore, given the SP model's notable success in modelling aphasic word-production performance (Schwartz et al., 2006;Dell et al., 2007) and evidence supporting its diagnostic value (Schwartz and Brecher, 2000;Abel et al., 2007Abel et al., , 2009Dickey et al., 2016), identifying its potential neural correlates is of significant theoretical and clinical interest. ...
Article
While current dual-steam neurocognitive models of language function have coalesced around the view that distinct neuroanatomic-al networks subserve semantic and phonological processing, respectively, the specific white matter components of these networks remain a matter of debate. To inform this debate, we investigated relationships between structural white matter connectivity and word production in a cross-sectional study of 42 participants with aphasia due to unilateral left hemisphere stroke. Specifically, we reconstructed a local connectome matrix for each participant from diffusion spectrum imaging data and regressed these matrices on indices of semantic and phonological ability derived from their responses to a picture-naming test and a computational model of word production. These connectometry analyses indicated that both dorsally located (arcuate fasciculus) and ventrally located (inferior frontal-occipital, uncinate, and middle longitudinal fasciculi) tracts were associated with semantic ability, while associations with phonological ability were more dorsally situated, including the arcuate and middle longitudinal fasciculi. Associations with limbic pathways including the posterior cingulum bundle and the fornix were also found. All analyses controlled for total le-sion volume and all results showing positive associations obtained false discovery rates 5 0.05. These results challenge dual-stream accounts that deny a role for the arcuate fasciculus in semantic processing, and for ventral-stream pathways in language production. They also illuminate limbic contributions to both semantic and phonological processing for word production.
... One of the therapies investigated involved a hierarchy of semantic cues d . The order of semantic cues provided in this particular hierarchy were: (a) the superordinate class of the target word, (b) definition, (c) a closure sentence, and (d) auditory target comprehension (see Abel, Willmes, & Huber, 2007, from which this semantic cue hierarchy was based on). ...
Article
Full-text available
Background Spoken word retrieval therapy forms an integral part of aphasia therapy. Due to the range of therapy options and variations, drawing clear-cut conclusions from the evidence base can be challenging. Aims This paper consolidates recent findings (2008–2018), pertinent to spoken word-finding interventions. Specifically, we are interested in aphasia interventions: (1) that target single-word spoken naming; (2) whose participants are adults with acquired naming impairments after a stroke; and (3) whose treatment approach focusses on the use of language forms (i.e., semantics, phonology, and orthography). The over-arching objective is to determine the important therapy components underpinning successful single-word naming treatments. Methods and Procedures A systematic literature search was conducted. This led to the compilation of a large-scale dataset (n=222 participants from 32 papers), with the heterogenous interventions dissected into their “active” therapy components. A detailed framework (“RITA”: (1) Regimen; (2) Item(s); (3) Technique(s); and (4) Application of technique(s) with their Adjuncts) was designed to organise these “active therapy ingredients”. Using random forest, we identified the crucial components responsible for the successful naming of treated and untreated items, respectively, at short-term and maintenance periods. Outcomes and Results The role of the written form as therapeutic cues, presented either as a whole word or part-word, emerged to be a consistent and robust predictor, across the outcomes. Semantic tasks were useful in the successful naming of untreated items. Conclusions Clinicians should consider using written prompts as part of spoken naming therapy. It is possible that the use of orthography underlies the success of multi-component techniques. Other clinical implications (e.g., homework, treatment intensity) are also discussed. In addition, we propose a comprehensive “RITA” framework, which summarises the “active” therapy components. “RITA” (available as a template in Appendix 3) is useful for clinicians and researchers as a guide to unpack language interventions. Furthermore, the paper highlights the strengths of a well-established method, random forest, as a valuable statistical tool to move aphasia research forward. Overall, the study refines our understanding of spoken naming treatment for those with aphasia, specifically individuals with word-finding deficits. Importantly, through the use of a robust statistical approach and an original framework designed to lay out language therapy components, the paper adds new clarity to the evidence base.
... Step (I) impairment-based exercises Impairment-based exercises consisted of (a) a confrontation naming task, (b) naming from verbal description by the SLP, and (c) nonverbal expression of the spoken word delivered by the SLP. An increasing hierarchy of assistance which is well-known in aphasia therapy (Abel, Willmes, & Huber, 2007;Nickels, 2002) was used, which consisted of (i) a semantic cue, (ii) a phonological cue and (iii) a semantic closure sentence. ...
Article
Purpose: Over and above language deficits, persons with aphasia can present with impairments in executive functions, including deficits in cognitive flexibility. Cognitive flexibility constitutes the ability to update behaviour quickly and flexibly in a changing environment. Its deficits can restrict communicative ability, e. g. the ability to change a topic. To date, these deficits have been neglected in aphasia therapy, even though their consideration regarding language treatment may be beneficial for the persons affected. The present study aimed to evaluate whether aphasia therapy including cognitive flexibility leads to more improvement than conventional aphasia therapy. Method: A pilot group study with ten patients was conducted. The patients received both the novel Cognitive Flexibility in Aphasia Therapy (CFAT) and conventional aphasia therapy in a cross-over design. Each therapy method was delivered for 20 sessions within two weeks. An assessment battery was applied five times, including language skills, communicative ability and verbal/nonverbal cognitive flexibility. Result: Patients profited from CFAT regarding language skills, communicative ability and verbal cognitive flexibility. Furthermore, compared to conventional therapy, CFAT was more effective for verbal cognitive flexibility. Conclusion: This pilot study indicates that CFAT offers a novel opportunity to directly train cognitive flexibility in communicative settings and complements conventional therapy for optimal patient outcome.
... Among the most productive of these has been the semanticphonological two-step interactive activation model (Foygel & Dell, 2000). This computational model successfully reproduces key features of naming performance by PWA and provides parameter estimates, based on naming error profiles of individual PWA, that usefully correspond to lexical-semantic and phonological processing ability (Abel et al., 2009(Abel et al., , 2007Dell et al., 2013;Tochadse et al., 2018). Basic item response theory models have also been applied to the task of developing a calibrated item bank and computer adaptive assessment of overall naming ability in aphasia Fergadiotis et al., 2015). ...
Article
Full-text available
Purpose Aphasia is a language disorder caused by acquired brain injury, which generally involves difficulty naming objects. Naming ability is assessed by measuring picture naming, and models of naming performance have mostly focused on accuracy and excluded valuable response time (RT) information. Previous approaches have therefore ignored the issue of processing efficiency, defined here in terms of optimal RT cutoff, that is, the shortest deadline at which individual people with aphasia produce their best possible naming accuracy performance. The goals of this study were therefore to (a) develop a novel model of aphasia picture naming that could accurately account for RT distributions across response types; (b) use this model to estimate the optimal RT cutoff for individual people with aphasia; and (c) explore the relationships between optimal RT cutoff, accuracy, naming ability, and aphasia severity. Method A total of 4,021 naming trials across 10 people with aphasia were scored for accuracy and RT onset. Data were fit using a novel ex-Gaussian multinomial RT model, which was then used to characterize individual optimal RT cutoffs. Results Overall, the model fitted the empirical data well and provided reliable individual estimates of optimal RT cutoff in picture naming. Optimal cutoffs ranged between approximately 5 and 10 s, which has important implications for assessment and treatment. There was no direct relationship between aphasia severity, naming RT, and optimal RT cutoff. Conclusion The multinomial ex-Gaussian modeling approach appears to be a promising and straightforward way to estimate optimal RT cutoffs in picture naming in aphasia. Limitations and future directions are discussed.
... Thus, speech errors, which are a common manifestation of anomia, can be important indicators of underlying wordretrieval mechanisms (Schwartz, Dell, Martin, Gahl, & Sobel, 2006;Schwartz, 2014). In contrast to broader (and more commonly used) measures, such as overall naming accuracy, changes in speech error production pre-to post-treatment may elucidate some of the factors driving treatment-related improvements (Abel, Willmes, & Huber, 2007;Jokel, Rochon, & Leonard, 2004;Kendall, Pompon, Brookshire, Minkina, & Bislick, 2013;Minkina et al., 2016), and may provide more nuanced insights into the mechanisms underlying generalization. ...
... Given the naming activation patterns depicted in these models, breakdowns at the semantic processing level, the phonological processing levels, or links between the levels can lead to naming errors. Thus, these models provide a useful template in constructing paradigms designed to treat naming deficits, or anomia, in aphasia (e.g., Abel, Willmes, & Huber, 2007;Dell, Schwartz, Martin, & Saffran, 1997;Foygel & Dell, 2000;Laine & Martin, 1996;Matti, Anneli, & Martti, 1998;Roelofs, 2006;Schwartz, Dell, Martin, Gahl, & Sobel, 2006). Of particular interest in this study are semantic-based approaches that are aimed toward treating single-word noun naming deficits. ...
Article
Full-text available
Purpose: The aims of the study were to investigate the use of semantic associative relationships as primes in treating naming deficits, or anomia, in aphasia and to determine if differential treatment effects would be found if 1 or 3 primes were presented. Method: Ten individuals with varying degrees of anomia participated in the study. A single-subject, A-B treatment design with a cross-over component was used. A 1-PRIME condition (use of 1 prime) was compared with a 3-PRIMES condition (use of 3 primes) for each participant. Results: Visual analyses of treatment data revealed improvements in 8 of 10 participants. Meaningful effect sizes were obtained in at least 1 of the conditions for 6 of the 10 participants. Slightly more participants demonstrated meaningful effect sizes in the 3-PRIMES condition than in the 1-PRIME condition. Correlation analyses revealed a positive correlation between the number of teaching episodes and 3-PRIMES probe performance. Conclusions: The results support a protocol that uses semantic associative primes to increase naming accuracy in aphasia. The 3-PRIMES condition was slightly more beneficial than the 1-PRIME condition in terms of improving naming abilities in these participants, but there was no overwhelming advantage in using one or the other condition. A lthough single-word production models vary in architectural details and processing assumptions, all models assume that naming a picture involves activation of at least a semantic processing level and a phonological processing level (e.g. a review of models). Given the naming activation patterns depicted in these models, breakdowns at the semantic processing level, the phonological processing levels, or links between the levels can lead to naming errors. Thus, these models provide a useful template in constructing paradigms designed to treat naming deficits, or anomia, in aphasia (e.g.,
... Wambaugh et al., 2001). Additionally, studies that have combined phonological and semantic information into cueing hierarchies have resulted in improved word finding (Abel, Schultz, Radermacher, Willmes, & Huber, 2005;Abel, Willmes, & Huber, 2007;Cameron, Wambaugh, Wright, & Nessler, 2006;Conroy, Sage, & Lambon Ralph, 2009;Doesborgh et al., 2004;Fink, Brecher, Schwartz, & Robey, 2002;Herbert, Best, Hickin, Howard, & Osborne, 2003). Interestingly, some studies have shown better recovery of naming in persons with phonologically-based anomia after semantically focused training (A. ...
... It was suggested that, among all, Broca's and conduction aphasia patients show the highest responsiveness to cueing 10 . Indeed, both phonemic and semantic priming were shown highly beneficial in word retrieval trainings and are widely practiced in clinical setups 11 . In the following sections, we discuss evidence from neurophysiological research 12 13 which leads us to propose and test an alternative type of cueing, namely, silent visuomotor (SVC). ...
Conference Paper
Full-text available
About a quarter of stroke patients worldwide suffer serious language disorders such as aphasias. Most common symptoms of Broca's aphasia are word naming disorders which highly impact verbal communication and the quality of life of aphasic patients. In order to recover disturbances in word retrieval, several cueing methods (i.e. phonemic and semantic) have been established to improve lexical access establishing effective language rehabilitation techniques. Based on recent evidence from action-perception theories, which postulate that neural circuits for speech perception and articulation are tightly coupled, in the present work, we propose and investigate an alternative type of cueing using silent articulation-related visual stimuli. We hypothesize that providing patients with primes in the form of silent videos showing lip motions representative of correct pronunciation of target words, will result in faster word retrieval than when no such cue is provided. To test our prediction, we realize a longitudinal clinical virtual reality-based trial with four post-stroke Broca's patients and compare the interaction times between the two conditions over the eight weeks of the therapy. Our results suggest that silent visuomotor cues indeed facilitate word retrieval and verbal execution, and might be beneficial in lexical relearning in chronic Broca's patients.
... These profiles could also be clinically useful for developing individualized intervention plans (Abel, Willmes, & Huber, 2007), but classifying errors from confrontation naming tests is time consuming and often it is not performed in fast-paced clinical settings. Therefore, there is a need to develop efficient and psychometrically robust tools to quantify impairment along more than a single dimension. ...
Article
Full-text available
Purpose This study was intended to evaluate a series of algorithms developed to perform automatic classification of paraphasic errors (formal, semantic, mixed, neologistic, and unrelated errors). Method We analyzed 7,111 paraphasias from the Moss Aphasia Psycholinguistics Project Database (Mirman et al., 2010) and evaluated the classification accuracy of 3 automated tools. First, we used frequency norms from the SUBTLEXus database (Brysbaert & New, 2009) to differentiate nonword errors and real-word productions. Then we implemented a phonological-similarity algorithm to identify phonologically related real-word errors. Last, we assessed the performance of a semantic-similarity criterion that was based on word2vec (Mikolov, Yih, & Zweig, 2013). Results Overall, the algorithmic classification replicated human scoring for the major categories of paraphasias studied with high accuracy. The tool that was based on the SUBTLEXus frequency norms was more than 97% accurate in making lexicality judgments. The phonological-similarity criterion was approximately 91% accurate, and the overall classification accuracy of the semantic classifier ranged from 86% to 90%. Conclusion Overall, the results highlight the potential of tools from the field of natural language processing for the development of highly reliable, cost-effective diagnostic tools suitable for collecting high-quality measurement data for research and clinical purposes. Supplemental Material https://doi.org/10.23641/asha.14963559
... Given the naming activation patterns depicted in these models, breakdowns at the semantic processing level, the phonological processing levels, or links between the levels can lead to naming errors. Thus, these models provide a useful template in constructing paradigms designed to treat naming deficits, or anomia, in aphasia (e.g., Abel, Willmes, & Huber, 2007;Dell, Schwartz, Martin, & Saffran, 1997;Foygel & Dell, 2000;Laine & Martin, 1996;Matti, Anneli, & Martti, 1998;Roelofs, 2006;Schwartz, Dell, Martin, Gahl, & Sobel, 2006). Of particular interest in this study are semantic-based approaches that are aimed toward treating single-word noun naming deficits. ...
Article
Full-text available
Purpose The aims of the study were to investigate the use of semantic associative relationships as primes in treating naming deficits, or anomia, in aphasia and to determine if differential treatment effects would be found if 1 or 3 primes were presented. Method Ten individuals with varying degrees of anomia participated in the study. A single-subject, A-B treatment design with a cross-over component was used. A 1-PRIME condition (use of 1 prime) was compared with a 3-PRIMES condition (use of 3 primes) for each participant. Results Visual analyses of treatment data revealed improvements in 8 of 10 participants. Meaningful effect sizes were obtained in at least 1 of the conditions for 6 of the 10 participants. Slightly more participants demonstrated meaningful effect sizes in the 3-PRIMES condition than in the 1-PRIME condition. Correlation analyses revealed a positive correlation between the number of teaching episodes and 3-PRIMES probe performance. Conclusions The results support a protocol that uses semantic associative primes to increase naming accuracy in aphasia. The 3-PRIMES condition was slightly more beneficial than the 1-PRIME condition in terms of improving naming abilities in these participants, but there was no overwhelming advantage in using one or the other condition.
... Furthermore, the efficacy of different treatments may vary with the functional locus of naming impairment, which can involve one or several stages of processing in the course of word retrieval (i.e., object recognition/ categorization, word selection, word form retrieval, postlexical/articulatory operations). This echoes a prevalent assumption in naming treatment research that the devised treatment should target the disrupted process(es) implicated in the impairment (e.g., Abel, Willmes, & Huber, 2007;Nickels, 2002). However, in addition to an analysis of the underlying functional impairment, we assert, as have others (Baddeley, 1993;Stark, 2005), that a model of how the damaged system changes with experience (a theory of learning) is critical for optimizing rehabilitation. ...
Article
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Purpose The purpose of this article was to examine how different types of learning experiences affect naming impairment in aphasia. Methods In 4 people with aphasia with naming impairment, we compared the benefits of naming treatment that emphasized retrieval practice (practice retrieving target names from long-term memory) with errorless learning (repetition training, which preempts retrieval practice) according to different schedules of learning. The design was within subjects. Items were administered for multiple training trials for retrieval practice or repetition in a spaced schedule (an item's trials were separated by multiple unrelated trials) or massed schedule (1 trial intervened between an item's trials). In the spaced condition, we studied 3 magnitudes of spacing to evaluate the impact of effortful retrieval during training on the ultimate benefits conferred by retrieval practice naming treatment. The primary outcome was performance on a retention test of naming after 1 day, with a follow-up test after 1 week. Results Group analyses revealed that retrieval practice outperformed errorless learning, and spaced learning outperformed massed learning at retention test and at follow-up. Increases in spacing in the retrieval practice condition yielded more robust learning of retrieved information. Conclusion This study delineates the importance of retrieval practice and spacing for treating naming impairment in aphasia. Supplemental Material https://doi.org/10.23641/asha.14963925
... Both phonological and sematic cueing have previously proved to be effective in nfvPPA (Henry et al., 2008;Jokel et al., 2014). Moreover, some studies on word-retrieval disorders in post-stroke aphasia have described semantic cues as being effective, even if the impairment is primarily phonological (Abel, Willmes, & Huber, 2007;Raymer & Ellsworth, 2002). Additionally, studies on individuals with Broca's aphasia showed significant word-retrieval improvements following a treatment with combined phonological and semantic cueing (Kleine-Katthöfer, 2012;Wambaugh, Cameron, Kalinzak-Fliszar, Nessler, & Wright, 2004). ...
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Background: Much recent progress has been made in developing speech–language therapy in primary progressive aphasia (PPA). Several treatment approaches that have shown significant effects with people with aphasia have been adapted and re-evaluated for PPA. Constraint-induced aphasia therapy (CIAT) is a well-evaluated method that has yielded significant language improvements in people with post-stroke aphasia but has not yet been evaluated with people with PPA. Nevertheless, the combination of CIAT features like massed practice and a motivating communicative setting seem likely to make it a suitable tool for improving the speech and language performance of individuals with PPA as well.Aims: This study investigates the effectiveness of a modified CIAT protocol on word retrieval, grammatical structure and connected speech in two individuals with non-fluent variant PPA (nfvPPA).Methods and procedures: Two participants with nfvPPA took part in a 9-day intensive CIAT-based group therapy with additional computer-based home training. Stimuli were 120 photos of people performing daily life activities, which could be described using a simple (e.g., “The man is mowing the lawn”) or reduced (e.g., “mowing the lawn”) sentence structure. During the treatment phase, the participants were required to request picture cards from other group members using spoken language only. The task difficulty was increased hierarchically (shaped) in accordance to each participant’s performance level.Outcomes and results: Directly after therapy, both participants achieved significant improvements in their noun and verb naming accuracy and their grammatical structure for trained items. Training effects were maintained 2 months after therapy. Moreover, generalisation to different pictures of the same item was found for both participants and one participant also showed improved grammatical structure when describing untrained pictures. No significant generalisation to untrained connected speech samples was observed for either participant.Conclusion: This study illustrates that CIAT can be effective in people with PPA. However, further modifications of CIAT should be considered to facilitate generalisation and in order to determine which aspects of the treatment are most important.
... Despite a rich and complex literature, there have been relatively few studies which have applied connectionist principles to neurorehabilitation. The few available language-focused studies have tended to address anomia (e.g., Abel, Huber, & Dell, 2009;Abel, Willmes, & Huber, 2007) and compared different connectionist models in terms of their utility for treating symptoms and predicting therapy gains. Similar to work within connectionist modelling of reading and dyslexia, studies on dysgraphia have modelled spelling acquisition and breakdown in simulations of brain damage (e.g., Loosemore, Brown, & Watson, 1991) but not yielded treatment principles and investigations. ...
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Writing therapy studies have been predominantly uni-modal in nature; i.e., their central therapy task has typically been either writing to dictation or copying and recalling words. There has not yet been a study that has compared the effects of a uni-modal to a multi-modal writing therapy in terms of improvements to spelling accuracy. A multiple-case study with eight participants aimed to compare the effects of a uni-modal and a multi-modal therapy on the spelling accuracy of treated and untreated target words at immediate and follow-up assessment points. A cross-over design was used and within each therapy a matched set of words was targeted. These words and a matched control set were assessed before as well as immediately after each therapy and six weeks following therapy. The two approaches did not differ in their effects on spelling accuracy of treated or untreated items or degree of maintenance. All participants made significant improvements on treated and control items; however, not all improvements were maintained at follow-up. The findings suggested that multi-modal therapy did not have an advantage over uni-modal therapy for the participants in this study. Performance differences were instead driven by participant variables.
... Models have considered rehabilitation after acquired damage in adulthood. Abel, Willmes, and Huber (2007) sought to show how an adult model of aphasia could guide actual interventions depending on patients' error patterns, while Plaut (1996) explored which training regimes might aid recovery from acquired dyslexia manipulating item typicality. In other work, we have begun to explore the computational foundations of intervening to improve performance in atypically developing connectionist learning systems . ...
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We evaluated a simple computational model of productive vocabulary acquisition, applied to simulating two case studies of 7-year-old children with developmental word-finding difficulties across four core behavioural tasks. Developmental models were created, which captured the deficits of each child. In order to predict the effects of intervention, we exposed the computational models to simulated behavioural interventions of two types, targeting the improvement of either phonological or semantic knowledge. The model was then evaluated by testing the predictions from the simulations against the actual results from an intervention study carried out with the two children. For one child it was predicted that the phonological intervention would be effective, and the semantic intervention would not. This was borne out in the behavioural study. For the second child, the predictions were less clear and depended on the nature of simulated damage to the model. The behavioural study found an effect of semantic but not phonological intervention. Through an explicit computational simulation, we therefore employed intervention data to evaluate our theoretical understanding of the processes underlying acquisition of lexical items for production and how they may vary in children with developmental language difficulties.
... Our findings concur with the claim that it is possible to use background language assessments to predict the outcome from cueing therapy (Hillis, 1989). Abel et al. (2007) delivered therapy according to predictions made about participants' underlying language profiles and also conclude that models can be informative when making decisions about which therapy to use. Interestingly, in their 2005 study no participants improved with vanishing cues only, but several showed positive effects with increasing cues alone (as in the present study) or with both increasing and vanishing cues. ...
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Introduction: The majority of adults with acquired aphasia have anomia which can respond to rehabilitation with cues. However, the literature and clinical consensus suggest change is usually limited to treated items. We investigated the effect of an experimentally controlled intervention using progressive cues in the rehabilitation of noun retrieval/production in 16 participants with chronic aphasia. Method: Participants were sub-divided relative to the group according to performance on semantic tasks (spoken/written word to picture matching) and phonological output processing (presence/absence of word length effect and proportion of phonological errors in picture naming) in order to investigate outcome in relation to language profile. Cueing therapy took place weekly for 8 weeks. Results: Intervention resulted in significant improvement on naming treated items for 15/16 participants, with stable performance on control tasks. Change occurred at the point of intervention and not during pre-therapy assessments. We predicted particular patterns of generalisation which were upheld. Only participants classified as having relatively less of a semantic difficulty and more of a phonological output deficit demonstrated generalisation to untreated items. Outcome did not relate to traditional aphasia classification. Conclusion: A cueing hierarchy can improve word retrieval/production for adults with aphasia. In some cases generalisation to untreated items also occurs. The study demonstrates that the results of behavioural testing can be used to guide predictions of recovery with intervention.
... In keeping with the evolving focus on processing aspects of language impairment, researchers are beginning to use computational models such as Dell's interactive activation model as frameworks to predict effects of therapy techniques such as priming or cueing based on dynamics of the treatment processes (Abel, Grande, Huber, Wilmes, & Dell, 2005;Abel, Huber, & Dell, 2009;Abel, Wilmes, & Huber, 2007;Martin, Fink, Renvall, & Laine, 2006). Koenig-Bruhin and Studer-Eichenberger (2007) investigated the effectiveness of a treatment to improve temporary storage of verbal information by a person with reproduction conduction aphasia. ...
Article
Background: Verbal short-term memory (STM) impairments are invariably present in aphasia. Word processing involves a minimal form of verbal STM, i.e., the time course over which semantic and phonological representations are activated and maintained until they are comprehended, produced, or repeated. Thus it is reasonable that impairments of word processing and verbal STM may co-occur. The co-occurrence of language and STM impairments in aphasia has motivated an active area of research that has revealed much about the relationship of these two systems and the effect of their impairment on language function and verbal learning (Freedman & Martin, 2001 Freedman, M. L. and R. Martin, R. C. 2001. Dissociable components of short-term memory and their relation to long-term learning. Cognitive Neuropsychology, 18: 193–226. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]; Martin & Saffran, 1999 Martin, N. and Saffran, E.M. 1999. Effects of word processing and short-term memory deficits on verbal learning: Evidence from aphasia. International Journal of Psychology, 34(5/6): 330–346. [Web of Science ®] , [Google Scholar]; Trojano & Grossi, 1995 Trojano, L. and Grossi, D. 1995. Phonological and lexical coding in verbal short-term-memory and learning. Brain and Language, 51(2): 336–354. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). In keeping with this view a number of researchers have developed treatment protocols to improve verbal STM in order to improve language function (e.g., Koenig-Bruhin & Studer-Eichenberger, 2007 Koenig-Bruhin, M. and Studer-Eichenberger, F. 2007. Therapy of verbal short-term memory disorders in fluent aphasia: A single case study. Aphasiology, 21(5): 448–458. [Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). This account of aphasia predicts that treatment of a fundamental ability, such as STM, which supports language function, should lead to improvements that generalise to content and tasks beyond those implemented in treatment. Aims: We investigated the efficacy of a treatment for language impairment that targets two language support processes: verbal short-term memory (STM) and executive processing, in the context of a language task (repetition). We hypothesised that treatment of these abilities would improve repetition abilities and performance on other language tasks that require STM. Method: A single-participant, multiple-baseline, multiple-probe design across behaviours was used with a participant with conduction aphasia. The treatment involved repetition of words and nonwords under three “interval” conditions, which varied the time between hearing and repeating the stimulus. Measures of treatment effects included acquisition, maintenance, and follow-up data, effect sizes, and pre- and post-treatment performance on a test battery that varies the STM and executive function demands of language tasks. Outcomes & Results: Improvement of repetition was mostly specific to treated stimuli. Post-treatment measures of language ability indicated improvements in single and multiple word processing tasks, verbal working memory tasks, and verbal span. Conclusions: Treatment of STM and executive processes in the context of a word repetition task resulted in improvements in other non-treated language tasks. The approach used in this study can be incorporated into other language-processing tasks typically used in treatment of language disorders (e.g., sentence processing).
Chapter
The Cambridge Handbook of Computational Cognitive Sciences is a comprehensive reference for this rapidly developing and highly interdisciplinary field. Written with both newcomers and experts in mind, it provides an accessible introduction of paradigms, methodologies, approaches, and models, with ample detail and illustrated by examples. It should appeal to researchers and students working within the computational cognitive sciences, as well as those working in adjacent fields including philosophy, psychology, linguistics, anthropology, education, neuroscience, artificial intelligence, computer science, and more.
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There is a growing body of literature demonstrating that language rehabilitation can improve naming impairments for individuals with aphasia. However, there are challenges applying evidence-based research to clinical practice. Well-controlled clinical studies often consist of homogenous samples and exclude individuals who may confound group-level results. Consequently, the findings may not generalize to the diverse clients serviced by speech-language therapists. Within evidence-based guidelines, clinicians can leverage their experiences and theoretical rationale to adapt interventions to meet the needs of individual clients. However, modifications to evidence-based interventions should not alter aspects of treatment that are necessary to produce change within the treatment target. The current discussion paper uses errorless learning, errorful learning, and retrieval practice for naming in aphasia to model how treatment theories can guide clinicians in making theory-informed modifications to interventions. First, we briefly describe the learning mechanisms hypothesized to underlie errorless learning, errorful learning, and retrieval practice. Next, we identify ways clinicians can provide targeted supports to optimize learning for individual clients. The paper ends with a reflection on how well-defined treatment theories can facilitate the generation of practice-based evidence and clinically relevant decision making.
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Besides language deficits, persons with aphasia (PWA) can have impairments in cognitive flexibility, which may influence communicative abilities negatively. The aim of the present study was to evaluate whether therapy including cognitive flexibility leads to improvement in language skills as well as in communicative abilities. 10 single case studies were conducted; two of them are presented in this paper. The PWA received in different order (cross-over design) both a novel therapy, the Cognitive Flexibility in Aphasia Therapy (CFAT), and conventional aphasia therapy in 20 sessions over a period of two weeks for each therapy method. The results indicate that more severely affected PWA benefit more from the CFAT regarding language skills as well as communicative abilities.
Article
There is a lack of clarity in the field regarding how to best predict which naming treatment will be most beneficial for a particular individual with aphasia. The purpose of this study was to elucidate whether or not semantic or phonological therapy differentially impacts on outcomes for people with a range of different aphasic profiles when given both therapies. A single-participant design, with multiple repeated baselines for naming, replicated across four participants, was used. Participants were provided with a counterbalanced order of Semantic Feature Analysis (SFA) and Phonological Components Analysis (PCA) treatment. Findings demonstrated differential effects across participants. This seemed to be influenced by factors such as severity of anomia, order of treatment presentation, and capacity limits. Clinical implications of these findings highlight the importance of expanding our picture of a participant’s behaviours to consider what other important factors can inform intervention decisions.
Article
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Speech production impairment is a frequent deficit observed in aphasic patients and rehabilitation programs have been extensively developed. Nevertheless, there is still no agreement on the type of rehabilitation that yields the most successful outcomes. Here, we ran a detailed meta-analysis of 39 studies of word production rehabilitation involving 124 patients. We used a model-driven approach for analyzing each rehabilitation task by identifying which levels of our model each task tapped into. We found that (1) all rehabilitation tasks are not equally efficient and the most efficient ones involved the activation of the two levels of the word production system: the phonological output lexicon and the phonological output, and (2) the activation of the speech perception system as it occurs in many tasks used in rehabilitation is not successful in rehabilitating word production. In this meta-analysis, the effect of the activation of the phonological output lexicon and the phonological output cannot be assessed separately. We further conducted a rehabilitation study with DPI, a patient who suffers from a damage of the phonological output lexicon. Our results confirm that rehabilitation is more efficient, in terms of time and performance, when specifically addressing the impaired level of word production.
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The present study describes the development and validation of two parallel picture-naming tests (PPNTs) as neuropsychological tools for evaluating word retrieval disorders in Farsi-speaking adults with and without aphasia. The development phase used the distributions of psycholinguistic variables (word frequency or age of acquisition) to select test items. Each parallel test consists of 109 line-drawings assigned to concrete nouns that were arranged in order of increasing difficulty. Assessment of content validity indicated that all items were quite or highly relevant and clear. The psychometric features were tested on 30 normal adults and 10 matched individuals with aphasia. The results showed appropriate criterion validity. Parallel tests allowed discrimination by subjects with and without naming difficulties. The tests were internally consistent. Each test form showed reasonable test-retest reliability. The correlation between the scores from both test forms indicated good parallel reliability. The cut-off point at which the tests reached the highest level of sensitivity and specificity was observed to be 86 correct responses. The percentage of correct responses for each item correlated strongly with frequency, age of acquisition, and name agreement. The overall findings support the validity and reliability of the PPNTs and suggest that these tests are appropriate for use in research and for clinical purposes. 2016
Article
Background: In the cognitive neurolinguistic approach to lexical deficits in aphasia, impaired levels of processing are localised in a cognitive model. Model-oriented treatment may target these impaired components. Thus a precise assessment of the disorder is crucial. Connectionist models add to this by using computer simulation to specify the details of the functioning of these components. The connectionist semantic-phonological model of lexical access (Dell, Martin, & Schwartz, 200715. Dell , G. S. , Martin , N. and Schwartz , M. F. 2007. A case-series test of the interactive two-step model of lexical access: Predicting word repetition from picture naming. Journal of Memory and Language, 56: 490–520. [CrossRef], [PubMed], [Web of Science ®]View all references; Schwartz, Dell, Martin, Gahl, & Sobel, 200659. Schwartz , M. F. , Dell , G. S. , Martin , N. , Gahl , S. and Sobel , P. 2006. A case-series test of the interactive two-step model of lexical access: Evidence from picture naming. Journal of Memory and Language, 54: 223–264. View all references) explores the impairment by simulating error patterns in naming and repetition.
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The aim of the study was to compare approaches highlighting either semantic or phonological features to treat naming deficits in aphasia. Treatment focused on improving picture naming. An alternating treatments design was used with a multiple baseline design across stimuli to examine effects of both approaches in two participants with varying degrees of anomia. The features approaches were modified in that three, rather than six, features were used. Significant differential effects were found across participants; this appeared to be a function of each participant's strengths or preferences over the course of treatment. Modest generalization effects were obtained for one participant. Naming error analyses revealed patterns suggestive of increased lexical access for both participants. These findings provide evidence that using a modified features-based protocol can improve naming when incorporating both semantic and phonological feature cues. Naming error patterns can provide additional evidence of improved naming during treatment.
Article
Full-text available
Speech production impairment is a frequent deficit observed in aphasic patients and rehabilitation programs have been extensively developed. Nevertheless, there is still no agreement on the type of rehabilitation that yields the most successful outcomes. Here, we ran a detailed meta-analysis of 39 studies of word production rehabilitation involving 124 patients. We used a model-driven approach for analyzing each rehabilitation task by identifying which levels of our model each task tapped into. We found that (1) all rehabilitation tasks are not equally efficient and the most efficient ones involved the activation of the two levels of the word production system: the phonological output lexicon and the phonological output, and (2) the activation of the speech perception system as it occurs in many tasks used in rehabilitation is not successful in rehabilitating word production. In this meta-analysis, the effect of the activation of the phonological output lexicon and the phonological output cannot be assessed separately. We further conducted a rehabilitation study with DPI, a patient who suffers from a damage of the phonological output lexicon. Our results confirm that rehabilitation is more efficient, in terms of time and performance, when specifically addressing the impaired level of word production.
Article
Aphasia after middle cerebral artery (MCA) stroke shows highly variable degrees of recovery. One possible explanation may be offered by the variability of the occlusion location. Branches from the proximal portion of the MCA often supply the mesial temporal lobe including parts of the hippocampus, a structure known to be involved in language learning. Therefore, we assessed whether language recovery in chronic aphasia is dependent on the proximity of the MCA infarct and correlated with the integrity of the hippocampus and its surrounding white matter. Language reacquisition capability was determined after 2weeks of intensive language therapy and 8months after treatment in ten chronic aphasia patients. Proximity of MCA occlusion relative to the internal carotid artery was determined by magnetic resonance imaging (MRI) based on the most proximal anatomical region infarcted. Structural damage to the hippocampus was assessed by MRI-based volumetry, regional microstructural integrity of hippocampus adjacent white matter by fractional anisotropy. Language learning success for trained materials was correlated with the proximity of MCA occlusion, microstructural integrity of the left hippocampus and its surrounding white matter, but not with lesion size, overall microstructural brain integrity and a control region outside of the MCA territory. No correlations were found for untrained language materials, underlining the specificity of our results for training-induced recovery. Our results suggest that intensive language therapy success in chronic aphasia after MCA stroke is critically dependent on damage to the hippocampus and its surrounding structures.
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Presents a standardized set of 260 pictures for use in experiments investigating differences and similarities in the processing of pictures and words. The pictures are black-and-white line drawings executed according to a set of rules that provide consistency of pictorial representation. They have been standardized on 4 variables of central relevance to memory and cognitive processing: name agreement, image agreement, familiarity, and visual complexity. The intercorrelations among the 4 measures were low, suggesting that they are indices of different attributes of the pictures. The concepts were selected to provide exemplars from several widely studied semantic categories. Sources of naming variance, and mean familiarity and complexity of the exemplars, differed significantly across the set of categories investigated. The potential significance of each of the normative variables to a number of semantic and episodic memory tasks is discussed. (34 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).
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The effects of self-selected semantic cues on naming performance of three individuals with aphasia were studied. Using a single-subject multiple-baseline design, a procedure incorporating semantic feature analysis was used to facilitate generalization. Two subjects showed improved naming performance on trained items, with robust generalization to untrained items and maintenance over a one-week period. Performance remained stable on a control measure of productive morphology throughout training, indicating that improved naming performance was not due to generalized language improvement. The third subject did not show substantial improvement. For the two subjects who improved, results suggest that they learned a semantic cueing strategy and applied it to both trained and untrained items for improved naming performance.
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The notion that difficult initial retrieval facilitates subsequent recall was tested in a situation similar to Brown and McNeill's (1966) tip-of-the-tongue (TOT) paradigm. After 50 trials, Ss were unexpectedly asked to recall all the target words. It was found that words retrieved with difficulty in the definition session were relatively well recalled in the final test. Further analyses revealed that the critical factor for good recall was the presence of a TOT state, or a strong feeling of knowing the word, during initial retrieval. An explanation in terms of activation of the word's attributes was suggested.
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There are various ways in which cues can be faded. The method of vanishing cues is just one option. It is argued that, when selecting a method, we should choose one that will encourage effortful recall on the training trials, but at the same time avoid too many errors and omissions. To achieve this end, we must take into account the circumstances of application, including the difficulty of the item to be learnt and the memory abilities of the learner. More difficult items and poorer memoriesmay require more gradual fading to avoid an excess of errors and omissions; easier items and better memories may require more rapid fading to encourage effortful recall. To test this prediction, two methods of fading were compared in teaching general knowledge items to 12 individualswith a history of head injury. Consistent with the prediction, Increasing Assistance (that permits more rapid fading) was more effective for those with better memories and for easier items, and Decreasing Assistance (in which fading is more gradual) was more effective for those with poorer memories and more difficult items.
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A series of four experiments are described investigating the effects of a number of treatments on the ability of aphasic patients to retrieve picture names, at some time after the treatment is applied. Auditory word-to-picture matching, visual word-to-picture matching and semantic judgements are found to have effects lasting for up to 24 hours. It is argued that durable facilitation of aphasic word retrieval is a consequence of treatment techniques that require the patients to access the semantic representation corresponding to the picture name, and this is contrasted with the short-term effects of techniques that provide patients with information about the phonological shape of the name. The theoretical and therapeutic implications of these results are discussed.
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A phonologically based treatment was implemented to train oral picture naming in four aphasic subjects with severe word-retrieval deficits. An initial assessment based on current cognitive neuropsychological models of naming indicated different levels of phonological and/or semantic deficits underlying naming failure across the subjects. Using a single-subject multiple baseline design across behaviours and subjects, the effects of treatment were evaluated by daily probing of both trained and untrained items across lexical tasks: oral naming, oral reading, and written naming. Results indicated successful acquisition of trained naming targets for the four subjects, and varied patterns of response generalization to naming of untrained phonologically and semantically related pictures, and to oral reading and written naming for the same words. Baseline levels of oral reading performance were noted to predict success in oral naming treatment. Differences in generalization patterns across tasks are discussed with regard to the varying functional levels of breakdown noted across subjects. This investigation demonstrates the utility of cognitive models in guiding the development of appropriate treatment strategies and generalization measures, and the importance of incorporating single-subject experimental designs in documenting changes associated with treatment.
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An interactive 2-step theory of lexical retrieval was applied to the picture-naming error patterns of aphasic and nonaphasic speakers. The theory uses spreading activation in a lexical network to accomplish the mapping between the conceptual representation of an object and the phonological form of the word naming the object. A model developed from the theory was parameterized to fit normal error patterns. It was then "lesioned" by globally altering its connection weight, decay rates, or both to provide fits to the error patterns of 21 fluent aphasic patients. These fits were then used to derive predictions about the influence of syntactic categories on patient errors, the effect of phonology on semantic errors, error patterns after recovery, and patient performance on a single-word repetition task. The predictions were confirmed. It is argued that simple quantitative alterations to a normal processing model can explain much of the variety among patient patterns in naming. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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Background: Impairments of word retrieval and production are a common and distressing feature of aphasia, and much clinical time is devoted to attempts at their remediation. There are now many research papers devoted to case studies examining treatments for word-retrieval impairments using a wide range of tasks with individuals who have varying levels of impairment. Aims: This paper aims to continue the selective review of this literature carried out by Nickels and Best (1996a). It summarises in table form those published papers since 1980 which present single case studies of treatment for word-retrieval impairments and which satisfy minimal methodological criteria. Main Contribution: Several main themes are derived from the literature and discussed in more detail, these include strategic approaches and facilitative or repair approaches to remediation, the contrast between semantic and phonological tasks in therapy, generalisation in therapy tasks and the relationship between impairment, therapy task, and outcome. Further discussion relates to the relationship between impairment level treatments, and measures of disability and handicap, and between therapy research and therapy practice. Conclusions: There are now many research papers devoted to impairments of word retrieval, and there can be no doubt that therapy for word-retrieval impairments can be highly successful, resulting in long-term improvements which can be of great communicative significance for the individual with aphasia. However, predicting the precise result of a specific treatment task with a specific individual with certainty is still not possible. For clinicians the recommendation is to use analyses of functional impairments to guide the choice of task, but to ensure that efficacy is tested and not assumed. Furthermore, structured multi-modal and multicomponent tasks (e.g., ''semantic'' or ''phonological'' cueing hierarchies) may hold the most promise for many individuals. For researchers, there remains a need to further dissect tasks, impairments, and their interactions across series of single cases..a u Thanks to all the contributing authors who have worked so hard to comply with my demands, and also to the reviewers of their papers. Thanks to Chris Code for inviting me to compile and edit the volume, and to Deborah Maloney and the production team at Psychology Press for their patience.
Book
In Speaking, Willem "Pim" Levelt, Director of the Max-Planck-Institut für Psycholinguistik, accomplishes the formidable task of covering the entire process of speech production, from constraints on conversational appropriateness to articulation and self-monitoring of speech. Speaking is unique in its balanced coverage of all major aspects of the production of speech, in the completeness of its treatment of the entire speech process, and in its strategy of exemplifying rather than formalizing theoretical issues. Bradford Books imprint
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This book provides both a theoretical and practical reference to cognitive neuropsychological approaches to speech and language therapists working with people with aphasia. Having evolved from the activity of a group of clinicians working with people with aphasia, it is a highly practical guide that aims to interpret the theoretical literature as it relates to aphasia and link it directly to available assessment tools and therapy techniques. The opening section of the book provides an overview of the theory underpinning the approach and how it can be applied to the assessment and interpretation of language-processing impairments. The second section offers a working explanation of different components of language processing, outlining the deficits that may arise from impairment to each component. In addition, the clinician is guided to available assessments to test out clinical hypotheses and offered interpretations of performance patterns. The final section provides a comprehensive overview of the therapy literature with systematic summaries of the therapies undertaken and a synthesis of the findings to date. This book has been written by clinicians with hands-on experience. It will be an invaluable resource for clinicians and students of speech and language therapy and related disciplines.
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Our experience with aphasia therapy has developed in the Neurology Department of the Technical University in Aachen under the direction of Klaus Poeck. Aphasia therapy is provided for both in- and outpatients. Inpatients stay either on acute wards, including intensive care, or on a special aphasia ward. Outpatients are seen either for extensive neurolinguistic and neuropsychological diagnosis at the neurological clinic or for aphasia therapy administered at the school of logopedics. The aphasia therapists cooperate with an interdisciplinary group of researchers including linguists, psychologists, and neurologists. Research on therapy has developed from clinical, diagnostic, and theoretical interests. In the past, we have made several attempts to combine different approaches to a comprehensive treatment regimen (cf. Huber, 1988; Huber, 1991, 1992; Huber, Poeck, & Springer, 1991; Huber & Springer, 1989; Poeck, 1982; Poeck, Huber, Stachowiak, & Weniger, 1977; Springer, 1986; Springer & Weniger, 1980; Weniger,Huber, Stachowiak, & Poeck, 1980; Weniger & Springer, 1989). Furthermore, we have been concerned with methodological issues of therapy research using either single case or group designs (Willmes, 1985, 1990).
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The effects of two cueing treatments for lexical retrieval were examined with three aphasic speakers who demonstrated different levels of lexical processing impairment (i.e., predominately semantic, predominately phonologic, and mixed semantic-phonologic). Each speaker received both treatments, with treatments being applied sequentially to different word lists in a multiple baseline design. Both treatments consisted of a prestimulation phase followed by the application of a response-contingent cueing hierarchy. One treatment employed semantic-level cueing, whereas the other treatment utilised phonologic-level cueing. All participants evidenced a positive response to both of the treatments and one participant (predominately phonologic-level deficit) showed a superior response to lexicalsemantic treatment.
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In this paper we discuss some aspects of the role of theory in cognitive neuropsychological research. We will consider, in particular, the nature of performance criteria used in classifying patients with acquired cognitive disorders, and we will argue that all such criteria are necessarily theory-laden. This issue will be discussed in the specific context of the putative distinction between patients with access vs. storage deficits (Warrington & Shallice, 1979). We will conclude that although the theoretical distinction between access and storage is potentially an exciting and useful one, the phononema that have been reported are far from compelling. Furthermore, and more importantly, we will argue that the proposal is not supra-theoretical in scope as has been claimed, but rather that its evaluation and verification rely crucially in the theoretical framework within which it is presented.
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Background : Traditional cognitive neuropsychological models are good at diagnosing deficits but are limited when it comes to studying recovery and rehabilitation. Parallel distributed processing (PDP) models have more potential in this regard as they are dynamic and can actually learn. However, to date very little work has been done in using PDP models to study recovery and rehabilitation. Aims : This study seeks to demonstrate how a PDP model of acquired dyslexia can be extended to provide a computational framework that is capable of making predictions about the relative effectiveness of therapeutic interventions. Methods & Procedures : A replication of Plaut, McClelland, Seidenberg, and Patterson's (1996, simulation 2) model of word reading was trained and then damaged. This damaged network was then retrained in a number of different ways designed to model both natural (spontaneous) recovery and recovery that can be attributed to a specific therapeutic intervention. Outcomes & Results : Interventions that used regular words were more effective than interventions based on inconsistent words. Early intervention (during the period of spontaneous recovery) was more effective than late intervention. Conclusions : These results suggest that this technique has the potential to provide a useful input to the therapeutic arena. The potential opportunities for further work are discussed.
Article
A single case study is presented of a global aphasic patient, JM, who shows similar impairments to other patients in the literature classified as "access dysphasics": On auditory word-written word matching tasks, JM's performance is inconsistent, it declines over repetitions, and it is sensitive to presentation rate and to the semantic relatedness of distractors (Forde & Humphreys, 1995). The deleterious effects of stimulus repetition can be attributed to JM's access to semantic information becoming refractory following activation of a target word or object. This paper examines the locus of the refractoriness by comparing JM's performance on tasks requiring access to presemantic perceptual representations or to semantic information. When both words and pictures were used as stimuli, JM was unimpaired on tasks thought to tap presemantic representations, such as visual lexical decision and unusual views matching, but performance became refractory on tasks that required access to fine-grained semantic information about specific items (e.g. associative matching). In addition, we found that the refractoriness spread across modalities when the targets changed from pictures to words. We discuss the implication of these findings for understanding the underlying nature of semantic representations of words and objects, and for the access-storage distinction in neuropsychology.
Article
Analyzing and comparing characteristics of the English versus German lexicon, we were able to show that the model can also apply to German naming data. In this study we present nine German speaking aphasic patients to, for the first time, compare the predictive power of the single- versus the dual-route model of word repetition.
Article
Background: Applying a hierarchy of cues is a well-established method in therapy for aphasic naming disorders (see overview in Nickels, 2002b; and Hillis & Caramazza, 1994; Wambaugh, 2003). Usually, cues are used in the increasing direction. Giving assistance as sparsely as possible, the naming of an individual item remains effortful which enhances the chance to recall it later on. But the high opportunity to make errors may be disadvantageous. As an alternative, the method of vanishing cues (see Glisky, 1992), which was designed for treatment of memory disorders, provides as much assistance as needed, thereby helping patients to avoid errors (see Riley & Heaton, 2000). Therefore, this method complies with “errorless learning” (see Baddeley & Wilson, 1994). It is favoured when amnesic patients have to learn new information. In aphasia therapy, the errorless learning procedure may be interesting for patients with severe naming disorders because it prevents them from producing frequent errors. Aims : The purpose of this study was to compare the effectiveness of increasing and vanishing cues for aphasic patients with naming disorders in a 4-week therapy programme. As patients may differ in the underlying mechanism of impairment, we expected a different therapy effect among and within patients. Furthermore, the importance of errorless learning should increase with severity of impairment because of error opportunity. Methods & Procedures : A total of 100 line drawings were selected and split into four sets of 25 items each. The sets were assigned to four conditions: control (no training), vanishing cue, increasing cue, and both-cue condition (training with both methods). Then 20 therapy sessions were ordered according to the alternating treatments design. During treatment, the patient's attempts to name a picture were assisted by a hierarchy of oral cues given by the therapist. Treatment methods differed in order of application but not in the type of cues used. Outcomes & Results : Cueing therapy in general was effective for 8 of 10 patients. Those patients with moderate naming disorders profited less than those with severe naming disorders. Both methods differed among and within patients. However, in contrast to our prediction, we found no patient who improved only under vanishing cues but several who showed positive effects with increasing cues alone or with both, increasing and vanishing cues. Conclusions : Unlike patients with amnesia, patients with aphasia do not seem to be troubled by their errors and may not require the vanishing cue method.
Article
Background: Lexical retrieval problems are pervasive in aphasia and are often an important focus of treatment. Although many treatments have been demonstrated to positively impact lexical retrieval in aphasia, comparisons of such treatments have been relatively rare. Aims: The purpose of this investigation was to compare the relative effects of two lexical retrieval cueing treatments when administered concurrently with a participant with chronic anomic aphasia. The cueing treatments, phonological cueing treatment (PCT) and semantic cueing treatment (SCT) were designed to target the lexical phonologic and lexical semantic levels of processing, respectively. Methods & Procedures: The participant received both treatments concomitantly in the context of an alternating treatments design and multiple baseline design across behaviours. Separate lists of words were assigned to each treatment and additional word lists were designated for generalisation assessment. Following achievement of criterion levels of performance, each treatment was then applied to the additional lists in order to attempt to replicate treatment effects. Outcomes & Results: The participant showed a positive response to both treatments. However, he achieved higher levels of accuracy of naming for items treated with SCT. This effect was observed in both phases of treatment application. Conclusions: For this participant, SCT appeared to be the preferred treatment, at least in the context of concurrent administration of the treatments. This preferential response may be related to a pretreatment pattern of responding in which the participant routinely used descriptions and semantically related sentence cues to attempt to retrieve words.
Article
Background: Many therapy techniques for word retrieval disorders use some form of priming to improve access to words. Priming can facilitate or interfere with naming under different circumstances. We examined effects of priming when combined with semantic or phonological context (training words in groups that are semantically or phonologically related) and how these effects interact with the type of naming impairment (semantically or phonologically based). Aims: We addressed three questions (1) Are word retrieval impairments differentially sensitive to priming with semantic or phonological contexts? (2) Would such differences be systematically related to deficits of semantic versus phonological processing? (3) Do effects of priming evolve from immediate interference to short‐term facilitation, as predicted by an interactive activation model of word retrieval? Methods & Procedures: A total of 11 chronic English‐speaking aphasic subjects with varied types of aphasia participated in this experiment. Background measures of semantic and phonological processing ability were administered to determine the nature of each subject's naming impairment. The experiment involved one‐session facilitation treatments for each of three context conditions (semantic, phonological, and unrelated), plus three replications (nine subjects) or one replication (two subjects). Ten pictures in each condition were tested before and after treatment. Five pictures were trained and five served as controls. Participants repeated the name of each picture four times (repetition priming) and then attempted to name each picture individually (naming probe). Repetition priming and naming probes were repeated eight times. We used McNemar tests to compare rates of correct responses before and after priming, and chi square analyses of correct responses and contextual errors on naming probes obtained during the priming sessions. Outcome & results: Our predictions were borne out in the data. Participants varied in their sensitivity to the semantic and phonological contexts. The error data suggest that interference during training is more likely when the context (semantic or phonological) and underlying source of the word processing impairment (semantic or phonological) match. Additionally, we found two sequential effects of contextual priming: immediate interference followed short‐term facilitation. Conclusions: These data have theoretical implications regarding the time course of priming effects, but also have important clinical implications. The present contextual priming procedure is relatively short and could be used as a predictor of performance patterns in a long‐term treatment protocol that uses this approach or other tasks that employ priming.
Article
We investigated the effects of contextual priming on picture naming in a severely anomic patient suffering from Wernicke's aphasia. The contextual priming method attempts to facilitate impaired lexical retrieval with massive repetition priming of target names, coupled with manipulation of relationships among pictures to-be-named (semantic, phonological and unrelated). We were interested in comparing our patient's results with those of a previously reported case whose underlying mechanisms of anomia were different (Laine and Martin 1996). Both case studies show similar contextual effects on naming error patterns, confirming that the present method has the potential of activating multiple lexical entries in aphasics. At the same time, the two patients show different contextual effects on their rates of correct responses. In particular, only the present case is facilitated by a phonologically related context in naming. The implication for treatment studies is that it is useful to match priming treatments to the deficit that underlies word retrieval difficulty.
Article
The case of a globally aphasic patient (JCU) is reported. Four experiments are described. In the first, she was able to make correct non-verbal semantic judgements about pictures. In naming, correct phonemic cues elicited correct names for 49% of the pictures. Incorrect cues elicited a variety of errors; semantic errors were the most frequent, and they were not often rejected by JCU saying “no” immediately afterwards. Unrelated word paraphasias were usually rejected. Cued word reading was no worse than naming but there were many fewer semantic errors. In a comprehension task, JCU was able to judge that correct names were correct, and that unrelated names were inappropriate, but she judged more than 50% of semantic co-ordinates of the correct names to be correct. The nature of the processes responsible for her semantic errors is discussed, and it is argued that JCU is using incomplete semantic information in name retrieval and word comprehension, but that she does not have a deficit specific to any particular lexical items.
Article
This paper takes the form of a selective review of studies of therapy for aphasic-naming disorders. There is a bias in the literature towards studies involving the use of semantic tasks (particularly word-to-picture matching) in therapy and therefore this is reflected here. These studies provide clear evidence that aphasic naming disorders can be remediated but it remains difficult to ascertain the precise mechanism by which this improvement in naming is achieved. Several issues are discussed which pertain to this problem: the effectiveness of ‘semantic’ and ‘phonological’ tasks; the relevance of each component of the therapy task to the outcome of the therapy; the relationship between the type of deficit and the effectiveness of a task; when generalization can be expected as opposed to (treated) item-specific improvement; and the importance of patient success on the task to the success of the therapy. Finally, the paper concludes with suggestions for the possible direction of further research into this important area.
Article
Neuropsychological results are increasingly cited in cognitive theories although their methodology has been severely criticised. The book argues for an eclectic approach but particularly stresses the use of single-case studies. A range of potential artifacts exists when inferences are made from such studies to the organisation of normal function – for example, resource differences among tasks, premorbid individual differences, and reorganisation of function. The use of “strong” and “classical” dissociations minimises potential artifacts. The theoretical convergence between findings from fields where cognitive neuropsychology is well developed and those from the normal literature strongly suggests that the potential artifacts are not critical. The fields examined in detail in this respect are short-term memory, reading, writing, the organisation of input and output speech systems, and visual perception. Functional dissociation data suggest that not only are input systems organised modularly, but so are central systems. This conclusion is supported by findings on impairment of knowledge, visual attention, supervisory functions, memory, and consciousness.
Article
The results of treatment for acquired dyslexia in a patient, P.S., are presented, cognitive analysis of the patient's performance provides evidence for proposing relatively selective impairments within the reading process to the orthographic input lexicon and to one or more components of sublexical processes for converting print to sound. Results of several contrasting treatment programmes for his deficits are reported, along with results of the same treatment approaches for patients with the same «diagnosis» (i.e. proposed locus of impairment in the cognitive processes underlying reading) or with different «diagnoses». The results illustrate that the relationship between the «diagnosis» and successful treatment is not simple. Rather, the reported results indicate the following departures from a 1:1 relationship between the locus of damage and the effective intervention: (1) contrasting treatment approaches can be equally appropriate for a given locus of damage, but the approaches may affect different aspects of language performance; (2) a given treatment strategy may be successful for some patients but not for others with the same putative level of damage (although this may be because the damage can take various forms); and (3) a given treatment strategy can be equally appropriate for several different levels of damage, perhaps in part because separate components of the treatment affect different levels of processing. These illustrations then serve as the basis for discussing the types of predictions that are possible regarding the effects of particular interventions on the basis of postulating a specific locus of disruption in the reading (or other cognitive) process in the patient to be treated.
Article
This study investigated the efficacy of two types of cues (phonemic and semantic) in aphasic patients with naming deficits. Subjects consisted of ten Broca's, ten Wernicke's, eight conduction, and eight anomic aphasic subjects. Cues were administered following failure to name on confrontation. Responsiveness to cueing was dependent on type of cue and type of aphasia. Subjects performed better on phonemic as compared to semantic cues. In addition, aphasic subgroups responded differentially, with conduction subjects responding significantly better to cueing than Wernicke's subjects. These findings are discussed with respect to the neuropsychological mechanisms involved in cueing.