BACKGROUND: SentenceShaper() (SSR) is a computer program that supports spoken language production in aphasia by recording and storing the fragments that the user speaks into the microphone, making them available for playback and allowing them to be combined and integrated into larger structures (i.e., sentences and narratives). A prior study that measured utterance length and grammatical complexity in story-plot narratives produced with and without the aid of SentenceShaper demonstrated an "aided effect" in some speakers with aphasia, meaning an advantage for the narratives that were produced with the support of this communication aid (Linebarger, Schwartz, Romania, Kohn, & Stephens, 2000). The present study deviated from Linebarger et al.'s methods in key respects and again showed aided effects of SentenceShaper in persons with aphasia. AIMS: Aims were (1) to demonstrate aided effects in "functional narratives" conveying hypothetical real-life situations from a first person perspective; (2) for the first time, to submit aided and spontaneous speech samples to listener judgements of informativeness; and (3) to produce preliminary evidence on topic-specific carryover from SentenceShaper, i.e., carryover from an aided production to a subsequent unaided production on the same topic. METHODS #ENTITYSTARTX00026; PROCEDURES: Five individuals with chronic aphasia created narratives on two topics, under three conditions: Unaided (U), Aided (SSR), and Post-SSR Unaided (Post-U). The 30 samples (5 participants, 2 topics, 3 conditions) were randomised and judged for informativeness by graduate students in speech-language pathology. The method for rating was Direct Magnitude Estimation (DME). OUTCOMES #ENTITYSTARTX00026; RESULTS: Repeated measures ANOVAs were performed on DME ratings for each participant on each topic. A main effect of Condition was present for four of the five participants, on one or both topics. Planned contrasts revealed that the aided effect (SSR >U) was significant in each of these cases. For two participants, there was also topic-specific carryover (Post-U >U). CONCLUSIONS: Listeners judged functional narratives generated on SentenceShaper to be more informative than comparable narratives spoken spontaneously. This extends the evidence for aided effects of SentenceShaper. There was also evidence, albeit weaker, for topic-specific carryover, suggesting that the program might be used effectively to practise for upcoming face-to-face interactions.
Background: The significance of imageability and concreteness as factors for lexical tasks in aphasic individuals is under debate. No previous treatment studies have looked specifically at training abstract words compared to concrete for improved lexical retrieval in patients with chronic aphasia. Aims: The goal of the present study was to determine the efficacy of a treatment for lexical retrieval that is based on models of lexical processing by utilising abstractness as a mode of complexity. It was hypothesised that training abstract words in a category will result in improvement of those words and generalisation to untrained target concrete words in the same category. However, training concrete words in a category will result in the retrieval of trained concrete words, but not generalisation to target abstract words. Methods & Procedures: A single‐participant experimental design across participants and behaviours was used to examine treatment and generalisation. Generative naming for three categories (church, hospital, courthouse) was tested during baseline and treatment. Each treatment session was carried out in five steps: (1) category sorting, (2) feature selection, (3) yes/no feature questions, (4) word recall, and (5) free generative naming. Outcomes & Results: Although participant 1 demonstrated neither significant learning nor generalisation during abstract or concrete word training, participants 2, 3, and 4 showed significant learning during abstract word training and generalisation to untrained concrete words. Participants 3 and 4 were also trained on concrete words, on which they improved, but did not show generalisation to untrained abstract words. Conclusions: The results of the present experiment support our hypothesis that training abstract words would result in greater learning and generalisation to untrained concrete words. They also tentatively support the idea that generalisation is facilitated by treatment focusing on more complex constructions (Kiran & Thompson, 200318.
Kiran , S. and
Thompson , C. K. 2003. The role of semantic complexity in treatment of naming deficits: Training semantic categories in fluent aphasia by controlling exemplar typicality.. Journal of Speech, Language and Hearing Research, 46(4): 773–787. View all references; Thompson, Shapiro, Kiran, & Sobecks, 200326.
Thompson , C. K. ,
Shapiro , L. P. ,
Kiran , S. and
Sobecks , J. 2003. The role of syntactic complexity in treatment of sentence deficits in agrammatic aphasia: The complexity account of treatment efficacy (CATE).. Journal of Speech Language and Hearing Research, 46(3): 591–607. View all references).
BACKGROUND: Acquired deep dyslexia is characterized by impairment in grapheme-phoneme conversion and production of semantic errors in oral reading. Several theories have attempted to explain the production of semantic errors in deep dyslexia, some proposing that they arise from impairments in both grapheme-phoneme and lexical-semantic processing, and others proposing that such errors stem from a deficit in phonological production. Whereas both views have gained some acceptance, the limited evidence available does not clearly eliminate the possibility that semantic errors arise from a lexical-semantic input processing deficit. AIMS: To investigate semantic processing in deep dyslexia, this study examined the typicality effect in deep dyslexic individuals, phonological dyslexic individuals, and controls using an online category verification paradigm. This task requires explicit semantic access without speech production, focusing observation on semantic processing from written or spoken input. METHODS #ENTITYSTARTX00026; PROCEDURES: To examine the locus of semantic impairment, the task was administered in visual and auditory modalities with reaction time as the primary dependent measure. Nine controls, six phonological dyslexic participants, and five deep dyslexic participants completed the study. OUTCOMES #ENTITYSTARTX00026; RESULTS: Controls and phonological dyslexic participants demonstrated a typicality effect in both modalities, while deep dyslexic participants did not demonstrate a typicality effect in either modality. CONCLUSIONS: These findings suggest that deep dyslexia is associated with a semantic processing deficit. Although this does not rule out the possibility of concomitant deficits in other modules of lexical-semantic processing, this finding suggests a direction for treatment of deep dyslexia focused on semantic processing.
AIMS: The goals of the study were (a) to examine the effect of discourse type on lexical diversity by testing whether there are significant differences among language samples elicited using four discourse tasks (procedures, eventcasts, story telling, and recounts); and (b) to assess the extent to which age influences lexical diversity when different types of discourse are elicited. METHODS #ENTITYSTARTX00026; PROCEDURES: A total of 86 cognitively healthy adults participated in the study and comprised two groups - young adults (20-29 years old) and older adults (70-89 years old). Participants completed the discourse tasks and their language samples were analysed using dedicated software (voc-D) to obtain estimates of their lexical diversity. OUTCOMES #ENTITYSTARTX00026; RESULTS: A mixed 2 × 4 ANOVA was conducted and followed by an investigation of simple main effects. A lexical diversity hierarchy was established that was similar for both age groups. The study also uncovered age-related differences that were evident when the stimuli were verbally presented but were eliminated when the language samples were elicited using pictorial stimuli. CONCLUSIONS: Results indicated that lexical diversity is one of the microlinguistic indices that are influenced by discourse type and age, a finding that carries important methodological implications. Future investigations are warranted to explore the patterns of lexical diversity in individuals with neurogenic language disorders and assess the clinical utility of measures of lexical diversity.
BACKGROUND: Patients with amnesia may have more than pure memory deficits, as evidenced by reports of subtle linguistic impairments on formal laboratory tasks in the amnesic patient HM. However, little attention has been given to the impact of memory impairments on language use in regular, colloquial interactions. We analysed reported speech use by individuals with amnesia. Reported speech (RS), in which speakers represent thoughts/words from another time and/or place, requires management of two temporal frames, making it an interesting discourse practice in which to explore the impact of memory deficits on interactional aspects of communication. AIMS: This study: (1) documents frequency, type, and temporal contexts of reported speech used in discourse samples; (2) compares reported speech use by amnesic and comparison participants; (3) examines the interactional character of reported speech use in these discourse samples. METHODS AND PROCEDURES: Derived from a broader study of the discourse practices of individuals with amnesia, this study uses quantitative group comparisons and close discourse analysis to analyse reported speech episodes (RSEs) in interactional discourse samples between a clinician and each of 18 participants, 9 individuals with amnesia and 9 comparison participants (NC). OUTCOMES AND RESULTS: Reported speech was used by all participants. However, significantly fewer RSEs were produced in amnesia sessions (273) than in NC sessions (554). No significant group differences were observed for type or temporal domain. In addition, for the participants with amnesia, post-amnesia past RSEs differed qualitatively from the other RSEs in the data. CONCLUSIONS: These findings have important implications for understanding the interdependent relationship of memory and language, point to the value of examining interactional aspects of communication in the empirical study of brain-behaviour relationships, and reconceptualise interaction as a target in the remediation of functional communication following brain injury.
Background: Differences in lexical diversity (LD) across different discourse elicitation tasks have been found in neurologically intact adults (NIA) (Fergadiotis, Wright, & Capilouto, 2010) but have not been investigated systematically in people with aphasia (PWA). Measuring lexical diversity in PWA may serve as a useful clinical tool for evaluating the impact of word retrieval difficulties at the discourse level. Aims: The study aims were (a) to explore the differences between the oral language samples of PWA and NIA in terms of LD as measured by dedicated computer software (voc-D), (b) to determine whether PWA are sensitive to discourse elicitation task in terms of LD, and (c) to identify whether differences between PWA and NIA vary in magnitude as a function of discourse task. Method & Procedures: Oral language samples from 25 PWA and 27 NIA were analysed. Participants completed three commonly used discourse elicitation tasks (single pictures, sequential pictures, story telling) and voc-D was used to obtain estimates of their LD. Outcomes & Results: A mixed 2 x 3 ANOVA revealed a significant group x task interaction that was followed by an investigation of simple main effects and tetrad comparisons. Different patterns of LD were uncovered for each group. For the NIA group results were consistent with previous findings in the literature according to which LD varies as a function of elicitation technique. However, for PWA sequential pictures and story telling elicited comparable estimates of LD. Conclusions: Results indicated that LD is one of the microlinguistic indices that are influenced by elicitation task and the presence of aphasia. These findings have important implications for modelling lexical diversity and selecting and interpreting results from different discourse elicitation tasks.
The neural basis of action understanding is a hotly debated issue. The mirror neuron account holds that motor simulation in fronto-parietal circuits is critical to action understanding including speech comprehension, while others emphasize the ventral stream in the temporal lobe. Evidence from speech strongly supports the ventral stream account, but on the other hand, evidence from manual gesture comprehension (e.g., in limb apraxia) has led to contradictory findings.
Here we present a lesion analysis of sign language comprehension. Sign language is an excellent model for studying mirror system function in that it bridges the gap between the visual-manual system in which mirror neurons are best characterized and language systems which have represented a theoretical target of mirror neuron research.
Twenty-one life long deaf signers with focal cortical lesions performed two tasks: one involving the comprehension of individual signs and the other involving comprehension of signed sentences (commands). Participants' lesions, as indicated on MRI or CT scans, were mapped onto a template brain to explore the relationship between lesion location and sign comprehension measures.
Single sign comprehension was not significantly affected by left hemisphere damage. Sentence sign comprehension impairments were associated with left temporal-parietal damage. We found that damage to mirror system related regions in the left frontal lobe were not associated with deficits on either of these comprehension tasks.
We conclude that the mirror system is not critically involved in action understanding.
BACKGROUND: Neurophysiological evidence from primates has demonstrated the presence of mirror neurons, with visual and motor properties, that discharge both when an action is performed and during observation of the same action. A similar system for observation-execution matching may also exist in humans. We postulate that behavioral stimulation of this parietal-frontal system may play an important role in motor learning for speech and thereby aid language recovery after stroke. AIMS: The purpose of this article is to describe the development of IMITATE, a computer-assisted system for aphasia therapy based on action observation and imitation. We also describe briefly the randomized controlled clinical trial that is currently underway to evaluate its efficacy and mechanism of action. METHODS AND PROCEDURES: IMITATE therapy consists of silent observation of audio-visually presented words and phrases spoken aloud by six different speakers, followed by a period during which the participant orally repeats the stimuli. We describe the rationale for the therapeutic features, stimulus selection, and delineation of treatment levels. The clinical trial is a randomized single blind controlled trial in which participants receive two pre-treatment baseline assessments, six weeks apart, followed by either IMITATE or a control therapy. Both treatments are provided intensively (90 minutes per day). Treatment is followed by a post-treatment assessment, and a six-week follow-up assessment. OUTCOMES #ENTITYSTARTX00026; RESULTS: Thus far, five participants have completed IMITATE. We expect the results of the randomized controlled trial to be available by late 2010. CONCLUSIONS: IMITATE is a novel computer-assisted treatment for aphasia that is supported by theoretical rationales and previous human and primate data from neurobiology. The treatment is feasible, and preliminary behavioral data are emerging. However, the results will not be known until the clinical trial data are available to evaluate fully the efficacy of IMITATE and to inform theoretically about the mechanism of action and the role of a human mirror system in aphasia treatment.
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; Martin & Saffran, 1999; Trojano & Grossi, 1995). 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). 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 #ENTITYSTARTX00026; 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).
BACKGROUND: The right cerebral hemisphere (RH) sustains activation of subordinate, secondary, less common, and/or distantly related meanings of words. Much of the pertinent data come from studies of homonyms, but some evidence also suggests that the RH has a unique maintenance function in relation to unambiguous nouns. In a divided visual field priming study, Atchley, Burgess, and Keeney (1999) reported that only left visual field/RH presentation yielded evidence of continuing activation of peripheral semantic features that were incompatible with the most common image or representation of their corresponding nouns (e.g., rotten for "apple"). Activation for weakly related features that were compatible with the dominant representation (e.g., crunchy) was sustained over time regardless of the visual field/hemisphere of initial stimulus input. Several studies report that unilateral right hemisphere brain damage (RHD) in adults affects the RH's meaning maintenance function, but this work also has centred on homonyms, and/or more recently metonymic and metaphoric polysemous words. AIMS: The current investigation examined whether RHD deficits in processing secondary and/or distantly related meanings of words, typically observed in studies of homonyms, would extend to peripheral, weakly related semantic features of unambiguous nouns. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants were 28 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Participants listened to spoken sentences that ended with an unambiguous noun. Each sentence was followed by a spoken target phoneme string. Targets included peripheral semantic features of the sentence-final noun that were either compatible or incompatible with the dominant mental images of the noun, and were presented at two intervals after that noun. A lexical decision task was used to gauge both the early activation and maintenance of activation for these weakly related semantic features. OUTCOMES #ENTITYSTARTX00026; RESULTS: Accuracy data demonstrated activation (priming) for both types of peripheral features, in both groups, shortly after presentation of the corresponding noun. Neither group evidenced continuing activation for either type of feature at a longer interval. These results are interpreted as reflecting rapid decay/poor maintenance of activation for distantly related features for both groups. The lack of a biasing context, however, did not provide an appropriate test for previously reported suppression deficits after RHD. Fast decay of activation of compatible semantic features was unexpected for the control group. Adults with RHD were less accurate than the control group at both test intervals for the features that are semantically more distant from their associated nouns (Related-incompatible features). Accordingly, it is argued that the RHD group's poor maintenance of activation for these features reflects a deficit, rather than normal performance. The interpretation of results from this study is complicated by the lack of RT priming for either type of semantic feature, and for either participant group. CONCLUSIONS: The right cerebral hemisphere appears to be necessary for activating semantic features that are particularly distantly related to their corresponding lexical items, and for sustaining activation of these features in the absence of a biasing context. Because lexical processing has been linked with discourse comprehension for adults with RHD, more work in this area should enhance clinical management in the future.
BACKGROUND: Previous research using functional MRI (fMRI) suggests changes in cortical activation as a function of increased task difficulty. This relationship has not been explored in persons with aphasia even though it may have significant implications for pre- and post-treatment interpretation of fMRI data. AIMS: The purpose of this exploratory study was to investigate the relationship between changes in language task difficulty and cortical activation in persons with aphasia. METHODS #ENTITYSTARTX00026; PROCEDURES: Four persons with chronic anomic or Broca's aphasia and four matched control participants underwent fMRI while performing a picture-word matching task. OUTCOMES #ENTITYSTARTX00026; RESULTS: Compared to the more difficult task condition, all participants performed with greater accuracy on the easier condition. Moreover, greater mean blood oxygenated level dependent (BOLD) signal intensity and area recruitment were noted during the more difficult condition for three out of four persons with aphasia as well as three of the four controls. The increase in cortical activity was mainly noted in the superior temporal and posterior inferior frontal lobes. CONCLUSIONS: The present findings mirror those found in previous studies of normal subjects in that cortical activation increased in parallel to task difficulty for most of our participants. It is unclear what mechanism accounts for this effect; this phenomenon might need to be considered in future fMRI studies of neural plasticity associated with aphasia treatment.
Background: A recent review of interaction (or conversation)-focused therapy highlighted the potential of programmes targeting the person with aphasia (PWA) directly. However, it noted the key limitations of current work in this field to be a reliance on single case analyses and qualitative evidence of change, a situation that is not unusual when a complex behavioural intervention is in the early stages of development and evaluation.
Aims: This article aims to evaluate an intervention that targeted a PWA and their conversation partner (CP), a dyad, as equals in a novel conversation therapy for agrammatic aphasia, using both quantitative and qualitative evidence of change. The intervention aimed to increase the insight of a dyad into facilitator and barrier conversation behaviours, to increase the understanding of the effect of agrammatism on communication, and to support each speaker to choose three strategies to work on in therapy to increase mutual understanding and enhance conversation.
Methods & Procedures: Quantitative and qualitative methods are used to analyse multiple pre-therapy and follow up assessments of conversation for two dyads.
Outcomes & Results: Results show that one person with severe and chronic agrammatic aphasia was able to select and practise strategies that led to qualitative and quantitative changes in his post-therapy conversations. The other PWA showed a numerical increase in one of his three strategies post therapy, but no significant quantitative change. Although both CPs significantly reduced barrier behaviours in their post-therapy conversations, neither showed a significant increase in the strategies they chose to work on. For one CP, there was qualitative evidence of the use of different turn types.
Conclusions: Individually tailored input from a speech and language therapist can assist some people with chronic agrammatism to develop conversational strategies that enhance communication. Outcomes are influenced by the severity and extent of language deficits affecting, for example, single word writing. In terms of behaviour change for CPs, it appears that it may be easier to reduce barrier behaviours rather than to increase the use of facilitatory strategies. The results have implications for collaborative goal setting with clients undergoing conversation therapy.
BACKGROUND: Discourse is a naturally occurring, dynamic form of communication. Coherence is one aspect of discourse and is a reflection of the listener's ability to interpret the overall meaning conveyed by the speaker. Adults with aphasia may present with impaired maintenance of global coherence, which, in turn, may contribute to their difficulties in overall communicative competence. AIMS: The aim of the study was to determine if microlinguistic processes contribute to maintenance of global coherence in adults with and without aphasia. METHOD AND PROCEDURES: Participants included 15 adults with aphasia (PWA) and 15 healthy controls (HC). Study participants told stories conveyed in wordless picture books. The discourse samples were transcribed and then analyzed for percent of information units produced, lexical diversity, syntactic complexity, and maintenance of global coherence. OUTCOMES AND RESULTS: Several linear regression models were carried out to investigate the relationship among the microlinguistic and macrolinguistic measures. For the control group, percent of information units conveyed was a significant predictor of maintenance of global coherence for stories told. For the aphasia group, percent of information units conveyed and lexical diversity were significant predictors of maintenance of global coherence for stories told. CONCLUSIONS: Results indicated that microlinguistic processes contribute to the maintenance of global coherence in stories told by adults with aphasia. These findings have important clinical implications for using a multi-level discourse model for analyzing discourse ability in adults with aphasia and measuring individual response to treatment.
Background: For decades researchers assumed visual image generation was the province of the right hemisphere. The lack of corresponding evidence was only recently noted, yet conflicting results still leave open the possibility that the right hemisphere plays a role. This study assessed imagery generation in adult participants with and without right hemisphere damage (RHD). Imagery was operationalised as the activation of representations retrieved from long‐term memory similar to those that underlie sensory experience, in the absence of the usual sensory stimulation, and in the presence of communicative stimuli. Aims: The primary aim of the study was to explore the widely held belief that there is an association between the right hemisphere and imagery generation ability. We also investigated whether visual and visuo‐motor imagery generation abilities differ in adults with RHD. Methods & Procedures: Participants included 34 adults with unilateral RHD due to cerebrovascular accident and 38 adults who served as non‐brain‐damaged (NBD) controls. To assess the potential effects of RHD on the processing of language stimuli that differ in imageability, participants performed an auditory sentence verification task. Participants listened to high‐ and low‐imageability sentences from Eddy and Glass (19818.
Eddy , J. K. and
Glass , A. L. 1981. Reading and listening to high and low imagery sentences.. Journal of Verbal Learning and Verbal Behavior, 20: 333–345. [CrossRef]View all references) and indicated whether each sentence was true or false. The dependent measures for this task were performance accuracy and response times (RT). Outcomes & Results: In general, accuracy was higher, and response time lower, for low‐imagery than for high‐imagery items. Although NBD participants' RTs for low‐imagery items were significantly faster than those for high‐imagery items, this difference disappeared in the group with RHD. We confirmed that this result was not due to a speed–accuracy trade‐off or to syntactic differences between stimulus sets. A post hoc analysis also suggested that the group with RHD was selectively impaired in motor, rather than visual, imagery generation. Conclusions: The disproportionately high RT of participants with RHD in response to low‐imagery items suggests that these items had other properties that made their verification difficult for this population. The nature and extent of right hemisphere patients' deficits in processing different types of imagery should be considered. In addition, the capacity of adults with RHD to generate visual and motor imagery should be investigated separately in future studies.
BACKGROUND: Adults with right hemisphere brain damage (RHD) can have considerable difficulty in drawing high-level inferences from discourse. Standardised tests of language comprehension in RHD do not tap high-level inferences with many items or in much depth, but nonstandardised tasks lack reliability and validity data. It would be of great clinical value if a standardised test could predict performance on high-level inferencing measures. AIMS: This study addressed whether performance of adults with RHD on the Discourse Comprehension Test (DCT; Brookshire & Nicholas, 1993) could predict their performance on a nonstandardised measure of high-level inference in narrative comprehension. METHODS #ENTITYSTARTX00026; PROCEDURES: This study used a within-group correlational design. Participants were 32 adults with damage limited to the right cerebral hemisphere, as a result of cerebrovascular accident. Half of the participants were male and half female. Participants averaged 64.5 years of age and 14.2 years of education. Participants listened to narrative stimuli and to yes/no questions about each narrative. Each DCT narrative was followed by the standard 8 questions about stated or implied main ideas or details. The high-level inferencing task contained 6 narrative scenarios from Winner, Brownell, Happé, Blum, and Pincus (1998). Each scenario describes a character who commits a minor transgression and later denies it. Two versions of each story are designed to induce different interpretations of the character's denial. In one version, the character tells a white lie when he is unaware that he was seen committing the transgression. In the other versions, when aware of being seen, the character makes an ironic joke. The narratives were interrupted periodically by comprehension questions. Four Pearson correlation coefficients were computed, between each of two DCT predictor variables (total accuracy for all comprehension questions; accuracy on questions about implied information) and two indicators of high-level inferencing (total accuracy to answer experimental questions in Joke stories; total accuracy to answer experimental questions in Lie stories). OUTCOMES #ENTITYSTARTX00026; RESULTS: Correlation coefficients were low-to-moderate, and nonsignificant. CONCLUSIONS: Performance on the DCT by adults with RHD did not predict their high-level inferencing performance, as measured in this study. The issue that motivated this study should be pursued further in light of the potential advantages to be gained, for both clinical and research purposes. It may be, however, that specific measures of various types of high-level inferencing will need to be developed and validated.
BACKGROUND: Difficulties in social cognition and interaction can characterise adults with unilateral right hemisphere brain damage (RHD). Some pertinent evidence involves their apparently poor reasoning from a "Theory of Mind" perspective, which requires a capacity to attribute thoughts, beliefs, and intentions in order to understand other people's behaviour. Theory of Mind is typically assessed with tasks that induce conflicting mental representations. Prior research with a commonly used text task reported that adults with RHD were less accurate in drawing causal inferences about mental states than at making non-mental-state causal inferences from control texts. However, the Theory of Mind and control texts differed in the number and nature of competing discourse entity representations. This stimulus discrepancy, together with the explicit measure of causal inferencing, likely put the adults with RHD at a disadvantage on the Theory of Mind texts. AIMS: This study revisited the question of Theory of Mind deficit in adults with RHD. The aforementioned Theory of Mind texts were used but new control texts were written to address stimulus discrepancies, and causal inferencing was assessed relatively implicitly. Adults with RHD were hypothesised not to display a Theory of Mind deficit under these conditions. METHODS #ENTITYSTARTX00026; PROCEDURES: The participants were 22 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Participants listened to spoken texts that targeted either mental-state or non-mental-state causal inferences. Each text was followed by spoken True/False probe sentences, to gauge target inference comprehension. Both accuracy and RT data were recorded. Data were analysed with mixed, two-way Analyses of Variance (Group by Text Type). OUTCOMES #ENTITYSTARTX00026; RESULTS: There was a main effect of Text Type in both accuracy and RT analyses, with a performance advantage for the Theory of Mind/mental-state inference stimuli. The control group was faster at responding, and primed more for the target inferences, than the RHD group. The overall advantage for Theory of Mind texts was traceable to one highly conventional inference: someone tells a white lie to be polite. Particularly poor performance in mental-state causal inferencing was not related to neglect or lesion site for the group with RHD. CONCLUSIONS: With appropriate stimulus controls and a relatively implicit measure of causal inferencing, this study found no "Theory of Mind" deficit for adults with RHD. The utility of the "Theory of Mind" construct is questioned. A better understanding of the social communication difficulties of adults with RHD will enhance clinical management in the future.
BACKGROUND: Various investigators suggest that some discourse-level comprehension difficulties in adults with right hemisphere brain damage (RHD) have a lexical-semantic basis. As words are processed, the intact right hemisphere arouses and sustains activation of a wide-ranging network of secondary or peripheral meanings and features-a phenomenon dubbed "coarse coding". Coarse coding impairment has been postulated to underpin some prototypical RHD comprehension deficits, such as difficulties with nonliteral language interpretation, discourse integration, some kinds of inference generation, and recovery when a reinterpretation is needed. To date, however, no studies have addressed the hypothesised link between coarse coding deficit and discourse comprehension in RHD. AIMS: The current investigation examined whether coarse coding was related to performance on two measures of narrative comprehension in adults with RHD. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants were 32 adults with unilateral RHD from cerebrovascular accident, and 38 adults without brain damage. Coarse coding was operationalised as poor activation of peripheral/weakly related semantic features of words. For the coarse coding assessment, participants listened to spoken sentences that ended in a concrete noun. Each sentence was followed by a spoken target phoneme string. Targets were subordinate semantic features of the sentence-final nouns that were incompatible with their dominant mental representations (e.g., "rotten" for apple). Targets were presented at two post-noun intervals. A lexical decision task was used to gauge both early activation and maintenance of activation of these weakly related semantic features. One of the narrative tasks assessed comprehension of implied main ideas and details, while the other indexed high-level inferencing and integration. Both comprehension tasks were presented auditorily. For all tasks, accuracy of performance was the dependent measure. Correlations were computed within the RHD group between both the early and late coarse coding measures and the two discourse measures. Additionally, ANCOVA and independent t-tests were used to compare both early and sustained coarse coding in subgroups of good and poor RHD comprehenders. OUTCOMES #ENTITYSTARTX00026; RESULTS: The group with RHD was less accurate than the control group on all measures. The finding of coarse coding impairment (difficulty activating/sustaining activation of a word's peripheral features) may appear to contradict prior evidence of RHD suppression deficit (prolonged activation for context-inappropriate meanings of words). However, the sentence contexts in this study were unbiased and thus did not provide an appropriate test of suppression function. Correlations between coarse coding and the discourse measures were small and nonsignificant. There were no differences in coarse coding between RHD comprehension subgroups on the high-level inferencing task. There was also no distinction in early coarse coding for subgroups based on comprehension of implied main ideas and details. But for these same subgroups, there was a difference in sustained coarse coding. Poorer RHD comprehenders of implied information from discourse were also poorer at maintaining activation for semantically distant features of concrete nouns. CONCLUSIONS: This study provides evidence of a variant of the postulated link between coarse coding and discourse comprehension in RHD. Specifically, adults with RHD who were particularly poor at sustaining activation for peripheral semantic features of nouns were also relatively poor comprehenders of implied information from narratives.
Studies of sentence comprehension in non-disordered populations have convincingly demonstrated that probabilistic cues influence on-line syntactic processing. One well-studied cue is verb argument structure bias, which refers to the probability that a verb will occur in a particular syntactic frame. According to the Lexical Bias Hypothesis, people with aphasia have difficulty understanding sentences in which the verb's argument structure bias conflicts with the sentence structure (e.g., a transitively biased verb in an intransitive sentence). This hypothesis may provide an account of why people with aphasia have difficulty understanding both simple and complex sentences.
The purpose of this study was to test the Lexical Bias Hypothesis using an on-line measure of written sentence comprehension, self-paced reading.
The participants were ten people with aphasia and ten non-brain-damaged controls. The stimuli were syntactically simple transitive and intransitive sentences that contained transitively- or intransitively-biased verbs. For example, the transitively-biased verb "called" appeared in sentences such as "The agent called (the writer) from overseas to make an offer." The intransitively-biased verb "danced" appeared in sentences such as "The couple danced (the tango) every Friday night last summer."
Both groups' reading times for critical segments were longer when the verb's transitivity bias did not match the sentence structure, particularly in intransitive sentences.
The results were generally consistent with the Lexical Bias Hypothesis, and demonstrated that lexical biases affect on-line processing of syntactically simple sentences in people with aphasia and controls.
BACKGROUND: Production of passive sentences is often impaired in agrammatic aphasia and has been attributed both to an underlying structural impairment (e.g., Schwartz, Saffran, Fink, Myers, & Martin, 1994) and to a morphological deficit (e.g., Caplan & Hanna, 1998; Faroqi-Shah & Thompson, 2003). However, the nature of the deficit in passive sentence production is not clear due to methodological issues present in previous studies. AIMS: This study examined active and passive sentence production in nine agrammatic aphasic speakers under conditions of structural priming using eyetracking to test whether structural impairments occur independently of morphological impairments and whether the underlying nature of error types is reflected in on-line measures, i.e., eye movements and speech onset latencies. METHODS #ENTITYSTARTX00026; PROCEDURES: Nine participants viewed and listened to a prime sentence in either active or passive voice, and then repeated it aloud. Next, a target picture appeared on the computer monitor and participants were instructed to describe it using the primed sentence structure. OUTCOMES #ENTITYSTARTX00026; RESULTS: Participants made substantial errors in sentence structure, i.e., passives with role reversals (RRs) and actives-for-passives, but few errors in passive morphology. Longer gaze durations to the first-produced noun for passives with RRs as compared to correct passives were found before and during speech. For actives-for-passives, however, this pattern was found during speech, but not before speech. CONCLUSIONS: The deficit in passive sentence production does not solely arise from a morphological deficit, rather it stems, at least in part, from a structural level impairment. The underlying nature of passives with RRs is qualitatively different from that of actives-for-passives, which cannot be clearly differentiated with off-line testing methodology.
BACKGROUND: Formal linguistic properties of sentences-both lexical, i.e., argument structure, and syntactic, i.e., movement-as well as what is known about normal and disordered sentence processing and production, were considered in the development of Treatment of Underlying Forms (TUF), a linguistic approach to treatment of sentence deficits in patients with agrammatic aphasia. TUF is focused on complex, non-canonical sentence structures and operates on the premise that training underlying, abstract, properties of language will allow for effective generalisation to untrained structures that share similar linguistic properties, particularly those of lesser complexity. AIMS: In this paper we summarise a series of studies focused on examining the effects of TUF. METHODS #ENTITYSTARTX00026;PROCEDURES: In each study, sentences selected for treatment and for generalisation analysis were controlled for their lexical and syntactic properties, with some structures related and others unrelated along theoretical lines. We use single-subject experimental designs-i.e., multiple baseline designs across participants and behaviours-to chart improvement in comprehension and production of both trained and untrained structures. One structure was trained at a time, while untrained sentences were tested for generalisation. Participants included individuals with mild to moderately severe agrammatic, Broca's aphasia with characteristic deficits patterns. OUTCOMES #ENTITYSTARTX00026; RESULTS: Results of this work have shown that treatment improves the sentence types entered into treatment, that generalisation occurs to sentences which are linguistically related to those trained, and that treatment results in changes in spontaneous discourse in most patients. Further, we have found that generalisation is enhanced when the direction of treatment is from more to less complex structures, a finding that led to the Complexity Account of Treatment Efficacy (CATE, Thompson, Shapiro, Kiran, & Sobecks, 2003). Finally, results of recent work showing that treatment appears to affect processing of trained sentences in real time and that treatment gains can be mapped onto the brain using functional magnetic resonance imaging (fMRI) are discussed. CONCLUSIONS: These findings indicate that TUF is effective for treating sentence comprehension and production in patients who present with language deficit patterns like those seen in our patients. Patients receiving this treatment show strong generalisation effects to untrained language material. Given the current healthcare climate, which limits the amount of treatment that aphasic patients receive following stroke, it is important that clinicians deliver treatment that results in optimal generalisation in the least amount of time possible.
BACKGROUND: Some individuals with agrammatic aphasia have difficulty producing verbs when naming and generating sentences (Miceli, Silveri, Villa, & Caramazza, 1984; Saffran, Schwartz, & Marin, 1980; Zingeser & Berndt, 1990). And when verbs are produced there is an over-reliance on verbs requiring simple argument structure arrangements (Thompson, Lange, Schneider, & Shapiro, 1997; Thompson, Shapiro, Schneider, & Tait, 1994). Verbs, as argument-taking elements, show especially complex semantic and argument structure properties. This study investigated the role these properties have on verb production in individuals with agrammatic aphasia. AIM: This treatment study examined the extent to which semantic class and argument structure properties of verbs influenced the ability of seven individuals with agrammatic Broca's aphasia to retrieve verbs and then use them in correct sentence production. Verbs from two semantic classes and two argument structure categories were trained using either a semantic or an argument structure verb retrieval treatment. Specifically, acquisition and generalisation to trained and untrained verbs within and across semantic and argument structure categories was examined. In addition, the influence of verb production on each participant's sentence production was also examined. METHODS #ENTITYSTARTX00026; PROCEDURES: Utilising a single-subject crossover design in combination with a multiple baseline design across subjects and behaviours, seven individuals with agrammatic aphasia were trained to retrieve verbs with specific argument structures from two semantic classes under two treatment conditions-semantic verb retrieval treatment and verb argument structure retrieval treatment. Treatment was provided on two-place and three-place motion or change of state verbs, counterbalanced across subjects and behaviours. A total of 102 verbs, depicted in black and white drawings, were utilised in the study, divided equally into motion and change of state verbs (semantic classes) and one-place, two-place, and three-place verbs (argument structure arrangements). Verbs were controlled for syllable length, picturability, phonological complexity, and frequency. These same stimulus items were used to elicit the sentence production probe. OUTCOMES #ENTITYSTARTX00026; RESULTS: Both treatments revealed significant effects in facilitating acquisition of verb retrieval in all participants. Minimal within and across verb category generalisation occurred. However, it was found that as retrieval of verbs improved, grammatical sentence production improved. This occurred without direct treatment on sentence production. CONCLUSIONS: The results of this study lend support for treatment focused on verb production with individuals with agrammatic aphasia and support the use of linguistic-based treatment strategies.
BACKGROUND: Production of grammatical morphology is typically impaired in agrammatic aphasic individuals, as is their capacity to produce the syntactic structure responsible for licensing that morphology. Whether these two impairments are causally related has been an issue of long-standing debate. If morphological deficits are a side-effect of underlying syntactic ones, as has been claimed (Friedmann & Grodzinsky, 1997; Izvorski & Ullman, 1999), therapy which improves the syntactic deficit should remediate the morphological deficit as well. This paper reports a case study of one individual with such co-occurring impairments and describes their recovery in response to linguistically-motivated treatment targeting his syntactic deficits. METHODS #ENTITYSTARTX00026; PROCEDURES: MD is a 56 year-old male diagnosed with non-fluent Broca's aphasia subsequent to a left-hemisphere CVA, with limited capacity to produce syntactically complex utterances and grammatical morphology. He was enrolled in therapy using Treatment of Underlying Forms (TUF; Thompson & Shapiro, 2005), targeting production of sentences involving Wh-movement (object relative clauses). MD participated in twice-weekly treatment sessions for approximately two months, with daily probes assessing his production of treated and untreated sentence types. In addition, probes assessing his grammatical morphology and sentence production were administered pre- and post-treatment. OUTCOMES #ENTITYSTARTX00026; RESULTS: Pre-treatment scores in tests of grammatical morphology and sentence production indicated deficits in both domains. During treatment, MD successfully acquired production of a variety of sentence with Wh-movement, though this did not generalize to sentences involving a grammatically distinct movement operation (NP-movement). Post-treatment scores also indicated a lack of improvement in production of grammatical morphology. CONCLUSIONS: The dissociation between MD's morphological and syntactic recovery indicates that the recovery of syntactic and morphological processes in aphasia may occur independently. This result is thus surprising under approaches in which morphological and syntactic impairments are strongly and causally related in aphasia, such as the Tree-Pruning Hypothesis (Friedmann, 2001; Friedmann & Grodzinsky, 1997). Further, these results reinforce the conclusion that aphasia treatment can lead to generalization, but only to linguistic material which is in a subset relation to trained structures (Thompson, Shapiro, Kiran & Sobecks, 2003).
BACKGROUND: Theories of comprehension deficits in Broca's aphasia have largely been based on the pattern of deficit found with movement constructions. However, some studies have found comprehension deficits with binding constructions, which do not involve movement. AIMS: This study investigates online processing and offline comprehension of binding constructions, such as reflexive (e.g., himself) and pronoun (e.g., him) constructions in unimpaired and aphasic individuals in an attempt to evaluate theories of agrammatic comprehension. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants were eight individuals with agrammatic Broca's aphasia and eight age-matched unimpaired individuals. We used eyetracking to examine online processing of binding constructions while participants listened to stories. Offline comprehension was also tested. OUTCOMES #ENTITYSTARTX00026; RESULTS: The eye movement data showed that individuals with Broca's aphasia were able to automatically process the correct antecedent of reflexives and pronouns. In addition, their syntactic processing of binding was not delayed compared to normal controls. Nevertheless, offline comprehension of both pronouns and reflexives was significantly impaired compared to the control participants. This comprehension failure was reflected in the aphasic participants' eye movements at sentence end, where fixations to the competitor increased. CONCLUSIONS: These data suggest that comprehension difficulties with binding constructions seen in agrammatic aphasic patients are not due to a deficit in automatic syntactic processing or delayed processing. Rather, they point to a possible deficit in lexical integration.
BACKGROUND: Speakers with agrammatic aphasia have greater difficulty producing unaccusative (float) compared to unergative (bark) verbs (Kegl, 1995; Lee & Thompson, 2004; Thompson, 2003), putatively because the former involve movement of the theme to the subject position from the post-verbal position, and are therefore more complex than the latter (Burzio, 1986; Perlmutter, 1978). However, it is unclear if and how sentence production processes are affected by the linguistic distinction between these two types of verbs in normal and impaired speakers. AIMS: This study examined real-time production of sentences with unergative (the black dog is barking) vs unaccusative (the black tube is floating) verbs in healthy young speakers and individuals with agrammatic aphasia, using eyetracking. METHODS #ENTITYSTARTX00026; PROCEDURES: Participants' eye movements and speech were recorded while they produced a sentence using computer displayed written stimuli (e.g., black, dog, is barking). OUTCOMES #ENTITYSTARTX00026; RESULTS: Both groups of speakers produced numerically fewer unaccusative sentences than unergative sentences. However, the eye movement data revealed significant differences in fixations between the adjective (black) vs the noun (tube) when producing unaccusatives, but not when producing unergatives for both groups. Interestingly, whereas healthy speakers showed this difference during speech, speakers with agrammatism showed this difference prior to speech onset. CONCLUSIONS: These findings suggest that the human sentence production system differentially processes unaccusatives vs unergatives. This distinction is preserved in individuals with agrammatism; however, the time course of sentence planning appears to differ from healthy speakers (Lee & Thompson, 2010).
BACKGROUND: Individuals with agrammatism show selective deficits in functional categories. The Tree Pruning Hypothesis (TPH; Friedmann & Grodzinsky, 1997) suggests that this results from inability to project certain nodes in the syntactic tree. On this account, higher nodes in the tree are more vulnerable than lower ones. Other theories, however, suggest that functional category impairments can be explained in the context of a morphological deficit (e.g., Arabatzi & Edwards, 2002; Penke, 2003; Thompson, Fix, Gitelman, 2002). AIMS: This study examined production of complementizers, tense, and agreement morphology in four English-speaking agrammatic participants to test the hierarchical nature of functional category deficits. The consistency of verb inflection errors was also tested under conditions examining a minimal set versus a full array of English inflected forms. MATERIALS #ENTITYSTARTX00026; PROCEDURES: In experiment 1, participants were asked to produce sentences by using a complementizer (i.e. whether, that, and if), a tense (-ed) or agreement marker (-s), in structured sentence elicitation tasks. In experiment 2, the participants' production of both finite and nonfinite verb inflection forms was examined. OUTCOME #ENTITYSTARTX00026; RESULTS: All participants produced complex sentences successfully using a complementizer, indicating intact projection to the Complementizer Phrase (CP). As for tense and agreement (structures within the Inflection Phrase (IP)), the agrammatic speakers were impaired in both categories and they showed higher scores in nonfinite vs. finite verb conditions. Further, their errors were dominated by substitutions, rather than omissions, with various non-target morphemes. CONCLUSIONS: Our agrammatic participants' deficits are morphological, rather than syntactic. The participants were able to project to the upper most structure, CP. They showed the ability to project verb inflection and to implement inflectional rules in their grammar. However, instantiation of grammatical markers sometimes failed to operate, resulting in incorrect inflectional forms. These findings suggest that within the domain of functional categories, IP- and CP-level deficits may result from disruption of differing underlying mechanisms and, therefore, they may require separate treatment strategies.
BACKGROUND: Classical aphasiology, based on the study of stroke sequelae, fuses speech fluency and grammatical ability. Nonfluent (Broca's) aphasia often is accompanied by agrammatism; whereas in the fluent aphasias grammatical deficits are not typical. The assumption that a similar relationship exists in primary progressive aphasia (PPA) has led to the dichotomization of this syndrome into fluent and nonfluent subtypes. AIMS: This study compared elements of fluency and grammatical production in the narrative speech of individuals with PPA to determine if they can be dissociated from one another. METHOD: Speech samples from 37 individuals with PPA, clinically assigned to agrammatic (N=11), logopenic (N=20) and semantic (N=6) subtypes, and 13 cognitively healthy control participants telling the "Cinderella Story" were analyzed for fluency (i.e., words per minute (WPM) and mean length of utterance in words (MLU-W)) and grammaticality (i.e., the proportion of grammatically correct sentences, open-to-closed-class word ratio, noun-to-verb ratio, and correct production of verb inflection, noun morphology, and verb argument structure.) Between group differences were analyzed for each variable. Correlational analyses examined the relation between WPM and each grammatical variable, and an off-line measure of sentence production. OUTCOMES AND RESULTS: Agrammatic and logopenic groups both had lower scores on the fluency measures and produced significantly fewer grammatical sentences than did semantic and control groups. However, only the agrammatic group evinced significantly impaired production of verb inflection and verb argument structure. In addition, some semantic participants showed abnormal open-to-closed and noun-to-verb ratios in narrative speech. When the sample was divided on the basis of fluency, all the agrammatic participants fell in the nonfluent category. The logopenic participants varied in fluency but those with low fluency showed variable performance on measures of grammaticality. Correlational analyses and scatter plots comparing fluency and each grammatical variable revealed dissociations within PPA participants, with some nonfluent participants showing normal grammatical skill. CONCLUSIONS: Grammatical production is a complex construct comprised of correct usage of several language components, each of which can be selectively affected by disease. This study demonstrates that individuals with PPA show dissociations between fluency and grammatical production in narrative speech. Grammatical ability, and its relationship to fluency, varies from individual to individual, and from one variant of PPA to another, and can even be found in individuals with semantic PPA in whom a fluent aphasia is usually thought to accompany preserved ability to produce grammatical utterances.
BACKGROUND: Phonologic text alexia (PhTA) is a reading disorder in which reading of pseudowords is impaired, but reading of real words is impaired only when reading text. Oral reading accuracy remains well preserved when words are presented individually, but when presented in text the part-of-speech effect that is often seen in phonologic alexia (PhA) emerges. AIMS: To determine whether repetition priming could strengthen and/or maintain the activation of words during text reading. METHODS #ENTITYSTARTX00026; PROCEDURES: We trained NYR, a patient with PhTA, to use a strategy, Sentence Building, designed to improve accuracy of reading words in text. The strategy required NYR to first read the initial word, and then build up the sentence by adding on sequential words, in a step-wise manner, utilizing the benefits of repetition priming to enhance accuracy. OUTCOMES #ENTITYSTARTX00026; RESULTS: When using the strategy, NYR displayed improved accuracy not only for sentences she practiced using the strategy, but unpracticed sentences as well. Additionally, NYR performed better on a test of comprehension when using the strategy, as compared to without the strategy. CONCLUSIONS: In light of research linking repetition priming to increased neural processing efficiency, our results suggest that use of this compensatory strategy improves reading accuracy and comprehension by temporarily boosting phonologic activation levels.
BACKGROUND: Drawing heavily on results from studies with divided visual field (dvf) presentation, current models of hemispheric differences in word semantic processing converge on a proposal (henceforth, "the standard model") that is increasingly being applied in studies of individuals with brain damage. According to this model, left hemisphere processes focus word meanings to their core, whereas right hemisphere processes keep wider representations active. AIMS: This paper has three aims: (a) to raise concerns about methodological aspects of the dvf studies that are usually cited in support for the standard model, specifically assumptions about interpretation of lateral dvf prime presentation and priming measures; (b) to highlight areas of further research and theoretical clarification, with reference to studies with central presentation and general models of word-meaning processing; and (c) to discuss the implications of these concerns for deriving a model of hemispheric differences in word-meaning processing, using evidence from paired word priming studies as an example. MAIN CONTRIBUTION: The paper discusses problematic assumptions about paired word priming studies of hemispheric contributions to word semantic processing and proposes further research to clarify these assumptions. Furthermore, it introduces an alternative interpretation of the available data, which provides a more parsimonious account of hemispheric engagement in the paired word semantic priming task. CONCLUSIONS: Current evidence about hemispheric differences in word-meaning processing is far from conclusive. It is important to consider alternative interpretations of the available evidence when applying models based on this evidence to the study of language disorders. The alternative account proposed in this paper suggests that LH processing, rather than generally reducing activated word meanings to their core, is important for maintaining meanings that are unambiguous and consistent.
BACKGROUND: Verbal play, the creative and playful use of language to make puns, rhyme words, and tease, is a pervasive and enjoyable component of social communication and serves important interpersonal functions. The current study examines the use of verbal play in the communicative interactions of individuals with Alzheimer's disease as part of a broader program of research on language-and-memory-in-use. AIMS: To document the frequency of verbal play in the communicative interactions of individuals with very mild Alzheimer's disease (AD) and their familiar communication partners. To characterize the interactional forms, resources, and functions of playful episodes. METHODS: Using quantitative group comparisons and detailed discourse analysis, we analyzed verbal play in the interactional discourse of five participants with very mild AD and five healthy (demographically matched) comparison participants. Each participant interacted with a familiar partner while completing a collaborative referencing task, and with a researcher between task trials. RESULTS: A total of 1,098 verbal play episodes were coded. Despite being in the early stages of AD, all the AD participants used verbal play. There were no significant group differences in the frequency of verbal play episodes or in the interactional forms, resources, or functions of those playful episodes between AD and healthy comparison pair sessions. CONCLUSIONS: The successful use of verbal play in the interactions of individuals with very mild AD and their partners highlights an area of preserved social communication. These findings represent an important step, both clinically and for research, in documenting the rich ways that individuals with early stage AD orchestrate interactionally meaningful communication with their partners through the use of interactional discourse resources like verbal play. This work also offers a promising clinical tool for tracking and targeting verbal play across disease progression.
BACKGROUND: Research has shown that individuals with probable Alzheimer's disease (PrAD) show impaired semantic knowledge of nouns. More specifically, while they demonstrate preserved superordinate category information, information regarding specific semantic attributes associated with subordinates appears to be disrupted. Results of some recent studies suggest that PrAD participants may also be impaired in processing semantic information associated with verbs. AIMS: Provided that a parallel exists between PrAD participants' noun and verb impairment, it is plausible that the semantic deficits observed in the breakdown of their noun lexicon may also exist in their knowledge of verb-related information. This experiment examined PrAD participants' knowledge of the semantic restrictions associated with the complements of verbs. METHODS #ENTITYSTARTX00026; PROCEDURES: Fourteen PrAD participants were asked to judge the semantic plausibility of 44 auditorily presented sentences. To examine their knowledge of the selection restriction of verbs, each verb was paired with two plausible complements that fully met the restriction, an implausible complement that violated the specific attributes required but belonged to the correct semantic category, and an implausible complement that violated the semantic category requirement. OUTCOMES #ENTITYSTARTX00026; RESULTS: Results showed that PrAD participants' errors were primarily on anomalous sentences that contained implausible complements that belonged to the correct semantic category. CONCLUSIONS: This finding confirms our hypothesis and suggests that a parallel pattern exists in PrAD participants' breakdown in noun and verb knowledge.
Studies of productive language in Alzheimer's disease (AD) have focused on formal testing of syntax and semantics but have directed less attention to naturalistic discourse and formulaic language. Clinical observations suggest that individuals with AD retain the ability to produce formulaic language long after other cognitive abilities have deteriorated.
This study quantifies production of formulaic expressions in the spontaneous speech of individuals with AD. Persons with early- and late-onset forms of the disease were compared.
Conversational language samples of individuals with early- (n = 5) and late-onset (n = 6) AD and healthy controls (n = 5) were analyzed to determine whether formulaic language, as measured by the number of words in formulaic expressions, differs between groups.
Results indicate that individuals with AD, regardless of age of onset, used significantly more formulaic expressions than healthy controls. The early- and late-onset AD groups did not differ on formulaic language measures.
These findings contribute to a dual process model of cerebral function, which proposes differing processing principles for formulaic and novel expressions. In this model, subcortical areas, which remain intact into late in the progression of Alzheimer's disease, play an important role in the production of formulaic language. Applications to clinical practice include identifying preserved formulaic language and providing informed counseling to patient and family.
The Lexical Bias Hypothesis (Gahl, 2002) claims that people with aphasia have difficulty understanding sentences when the verb's argument structure bias conflicts with the sentence structure. This hypothesis can account for comprehension deficits that affect simple sentences, but the role of verb bias has not been clearly demonstrated in temporarily ambiguous sentences.
This study examined how verb bias affects comprehension of temporarily ambiguous and unambiguous sentences using self-paced reading.
People with aphasia and controls read sentences that contained sentential complements (e.g., The talented photographer accepted (that) the fire could not have been prevented.). The main verb was biased to take a direct object (e.g., accepted) or a sentential complement (e.g., admitted). In addition, the sentential complement was either introduced by the complementizer that (i.e., unambiguous) or unmarked (i.e., ambiguous).
The people with aphasia's reading times were affected more by verb bias than by the presence of the complementizer, whereas the control group's reading times were more affected by the presence or absence of the complementizer.
The results were generally consistent with the Lexical Bias Hypothesis, and showed that a mismatch between verb bias and sentence structure affected processing of unambiguous and temporarily ambiguous sentences in people with aphasia.
Background: We have worked to develop rich communicative environments as a way to study the real-world demands that communication places on language-and-memory-in-use by focusing on the impact of declarative memory impairments on social interaction. Here, we analyse procedural discoursethe practice of telling another person how to do something (e.g., giving directions). Aims: To facilitate comparison to previous research on procedural discourse, this study includes an analysis of the procedural steps produced by target participants. This study also offers a novel approach by focusing on the collaborative and interactional nature of how procedural discourse is produced to meet the demands of real-world communication. Methods & Procedures: Procedural discourse samples were obtained on nine individuals with hippocampal amnesia and nine comparison participants each interacting with a clinician. Using traditional procedural and linguistic-based measures and interactional discourse measures, we analysed target participants' individual contribution to procedural descriptions and contributions of both the clinician and participant across the samples. Outcomes & Results: No significant group differences were observed for procedural and linguistic-based measures. Rather, participants with amnesia were more reliably distinguished on interactional discourse measures (e.g., lack of engagement and support for clinician, less detail and personalisation of procedural steps, difficulty in shifting social stance). Conclusions: These findings accord with our previous research suggesting that hippocampal amnesia disrupts the flexible deployment of declarative knowledge and the ability to shift social stances/perspectives to meet the demands of social interaction. These findings contribute to the evolving portrait of language-and-memory-in-use and further support the value of examining interactional aspects of communication in the empirical study of brain-behaviour relationships.
BACKGROUND: Definite references signal a speaker's belief that a listener can uniquely identify the referent (e.g., the dog, as the only dog among a group of animals). Clark's (1992) collaborative referencing model provides a way to examine the speaker's display of confidence that his/her reference will be understood by the listener without further clarification. We previously found that amnesia participants, as directors in a barrier task with a familiar partner, used referencing forms that displayed less confidence than forms used by comparison participants. If this is an interactional consequence of managing the memory impairment (as opposed to a language deficit), we should also expect a decrease in definite referencing by their partners. AIMS: To examine the use of definite references by healthy non-brain-damaged participants when speaking to their memory-impaired partner during repeated trials of a barrier task. METHODS #ENTITYSTARTX00026; PROCEDURES: We replicated our previous work with 11 of the same participant pairs-6 individuals with hippocampal amnesia and 5 comparison participants-each of whom was paired with a familiar partner of their choosing. Focusing on the productions of the partners (i.e., partners became directors) we (1) coded referential expressions as definite or indefinite; (2) tracked changes in the use of indefinite and definite references across trials; and (3) compared data to previous analyses (when amnesia participants were directors). OUTCOMES #ENTITYSTARTX00026; RESULTS: The productions of comparison pairs were overwhelming definite (95%, 1359). In sharp contrast, partners of the amnesia participants used a definite initiating reference less than half the time (48%, 825), when speaking to their memory-impaired partner and used definite references that signalled a lack of confidence more often and across more trials. CONCLUSIONS: These findings support the assumption that disruptions in language-and-memory-in-use are not limited to the productions of the individuals with amnesia, but rather extend to the discourse of their communication partners. Observing disruptions in the use of definite references of individuals with intact language and declarative memory, when communicating with their partner with amnesia, points to the complex interaction of memory and language. Even when attention is paid to grammatical forms, the decisions are never linguistic alone.
BACKGROUND: While the neural substrates and cognitive components of creativity have received considerable attention in cognitive neuroscience, the creative use of language in social interaction has been less well studied. As part of a broader program of research on language-and-memory-in-use in individuals with hippocampal amnesia, we analyzed verbal play, a creative use of language that is pervasive in everyday communicative interaction. AIMS: To identify instances of creative uses of language in the protocols of social and collaborative interactions, to characterize the qualitative nature, and to determine the frequency of these interactions initiated by participants with hippocampal amnesia vs. comparison participants in order to ascertain whether amnesia impairs this aspect of social communication. METHODS AND PROCEDURES: This study uses quantitative group comparisons and detailed discourse analysis to analyze verbal play in the interactional discourse sessions of 4 participants with hippocampal amnesia and 4 healthy (demographically matched) comparison participants, each interacting with a familiar partner while completing a collaborative referencing task and with a researcher between task trials. RESULTS: All participants used verbal play. However, significantly fewer episodes were initiated in sessions with amnesia participants (312) and by participants with amnesia themselves (187) than in sessions with comparison participants (572) and by comparison participants (395). No significant group differences were observed for interactional forms, resources, or functions. Qualitative differences were also observed in amnesia sessions (e.g., more rotely produced episodes, lack of thematically linked episodes). CONCLUSIONS: These findings suggest that hippocampal amnesia disrupts the creative use of language in social interaction and accord with our previous work pointing to impairments in language-and-memory-in-use more broadly. These findings highlight the interdependence of language and memory especially in the interactional aspects of communication.
Background: Discourse cohesion and coherence gives our communication continuity. Deficits in cohesion and coherence have been reported in patients with cognitive-communication disorders (e.g., TBI, dementia). However, the diffuse nature of pathology and widespread cognitive deficits of these disorders have made identification of specific neural substrates and cognitive systems critical for cohesion and coherence challenging.
Aims: Taking advantage of a rare patient group with selective and severe declarative memory impairments, the current study attempts to isolate the contribution of declarative memory to the successful use of cohesion and coherence in discourse.
Methods & Procedures: Cohesion and coherence were examined in the discourse of six participants with hippocampal amnesia and six demographically matched comparison participants. Specifically, this study (1) documents the frequency, type, and completeness of cohesive ties; (2) evaluates discourse for local and global coherence; and (3) compares use of cohesive ties and coherence ratings in amnesia and healthy participants.
Outcomes & Results: Overall, amnesia participants produced fewer cohesive ties per T-unit, the adequacy of their ties were more often judged to be incomplete, and the ratings of their local coherence were consistently lower than comparison participants.
Conclusions: These findings suggest that declarative memory may contribute to the discursive use of cohesion and coherence. Broader notions of cohesion, or interactional cohesion, i.e., cohesion across speakers (two or more people), time (days, weeks), and communicative resources (gesture), warrant further study as the experimental tasks used in the literature, and here, may actually underestimate or overestimate the extent of impairment.
BACKGROUND: There is still a dearth of information about grammatical aspects of language production in aphasia. AIMS: Making novel use of methods of elicited production aimed at testing the limits of competence, we studied three cases of chronic aphasia, stemming from major stroke. We asked: (1) Whether the elicited production method reveals sparing of language abilities not readily evidenced in spontaneous utterances or on conventional aphasia tests. (2) Which language production abilities survive damage to both Broca's region and Wernicke's region? MATERIALS & PROCEDURES: Targeted words, morphological and syntactic structures were elicited by sentence completion with supporting linguistic and visual context. Targets were never modelled during the procedure. For verbs, visual and auditory contexts emphasise completed actions, targeting past tense forms. Lesion description was based on structural MRI scans. OUTCOMES & RESULTS: The three participants showed partially spared ability to produce nouns, adjectives, and verb stems in context. The elicitation method proved more productive in some cases than picture prompts or sentence prompts. Past tense inflections were usually omitted. Hence stems and inflections were dissociable. Two participants showed partial success with the passive, and no participant produced a full relative clause, including the relative pronoun, but two produced reduced forms of subject relatives. Partial sparing of production capability in these cases points to the likely importance of portions of the left hemisphere remote from Broca and Wernicke regions. CONCLUSIONS: This application of elicited production methodology demonstrates possibilities of lexical, morphological, and syntactic production not evident in spontaneous utterances or by conventional aphasia tests. Some lexical and grammatical capabilities survived massive damage to both anterior and posterior portions of the left hemisphere.
BACKGROUND: Spaced Retrieval (SR) is a treatment approach developed to facilitate recall of information by individuals with dementia. Essentially an errorless learning procedure that can be used to facilitate recall of a variety of information, SR gradually increases the interval between correct recall of target items. AIMS: Given the success of using SR in dementia, the purpose of this study was to explore its usefulness in improving naming by individuals with aphasia. The rate of acquisition and retention of items was compared between SR and a more traditional treatment technique-cueing hierarchy (CH). Also, each oral naming treatment was run concurrently with a single word writing treatment. METHODS #ENTITYSTARTX00026; PROCEDURES: Three participants who had moderate or severe naming impairments and agraphia were studied. Single-subject design was applied across oral and written naming and treated and untreated items. OUTCOMES #ENTITYSTARTX00026; RESULTS: The results indicate that for these participants, SR resulted in improved naming of specific items. The data further suggest that SR compared favourably to CH with regard to both acquisition and retention of items. The participants also benefited nicely from the writing treatment. CONCLUSIONS: These findings suggest SR may be an alternative for managing naming impairment resulting from aphasia. Furthermore, the study supports providing treatments aimed at two different modalities concurrently.
Differences in processing nouns and verbs have been investigated intensely in psycholinguistics and neuropsychology in past decades. However, the majority of studies examining retrieval of these word classes have involved tasks of single word stimuli or responses. While the results have provided rich information for addressing issues about grammatical class distinctions, it is unclear whether they have adequate ecological validity for understanding lexical retrieval in connected speech which characterizes daily verbal communication. Previous investigations comparing retrieval of nouns and verbs in single word production and connected speech have reported either discrepant performance between the two contexts with presence of word class dissociation in picture naming but absence in connected speech, or null effects of word class. In addition, word finding difficulties have been found to be less severe in connected speech than picture naming. However, these studies have failed to match target stimuli of the two word classes and between tasks on psycholinguistic variables known to affect performance in response latency and/or accuracy.
The present study compared lexical retrieval of nouns and verbs in picture naming and connected speech from picture description, procedural description, and story-telling among 19 Chinese speakers with anomic aphasia and their age, gender, and education matched healthy controls, to understand the influence of grammatical class on word production across speech contexts when target items were balanced for confounding variables between word classes and tasks.
Methods & procedures:
Elicitation of responses followed the protocol of the AphasiaBank consortium (http://talkbank.org/AphasiaBank/). Target words for confrontation naming were based on well-established naming tests, while those for narrative were drawn from a large database of normal speakers. Selected nouns and verbs in the two contexts were matched for age-of-acquisition (AoA) and familiarity. Influence of imageability was removed through statistical control.
Outcomes & results:
When AoA and familiarity were balanced, nouns were retrieved better than verbs, and performance was higher in picture naming than connected speech. When imageability was further controlled for, only the effect of task remained significant.
The absence of word class effects when confounding variables are controlled for is similar to many previous reports; however, the pattern of better word retrieval in naming is rare but compatible with the account that processing demands are higher in narrative than naming. The overall findings have strongly suggested the importance of including connected speech tasks in any language assessment and evaluation of language rehabilitation of individuals with aphasia.
There are several methods of delivering cortical brain stimulation to modulate cortical excitability and interest in their application as an adjuvant strategy in aphasia rehabilitation after stroke is growing. Epidural cortical stimulation, although more invasive than other methods, permits high frequency stimulation of high spatial specificity to targeted neuronal populations.
First, we review evidence supporting the use of epidural cortical stimulation for upper limb recovery after focal cortical injury in both animal models and human stroke survivors. These data provide the empirical and theoretical platform underlying the use of epidural cortical stimulation in aphasia. Second, we summarize evidence for the application of epidural cortical stimulation in aphasia. We describe the procedures and primary outcomes of a safety and feasibility study (Cherney, Erickson & Small, 2010), and provide previously unpublished data regarding secondary behavioral outcomes from that study.
In a controlled study comparing epidural cortical stimulation plus language treatment (CS/LT) to language treatment alone (LT), eight stroke survivors with nonfluent aphasia received intensive language therapy for 6 weeks. Four of these participants also underwent surgical implantation of an epidural stimulation device which was activated only during therapy sessions. Behavioral data were collected before treatment, immediately after treatment, and at 6 and 12 weeks following the end of treatment. The effect size for the primary outcome measure, the Western Aphasia Battery Aphasia Quotient, was benchmarked as moderate from baseline to immediately post-treatment, and large from baseline to the 12-week follow-up. Similarly, effect sizes obtained at the 12-week follow-up for the Boston Naming Test, the Communicative Effectiveness Index, and for correct information units on a picture description task were greater than those obtained immediately post treatment. When effect sizes were compared for individual subject pairs on discourse measures of content and rate, effects were typically larger for the investigational subjects receiving CS/LT than for the control subjects receiving LT alone. These analyses support previous findings regarding therapeutic efficacy of CS/LT compared to LT i.e. epidural stimulation of ipsilesional premotor cortex may augment behavioral speech-language therapy, with the largest effects after completion of therapy.
Continued investigation of epidural cortical stimulation in combination with language training in post-stroke aphasia should proceed cautiously. Carefully planned studies that customize procedures to individual profiles are warranted. Information from research on non-invasive methods of CS/LT may also inform future studies of epidural cortical stimulation.
Background: Adults with aphasia often try mightily to produce specific words, but their word‐finding attempts are frequently unsuccessful. However, the word retrieval process may contain rich information that communicates a desired message regardless of word‐finding success. Aims: The original article reprinted here reports an investigation that assessed whether patient‐generated self cues inherent in the word retrieval process could be interpreted by listener/observers and improve on communicative effectiveness for adults with aphasia. The newly added commentary identifies and reports tentative conclusions from 18 investigations of self‐generated cues in aphasia since the 1982 paper. It further provides a rationale for increasing research on self‐generated cueing and notes a surprising lack of attention to the questions investigated in the original article. The original research is also connected with more recent qualitative investigations of interactional, as opposed to transactional, communicative exchange. Methods & Procedures: While performing single‐word production tasks, 10 adults with aphasia produced 107 utterances that contained spontaneous word retrieval behaviours. To determine the “communicative value” of these behaviours, herein designated self cues or self‐generated cues, the utterance‐final (potential target) word was edited out and the edited utterances were dubbed onto a videotape. Six naïve observers, three of whom received some context about the nature of word retrieval in aphasia and possible topics for the utterances, and three of whom got no information, predicted the target word of each utterance from the word‐finding behaviours alone. The communicative value of the self‐generated cues was determined for each individual with aphasia by summing percent correct word retrieval and percent correct observer prediction of target words, based on word retrieval behaviours. The newly added commentary describes some challenges of investigating a “communicative value” outcome, and indicates what would and would not change about the methods, if we did the study today. Outcomes & Results: The observer group that was given some context information appeared to be more successful at predicting target words than the group without any such information. Self‐generated cues enhanced communication for the majority of individuals with aphasia, with some cues (e.g., descriptions/gestures of action or function) appearing to carry more communicative value than others (e.g., semantic associates). The commentary again indicates how and why we would change this portion of the investigation if conducting the study at this time. Conclusions: The results are consistent with Holland's (19777.
Holland , A. 1977. “Some practical considerations in aphasia rehabilitation.”. In Rationale for Adult Aphasia Therapy, Edited by:
Sullivan , M and
Kommers , M. S . Nebraska: Univ. of Neb. Med. Center. View all references) premise that people with aphasia do well at communication, regardless of the words they produce. The finding that minimal context information may assist observers in understanding the communicative intent of people with aphasia has important implications for training family members to interpret self‐generated cues. The new commentary reinforces these conclusions, highlights potential differences between self cues that improve word‐finding success and those that enhance message transmission, and points to some additional research needs.
BACKGROUND: Recent research suggests that the complexity of treatment stimuli influences the effectiveness of treatment. However, no studies have examined the role of complexity on sound production treatment in adult individuals with sound production impairments. AIMS: This study examines effects of syllable complexity on treatment outcome in two patients with acquired sound production problems. Complexity is defined in terms of syllable structure: clusters are more complex than singletons. Using a single-subject multiple-baseline design, we address the question: Is treatment of complex syllables more effective than treatment of simple syllables? METHODS #ENTITYSTARTX00026; PROCEDURES: Two patients with aphasia and apraxia of speech were trained to produce complex or simple syllables (using modelling). Improvement was measured by percent correct on a word and nonword repetition test. OUTCOMES #ENTITYSTARTX00026; RESULTS: We found that both treatment on simple syllables and treatment on complex syllables led to improved production of simple syllables, while treatment of complex syllables also led to improvement on some complex syllables for one of the two patients. CONCLUSIONS: These results suggests that training complex items is more effective than training simple items, at least for some patients. Possible reasons for lack of stronger effects are discussed, as well as directions for future research.
Background: Loss of fluency is a significant source of functional impairment in many individuals with aphasia. Repetitive transcranial magnetic stimulation (rTMS) administered to the right inferior frontal gyrus (IFG) has been shown to facilitate naming in persons with chronic left hemisphere stroke and non-fluent aphasia. However, changes in fluency in aphasic participants receiving rTMS have not been adequately explored. Aims: To determine whether rTMS improves fluency in individuals with chronic nonfluent aphasia, and to identify aspects of fluency that are modulated in persons who respond to rTMS. Methods & Procedures: Ten individuals with left hemisphere MCA strokes and mild to moderate non-fluent aphasia participated in the study. Before treatment participants were asked to describe the Cookie Theft picture in three separate sessions. During treatment all participants received 1200 pulses of 1 Hz rTMS daily in 10 sessions over 2 weeks at a site that had previously been shown to improve naming. Participants repeated the Cookie Theft description 2 months after treatment. Five participants initially received sham stimulation instead of real TMS; 2 months after sham treatment these individuals received real rTMS. Performance both at baseline and after stimulation was coded using Quantitative Production Analysis (Saffran, Berndt, & Schwartz, 198931.
Saffran , E. M. ,
Berndt , R. S. and
Schwartz , M. F. 1989. The quantitative analysis of agrammatic production: Procedure and data. Brain & Language, 37: 440–479. [CrossRef], [PubMed], [Web of Science ®], [CSA]View all references) and Correct Information Unit (Nicholas & Brookshire, 199325.
Nicholas , L. E. and
Brookshire , R. H. 1993. A system for quantifying the informativeness and efficiency of the connected speech of adults with aphasia. Journal of Speech and Hearing Research, 36: 338–350. [CrossRef], [PubMed]View all references) analysis. Outcomes & Results: Across all participants (n = 10), real rTMS treatment resulted in a significant increase in multiple measures of discourse productivity compared to baseline performance. There was no significant increase in measures of sentence productivity or grammatical accuracy. There was no significant increase from baseline in the sham condition (n = 5) on any study measures. Conclusions: Stimulation of the right IFG in patients with chronic non-fluent aphasia facilitates discourse production. We posit that this effect may be attributable to improved lexical-semantic access.
BACKGROUND: Previous studies of the relationship between perfusion, diffusion, and stroke suggest that the extent of cerebral hypoperfusion may be a better indicator of neurological status than lesion size in the early phases of recovery. It is not clear how these factors are related to aphasia severity. AIMS: The purpose of this study was to investigate the relationship between cerebral perfusion, diffusion, and aphasia severity in stroke. METHODS #ENTITYSTARTX00026; PROCEDURE: Nine participants were examined within 24 hours of stroke onset and six were re-examined at 1 month post stroke. The examination included administration of an aphasia test, a face recognition task, and a neuroimaging session including T2-, perfusion-, and diffusion-weighted MRI. OUTCOMES #ENTITYSTARTX00026; RESULTS: Participants with a variety of aphasia types and severity were included in the study. Visual inspection suggested larger perfusion abnormality than the actual lesion in eight of nine subjects at day 1. The correlation between aphasia severity and hypoperfusion was significant at day 1 and at 1 month post stroke. However, this was not the case for the relationship between aphasia severity and lesion size where the correlation was not statistically significant at day 1 or at 1 month post stroke. CONCLUSIONS: These results suggest that cerebral hypoperfusion is a more accurate indicator of aphasia severity in early stroke than lesion volume.
BACKGROUND: Functional and structural neuroimaging techniques can increase our knowledge about the neural processes underlying recovery from post-stroke language impairments (aphasia). AIMS: In the present review we highlight recent developments in neuroimaging research of aphasia recovery. MAIN CONTRIBUTION: We review (a) cross-sectional findings in aphasia with regard to local brain functions and functional connectivity, (b) structural and functional imaging findings using longitudinal (intervention) paradigms, (c) new adjunct treatments that are guided by functional imaging techniques (e.g., electrical brain stimulation) and (d) studies related to the prognosis of language recovery and treatment responsiveness after stroke. CONCLUSIONS: More recent developments in data acquisition and analysis foster better understanding and more realistic modelling of the neural substrates of language recovery after stroke. Moreover, the combination of different neuroimaging protocols can provide converging evidence for neuroplastic brain remodelling during spontaneous and treatment-induced recovery. Researchers are also beginning to use sophisticated imaging analyses to improve accuracy of prognosis, which may eventually improve patient care by allowing for more efficient treatment planning. Brain stimulation techniques offer a new and exciting way to improve the recovery potential after stroke.
BACKGROUND: Individuals with non-fluent aphasia have difficulty producing syntactically laden words, such as function words, whereas individuals with fluent aphasia often have difficulty producing semantically specific words. It is hypothesised that such dissociations arise, at least in part, from a trade-off between syntactic and semantic sources of input to lexical retrieval. AIMS: The aims of this study were (a) to identify quantitative measures of the semantic content of narrative for people with aphasia that are reliable indicators of semantic competence, independent of overall aphasia severity; (b) to determine whether these measures distinguish between fluent and non-fluent aphasia; and (c) to assess whether individuals with fluent and non-fluent aphasia show a trade-off between measures of syntactic and semantic production. METHODS #ENTITYSTARTX00026; PROCEDURES: Connected speech samples were elicited from 16 participants with aphasia, 8 fluent and 8 non-fluent. The semantic sufficiency of the samples was analysed by measuring the proportion of correct information units (CIUs), the type-token ratios (TTRs) of content words, and the proportion of semantically specific ("heavy") to semantically general ("light") verbs produced. These measures were then correlated with syntactic measures from the QPA (Berndt, Wayland, Rochon, Saffran, & Schwartz, 2000) across and within participant groups. OUTCOMES #ENTITYSTARTX00026; RESULTS: CIUs were found to reflect primarily aphasia severity, and not to differentiate between fluent and non-fluent groups. TTRs were also strongly influenced by severity among fluent, but not non-fluent, participants. The ratio of heavy to light verbs reliably distinguished the groups, and showed different patterns of correlation with the syntactic measures. CONCLUSIONS: Results show some evidence for a trade-off between syntactic and semantic inputs to word retrieval, at least among non-fluent participants. The heavy-light verb ratio provides information about semantic specificity, beyond what is provided by the CIU or TTR measures.
Primary progressive aphasia (PPA) is a devastating neurodegenerative syndrome involving the gradual development of aphasia, slowly impairing the patient's ability to communicate. Pharmaceutical treatments do not currently exist and intervention often focuses on speech-language behavioral therapies, although further investigation is warranted to determine how best to harness functional benefits. Efforts to develop pharmaceutical and behavioral treatments have been hindered by a lack of standardized methods to monitor disease progression and treatment efficacy.
Here we describe our current approach to monitoring progression of PPA, including the development and applications of a novel clinical instrument for this purpose, the Progressive Aphasia Severity Scale (PASS). We also outline some of the issues related to initial evaluation and longitudinal monitoring of PPA.
Methods & procedures:
In our clinical and research practice we perform initial and follow-up assessments of PPA patients using a multi-faceted approach. In addition to standardized assessment measures, we use the PASS to rate presence and severity of symptoms across distinct domains of speech, language, and functional and pragmatic aspects of communication. Ratings are made using the clinician's best judgment, integrating information from patient test performance in the office as well as a companion's description of routine daily functioning.
Outcomes & results:
Monitoring symptom characteristics and severity with the PASS can assist in developing behavioral therapies, planning treatment goals, and counseling patients and families on clinical status and prognosis. The PASS also has potential to advance the implementation of PPA clinical trials.
PPA patients display heterogeneous language profiles that change over time given the progressive nature of the disease. The monitoring of symptom progression is therefore crucial to ensure that proposed treatments are appropriate at any given stage, including speech-language therapy and potentially pharmaceutical treatments once these become available. Because of the discrepancy that can exist between a patient's daily functioning and standardized test performance, we believe a comprehensive assessment and monitoring battery must include performance-based instruments, interviews with the patient and partner, questionnaires about functioning in daily life, and measures of clinician judgment. We hope that our clinician judgment-based rating scale described here will be a valuable addition to the PPA assessment and monitoring battery.
BACKGROUND: The study of communicative gestures is one of considerable interest for aphasia, in relation to theory, diagnosis, and treatment. Significant limitations currently permeate the general (psycho)linguistic literature on gesture production, and attention to these limitations is essential for both continued investigation and clinical application of gesture for people with aphasia. AIMS: The aims of this paper are to discuss issues imperative to advancing the gesture production literature and to provide specific suggestions for applying the material herein to studies in gesture production for people with aphasia. MAIN CONTRIBUTION: Two primary perspectives in the gesture production literature are distinct in their proposals about the function of gesture, and about where gesture arises in the communication stream. These two perspectives will be discussed, along with three elements considered to be prerequisites for advancing the research on gesture production. These include: operational definitions, coding systems, and the temporal synchrony characteristics of gesture. CONCLUSIONS: Addressing the specific elements discussed in this paper will provide essential information for both continued investigation and clinical application of gesture for people with aphasia.
Three variants of primary progressive aphasia (PPA), distinguished by language performance and supportive patterns of atrophy on imaging, have different clinical courses and the prognoses for specific functions. For example, semantic variant PPA alone is distinguished by impaired word comprehension. However, sometimes individuals with high education show normal performance on word comprehension tests early on, making classification difficult. Furthermore, as the condition progresses, individuals with other variants develop word comprehension deficits and other behavioral symptoms, making distinctions between variants less clear. Longitudinal brain imaging allows identification of specific areas of atrophy in individual patients, which identifies the location of disease in each patient.
We hypothesized that the areas of atrophy in individual PPA participants would be closely correlated with decline in word comprehension over time. We propose that areas where tissue volume is correlated with word comprehension are areas that: (1) are essential for word comprehension, (2) compensate for word comprehension in some individuals with semantic variant PPA early in the course; and (3) show atrophy in individuals with logopenic and nonfluent variant PPA only late in the course.
Methods and procedures:
Fifteen participants with PPA (5 logopenic variant PPA; 8 semantic variant PPA; 2 nonfluent/agrammatic variant PPA; mean age 67.8), underwent high resolution MRI and cognitive tests at least 9 months apart. The correlations between change in regional volumes and change in auditory word comprehension scores were investigated using Spearman test.
Outcomes & results:
While scores on auditory word comprehension at Time 1 were correlated with volume loss in right and left temporal pole and left inferior temporal cortex (areas of atrophy associated with semantic variant PPA), deterioration in auditory word comprehension from Time 1 to Time 2 was associated with individual atrophy in left middle temporal cortex, left angular gyrus, and right inferior and middle temporal cortex.
Progressive atrophy in focal areas surrounding left temporal pole and left inferior temporal cortex, and right homologous area is closely related to progressive decline in auditory word comprehension. These correlations likely reflect areas that help support auditory word comprehension, effectively compensating for subtle deficits in some individuals early in the course of semantic variant PPA, as well as areas that are critical for auditory word comprehension that eventually atrophy in individuals with other variants of PPA. Individual patterns of atrophy also help us understand and predict the clinical course of individuals, such as associated behavioral or motor deficits.
Among the obstacles to demonstrating efficacy of pharmacological intervention for aphasia is quantifying patients' responses to treatment in a statistically valid and reliable manner. In many of the review papers on this topic (e.g., Berthier et al., 2011; de Boissezon, Peran, de Boysson, & Démonet, 2007; Small & Llano, 2009), detailed discussions of various methodological problems are highlighted, with some suggestions on how these shortcomings should be addressed. Given this deep understanding of caveats associated with the experimental design of aphasia pharmacotherapy studies (e.g., Berthier et al., 2011), investigations continue to produce inconsistent results.
In this review paper we suggest that inclusion of theory-driven linguistic measures in aphasia pharmacotherapy studies would add an important step toward elucidating precise patterns of improvement in language performance resulting from pharmacotherapeutic intervention.
We provide a brief review of the clinical approaches currently used in pharmacotherapy studies of aphasia, which often lack psycholinguistic grounding. We then present ways in which psycholinguistic models can complement this approach, offering a rationale for task selection, and as a result, lead to a better understanding of treatment effects. We then follow with an example of how such an integrative approach can be implemented in studies targeting stress reduction in people with aphasia, via beta-blocking agents, as a means to augment language performance, using the psycholinguistic framework of "linguistic anxiety" outlined in Cahana-Amitay et al, 2011 as our guideline.
We conclude that the incorporation of psycholinguistic models into aphasia pharmacotherapy studies can increase the resolution with which we can identify functional changes.