Article

Eye Vergence Responses During an Attention Task in Adults With ADHD and Clinical Controls

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Abstract

Objective: ADHD patients show poor oculomotor control and recent studies show that attention-related eye vergence is weak in ADHD children. We aimed to assess vergence as a potential diagnostic biomarker for ADHD in adults. Method: We assessed the modulation in the angle of vergence while performing an attention task ( N = 144), comparing the results for adults previously diagnosed with ADHD ( N = 108) with age-matched clinical controls ( N = 36). Results: Significant differences in eye vergence response modulation between clinical controls and ADHD patients were documented. Diagnostic test accuracy was 79%. Conclusion: In combination with an attention task, eye vergence responses could be used as an objective marker to support the clinical diagnosis of adult ADHD.

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... These so-called 'cognitive vergence' responses are associated to orienting visual attention and correlate with the late components of visual Event Related Potentials (Sole Puig et al., 2016) that reflect cognitive processing. Cognitive vergence is present in cognitive healthy persons at early developmental stages Sup er, 2018, 2019) but is atypical in patients suffering attention problems, such as ADHD (Sole Puig et al., 2015, Varela Casal et al., 2019Jim enez et al., 2020) or dyslexia (Jim enez et al., 2021). ...
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Background Facial expression of emotion is fundamental to human social interactions. Attention to relevant cues in ADHD and ASD patients are believed to underlie difficulties in recognizing emotions. Cognitive vergence eye movements during gaze fixation have a role in attention. Here we evaluate a possible role of cognitive vergence in facial emotion recognition. Methods We recorded eye vergence from children with ADHD (n = 27), ASD (n = 18) or ADHD&ASD (n = 15) and from neurotypical (NT; n = 31) children during a facial emotion recognition task. Results Vergence responses to relevant stimuli were stronger than those to distractor stimuli. ADHD and ADHD&ASD children showed shorter gaze fixation duration and weaker cognitive vergence responses to the eye regions of the face stimuli compared to neurotypically developing children. In contrast, gaze behavior and vergence responses of ASD children resembled that of neurotypically developing children. Conclusion These results provide evidence for the idea that impaired recognition of facial expression of emotion is a problem of attending the relevant cues to adequately recognize facial expressions. As ASD patients resembled that of NT, cognitive vergence represents an etiological difference between ADHD and ASD.
... Moreover, the onset latency and the strength of vergence responses correlate with the onset latency and strength of late EEG responses that represent visual attention (Solé Puig et al., 2016). A possible role of vergence in attention is supported by evidence showing that vergence responses predict memory Esposito & Supèr, 2019) and perception (Solé Puig, Puigcerver, & et al., 2013;, and that people with attention difficulties show poor vergence responses when performing an attention task Varela et al., 2018;Jiménez, Avella-Garcia, & et al., 2020;Jiménez, Romeo, & et al., 2020). Vergence responses are independent of the occurrence of micro-saccades (Solé Puig, Puigcerver, & et al., 2013) but there exist an interaction with pupil response and accommodation. ...
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Figure-ground, that is the segmentation of visual information into objects and their surrounding backgrounds, provides structure for visual attention. Recent evidence shows a novel role of vergence eye movements in visual attention. In the present work, vergence responses during figure-ground segregation tasks are psychophysically investigated. We show that during a figure-ground detection task, subjects convergence their eyes. Vergence eye movements are larger in figure trials than in ground trials. In detected figures trials, vergence are stronger than in trials where the figure went unnoticed. Moreover in figure trials, vergence responses are stronger to low-contrast figures than to high-contrast figures. We argue that these discriminative vergence responses have a role in figure-ground.
... In addition, the scale's strength compared to other potential biomarkers of ADHD has not been established (e.g., EEG theta/beta ratio [EEG-TBR]; [65]), including those based on eye movement analysis. For example, analysis of eye vergence responses while adult participants performed an attentional task appeared to provide a somewhat stronger discriminative capacity than that found in the current study (sensitivity = 79% and specificity = 75%; [66]). This emphasizes the need for more research, both to validate the current findings and to compare the utility of eye movement measures, either alone or when combined with conventional CPT measures, to other biomarkers of ADHD. ...
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Atypical motor coordination and cognitive processes, such as response inhibition and working memory, have been extensively researched in individuals with attention deficit hyperactivity disorder (ADHD). Oculomotor neural circuits overlap extensively with regions involved in motor planning and cognition, therefore studies of oculomotor function may offer unique insights into motor and cognitive control in ADHD. We performed a series of pairwise meta-analyses based on data from 26 oculomotor studies in ADHD to examine whether there were differences in performance on visually-guided saccade, gap, antisaccade, memory-guided, pursuit eye movements and fixation tasks. These analyses revealed oculomotor disturbances in ADHD, particularly for difficulties relating to saccade inhibition, memorizing visual target locations and initiating antisaccades. There was no evidence for pursuit eye movement disturbances or saccade dysmetria. Investigating oculomotor abnormalities in ADHD may provide insight into top-down cognitive control processes and motor control, and may serve as a promising biomarker in ADHD research and clinical practice.
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Objective: To increase awareness of adult attention-deficit/hyperactivity disorder (ADHD) in the primary care community and to provide guidance for the management of this condition. Despite its increasing prevalence, adult ADHD largely remains underdiagnosed and inappropriately treated in the United States. The publication of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), has provided more clear diagnostic criteria for adult ADHD, but a solid framework supporting the transition of ADHD management from pediatric to adult primary care is lacking. Data sources: We searched PubMed and MEDLINE databases (January 1, 1984-June 1, 2016) using combinations of keywords, including ADHD, adult, diagnosis, prevalence, symptoms, treatment, comorbidity, compliance, and guidelines; international treatment guidelines; and the Diagnostic Interview for Adult ADHD websites to identify relevant clinical studies, reviews, meta-analyses, guidelines, and web-based resources describing updates to the DSM. Study selection/data extraction: In total, 143 citations were selected based on their relevance to adult ADHD diagnosis, treatment, major issues, and practice guidelines. Results: The update on diagnostic criteria in the DSM-5 may increase the diagnosis of adult ADHD. There are critical differences between childhood and adult ADHD, and specific considerations should be taken with an adult ADHD diagnosis. Adult ADHD is primarily treated with pharmacotherapy assisted by behavior interventions. Caution should be exercised when using stimulants during pregnancy and the postpartum period. Adult ADHD patients often suffer from unemployment, financial difficulties, and an unsuccessful personal life. Adult-specific guidelines may improve adult ADHD treatment. Conclusions: The successful diagnosis and management of adult ADHD require consideration of many facets including prior medical history and comorbid conditions and use of an individualized, evidence-based treatment approach.
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The prevalence of attention deficit hyperactivity disorder is about 5% of the child population, and it carries risks for mental health, educational and personal dysfunction, antisociality and death. The diagnosis in practice is made with remarkable differences in frequency between nations. Low rates in the UK, by comparison with research estimates, suggest that the condition may often be missed in clinical practice; the reasons are considered. © 2016 BMJ Publishing Group Ltd & Royal College of Paediatrics and Child Health.
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Objective: The aim of this study was to assess for the first time the criterion validity of the semi-structured Diagnostic Interview for ADHD in adults (DIVA 2.0), and its concurrent validity in comparison with the Conners' Adult ADHD Diagnostic Interview for DSM-IV (CAADID) and other ADHD severity scales, following the Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) criteria. Method: A transversal study was performed on 40 out-patients with ADHD to check the criteria and concurrent validity of the DIVA 2.0 compared with the CAADID. Results: The DIVA 2.0 interview showed a diagnostic accuracy of 100% when compared with the diagnoses obtained with the CAADID interview. The concurrent validity demonstrated good correlations with three self-reported rating scales: the Wender Utah Rating Scale (WURS; r = .544, p < .0001), the ADHD-Rating Scale (r = .720, p < .0001), and Sheehan's Dysfunction Inventory (r = .674, p < .0001). Conclusion: The DIVA 2.0 is a reliable tool for assessing and diagnosing Adult ADHD and is the only one that offers free online access for clinical and research purposes.
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Objectives: Until recently, it was believed that attention deficit and hyperactivity disorder (ADHD) are outgrown by the end of adolescence and the beginning of adulthood. The purpose of this review is to describe the characteristics of the disease in adults, depict comorbidities that accompany it, and expand the scope over methods of diagnosis and treatment of these ages. Methods: A search was conducted in the PubMed/MEDLINE database for relevant key words 'ADHD', 'attention deficit', 'hyperactivity' and 'adult'. Secondary search parameters were 'comorbid', 'prevalence', 'epidemiology', 'therapy' and 'drug therapy'. Search was limited to 'English' and 'Humans'. Results: Over the years, the persistent nature of the disorder has been clarified, elucidating prevalence rate, gender differences and subtype shifts among adult ADHD population. Nevertheless, even today, there is only limited awareness of the existence of the disorder across one's lifespan, its consequences and the appropriate treatment. Conclusions: Our results emphasise the growing awareness of adult psychosocial impairments due to ADHD symptoms and comorbidities, as well as the need for further collaboration among practitioners and mental health-care professionals to better identify the condition and allow for effective treatment.
Article
Objective: Patients with adult attention-deficit/ hyperactivity disorder (ADHD) and bipolar disorder can present with similar symptoms, including increased energy, distractibility, disorganization, impulsivity, hyperactivity, and rapid speech. Determining whether the patient has either, or possibly both, of these syndromes can be a complex task. This review attempts to clarify where these disorders overlap, both symptomatically and epidemiologically, and where they diverge, to help clinicians increase the accuracy of their diagnoses. Changes to diagnostic criteria from the fourth to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (from DSM-IV-TR to DSM-5) are discussed, as is the evidence base for pharmacological treatments. Method: Studies and sources were identified using computerized searches. Results: Adult ADHD and bipolar disorder have multiple overlapping symptoms, but there are differences in prevalence (ADHD affects 4.4% of adults in the United States versus 1.4% for bipolar disorder), onset of symptoms (usually before age 7 years in ADHD versus after age 12 years in bipolar disorder), disease course (chronic in ADHD versus cyclical in bipolar disorder), mood symptoms (absent in ADHD but always present in bipolar disorder), and psychotic symptoms (absent in ADHD but sometimes present in bipolar disorder). Approximately 20% of adult patients with ADHD also have bipolar disorder, while 10%-20% of patients with bipolar disorder have adult ADHD. Comorbidity of bipolar disorder and ADHD is associated with an earlier age of onset and a more chronic and disabling course of bipolar disorder, as well as more psychiatric comorbidity. Conclusion: Distinguishing between adult ADHD and bipolar disorder requires careful attention to phenomenology and awareness of epidemiology, with a focus on childhood history, lifetime course of symptoms, and the possibility of comorbidity.
Article
The association between attention-deficit hyperactivity disorder (ADHD) and criminality has been increasingly recognized as an important societal concern. Studies conducted in different settings have revealed high rates of ADHD among adolescent offenders. The risk for criminal behavior among individuals with ADHD is increased when there is psychiatric comorbidity, particularly conduct disorder and substance use disorder. In the present report, it is aimed to systematically review the literature on the epidemiological, neurobiological, and other risk factors contributing to this association, as well as the key aspects of the assessment, diagnosis, and treatment of ADHD among offenders. A systematic literature search of electronic databases (PubMed, EMBASE, and PsycINFO) was conducted to identify potentially relevant studies published in English, in peer-reviewed journals. Studies conducted in various settings within the judicial system and in many different countries suggest that the rate of adolescent and adult inmates with ADHD far exceeds that reported in the general population; however, underdiagnosis is common. Similarly, follow-up studies of children with ADHD have revealed high rates of criminal behaviors, arrests, convictions, and imprisonment in adolescence and adulthood. Assessment of ADHD and comorbid condition requires an ongoing and careful process. When treating offenders or inmates with ADHD, who commonly present other comorbid psychiatric disorder complex, comprehensive and tailored interventions, combining pharmacological and psychosocial strategies are likely to be needed.
Article
Neuropsychology examines the relationship between cognitive activity and corresponding cerebral conditions. At one end, psychophysics meticulously describes the details of behavior. At the other, physiology records brain cell activity during cognitive tasks. Bridging the two, neuropsychology establishes the neural correlate of behaviour when correlation methods are used, and extends to the critical neural substrate when a causal relationship can be established. Here we revisit the Hering-versus-Helmholtz controversy on binocular coordination from the psychophysician's description of combined saccade-vergence eye movements to the neurophysiological recording of motor and premotor neurons of the oculomotor neural circuitry. Whilst neo-Heringian psychophysicians and physiologists have accumulated arguments for separate saccade and vergence systems, at both the behavioral and the neural premotor levels, neo-Helmholtzians have also provided evidence for monocular programmed eye movements and commands at the premotor level. Bridging the two, we conclude that Hering and Helmholtz were both right. Importantly, the latter's viewpoint brings to the fore the importance of adaptive processes throughout life, in view of the neurobiological constraints emphasized by the former.
Article
Background: Self-rating scales and cognitive tests are instruments used in the assessment of attention-deficit hyperactivity disorder (ADHD). However, few studies have examined the differential validity of these kinds of instruments in psychiatric samples. Aims: To examine the discriminative validity of two self-report scales (ADHD Self-Report Scale [ASRS v.1.1], Current Symptom Scale [CSS]) and a continuous performance test with measures of motor activity (QBTest Plus). Methods: The interrelation between the instruments, and their abilities to differentiate between patients with an ADHD diagnosis and non-ADHD patients referred for psychiatric assessment were examined in a naturalistic sample of 61 adult patients. Results: The area under the receiver operating characteristic curve (AUC) for the dichotomized versions of the test variables in all tests ranged from 0.61 to 0.71. The ASRS and CSS exhibited sensitivity of 90.2% and 85.4%, and specificity of 35.0% and 40.0%, respectively. Variables from the QBTest Plus showed the opposite result for the variables QBImpulsivity and QBInattention, with sensitivity of 58.5% and 36.3% and specificity of 80.0% and 100.0%. Sensitivity and specificity of QBActivity were 68.3% and 65.0%, respectively. A stepwise discriminant function analysis showed that two variables from the QBTest Plus-QBInattention and QBActivity-accounted for 22.8% of the between-group variability, with the strongest predictor being QBInattention. The function yielded an overall correct classification of 72.1%. The classification correctly identified 87.8% of patients diagnosed with ADHD and 40.0% of non-ADHD patients. Conclusion: The discriminant validity of self-rating scales and the more objective measure of ADHD symptoms are poor and should be integrated generally with other sources of data.
Article
This article aims to review basic and clinical studies outlining the roles of prefrontal cortical (PFC) networks in the behavior and cognitive functions that are compromised in childhood neurodevelopmental disorders and how these map into the neuroimaging evidence of circuit abnormalities in these disorders. Studies of animals, normally developing children, and patients with neurodevelopmental disorders were reviewed, with focus on neuroimaging studies. The PFC provides "top-down" regulation of attention, inhibition/cognitive control, motivation, and emotion through connections with posterior cortical and subcortical structures. Dorsolateral and inferior PFC regulate attention and cognitive/inhibitory control, whereas orbital and ventromedial structures regulate motivation and affect. PFC circuitries are very sensitive to their neurochemical environment, and small changes in the underlying neurotransmitter systems, e.g. by medications, can produce large effects on mediated function. Neuroimaging studies of children with neurodevelopmental disorders show altered brain structure and function in distinctive circuits respecting this organization. Children with attention-deficit/hyperactivity disorder show prominent abnormalities in the inferior PFC and its connections to striatal, cerebellar, and parietal regions, whereas children with conduct disorder show alterations in the paralimbic system, comprising ventromedial, lateral orbitofrontal, and superior temporal cortices together with specific underlying limbic regions, regulating motivation and emotion control. Children with major depressive disorder show alterations in ventral orbital and limbic activity, particularly in the left hemisphere, mediating emotions. Finally, children with obsessive-compulsive disorder appear to have a dysregulation in orbito-fronto-striatal inhibitory control pathways, but also deficits in dorsolateral fronto-parietal systems of attention. Altogether, there is a good correspondence between anatomical circuitry mediating compromised functions and patterns of brain structure and function changes in children with neuropsychiatric disorders. Medications may optimize the neurochemical environment in PFC and associated circuitries, and improve structure and function.
Article
Visual attention is the mechanism the nervous system uses to highlight specific locations, objects or features within the visual field. This can be accomplished by making an eye movement to bring the object onto the fovea (overt attention) or by increased processing of visual information in neurons representing more peripheral regions of the visual field (covert attention). This review will examine two aspects of visual attention: the changes in neural responses within visual cortices due to the allocation of covert attention; and the neural activity in higher cortical areas involved in guiding the allocation of attention. The first section will highlight processes that occur during visual spatial attention and feature-based attention in cortical visual areas and several related models that have recently been proposed to explain this activity. The second section will focus on the parietofrontal network thought to be involved in targeting eye movements and allocating covert attention. It will describe evidence that the lateral intraparietal area, frontal eye field and superior colliculus are involved in the guidance of visual attention, and describe the priority map model, which is thought to operate in at least several of these areas.
Article
We recorded from neurons dorsal and dorsolateral to the third nerve nucleus of the monkey whose discharge rates modulated when the monkey tracked targets moving in depth but not when it tracked targets moving from side to side. The neurons' activity modulated equally well whether the target moved directly toward one eye or the other. For most neurons the amplitude of modulation was similar whether the monkey tracked monocularly (blur cue alone), binocularly with accommodation open-loop (disparity cue alone), or in normal binocular viewing. By comparing the modulation in normal binocular viewing with that when the blur and disparity cues were in conflict we were able to show that 19 neurons discharged in relation to the vergence response alone and not to accommodation. Eight neurons discharged exclusively in relation to accommodation. While the monkeys tracked targets moving in depth so that target vergence varied with a sinusoidal time course (frequency 0.1 or 0.2 Hz) the discharge modulations of identified vergence cells generally showed much more phase lead than expected of motoneurons. We examined the activity of a subset of these vergence cells in response to a range of stimulus frequencies to compare the dynamics of these neurons with motoneurons. The phase leads were larger than those expected of motoneurons over the entire frequency range tested. We speculate that vergence neurons may selectively activate (directly or indirectly) motoneurons with longer time constants than the mean.
Article
Animals with binocular single vision use disjunctive (vergence) eye movements to align the two eyes on a visual target. Several lines of evidence suggest that conjugate and vergence eye movement commands are generated independently and combined at the medial rectus motoneurons. If this were true, then a pure vergence eye-position signal should exist. This signal would be proportional to the horizontal angle between the eyes (vergence angle), without regard to the direction of conjugate gaze. The purpose of this experiment was to identify and study neurons that carry a pure vergence signal. Extracellular unit recordings were made from midbrain and pontine sites in monkeys trained to track visual targets moving in the horizontal, vertical, and depth (or target vergence) planes. The most commonly encountered neuron that had a vergence signal was the convergence cell. These units had a firing rate that was linearly proportional to the convergence angle; their activity was unaffected by changes in conjugate gaze. Changes in convergence cell activity preceded the change in vergence angle slightly. Convergence cell activity increased for increased convergence regardless of whether the change was in response to purely accommodative or disparity cues. Divergence cells were found far less frequently. These cells were similar to convergence cells except that they decreased their firing rate for increases in convergence. The activity of divergence cells was unaffected by changes in the direction of conjugate gaze. Both convergence and divergence cells were found, intermixed, in the mesencephalic reticular formation must outside the oculomotor nucleus. Most cells with a vergence signal were found within 1-2 mm of the nucleus. These results support the view that conjugate and vergence signals are generated independently and are combined at the extraocular motoneurons. Convergence cells seem ideally suited to provide the vergence signal required by the nearby medial rectus motoneurons.
Article
Recent studies have indicated that the superior colliculus (SC), traditionally considered to be saccade-related, may play a role in the coding of eye movements in both direction and depth. Similarly, it has been suggested that omnidirectional pause neurons are not only involved in the initiation of saccades, but can also modulate vergence eye movements. These new developments provide a challenge for current oculomotor models that attempt to describe saccade-vergence coordination and the neural mechanisms that may be involved. In this paper, we have attempted to study these aspects further by investigating the role of the rostral pole of the SC in the control of vergence eye movements. It is well-known that, by applying long-duration electrical stimulation to rostral sites in the monkey SC, saccadic responses can be prevented and interrupted. We have made use of these properties to extend this paradigm to eye movements that contain a substantial depth component. We found that electrical intervention in the rostral region also has a clear effect on vergence. For an eye movement to a near target, stimulation leads to a significant suppression and change in dynamics of the pure vergence response during the period of stimulation, but the depth component cannot be prevented entirely. When these paradigms are implemented for 3D refixations, the saccade is inactivated, as expected, while the vergence component is often suppressed more than in the case of the pure vergence. The data lead us to conclude that the rostral SC, presumably indirectly via connections with the pause neurons, can affect vergence control for both pure vergence and combined 3D responses. Suppression of the depth component is incomplete, in contrast to the directional movement, and is often different in magnitude for 3D refixations and pure vergence responses. The results are discussed in connection with current models for saccade-vergence interaction.
Article
To view objects at different distances, humans rely on vergence eye movements to appropriately converge or diverge the eyes and on ocular accommodation to focus the object. Despite the importance of these coordinated eye movements (the 'near response') very little is known about the role of the cerebral cortex in their control. As near-response neurons exist within the nucleus reticularis tegmenti pontis, which receives input from the frontal eye field region of frontal cortex, and this cortical region is known to be involved in saccadic and smooth-pursuit eye movements, we propose that a nearby region might play a role in vergence and ocular accommodation. Here we provide evidence from rhesus monkeys that a region of frontal cortex located immediately anterior to the saccade-related frontal eye field region is involved in vergence and ocular accommodation, and in the sensorimotor transformations required for these eye movements. We conclude that the macaque frontal cortex is involved in the control of all voluntary eye movements, and suggest that the definition of the frontal eye fields should be expanded to include this region.
Article
Our recent studies in non-human primates have identified and characterized cerebro-ponto-cerebellar pathways involved in the control of vergence eye movements. Specifically, within the deep cerebellar nuclei and nucleus reticularis tegmenti pontis, we have identified neurons that are related to either the near response (convergence and increased ocular accommodation) or the far response (divergence and decreased ocular accommodation). In addition, within the prearcuate region (area 8a), we have characterized neurons related not only to either the far response or the near response, but also to the sensorimotor transformations underlying these eye movements. Because the vergence-related prearcuate region abuts the frontal eye fields, we suggest that the extent of the frontal eye fields be expanded to include this region. We further suggest that with inclusion of this vergence-related region, the frontal eye fields are important for all voluntary eye movements.
Article
Results of our previous studies suggest that the circumscribed area in the rostral superior colliculus (SC) of the cat is involved in the control of accommodation. Accommodation is closely linked with vergence eye movements. In this study, we investigated whether or not vergence eye movements are evoked by microstimulation of the rostral SC in the cat. In addition, we studied the effect of chemical inhibition of the rostral SC on visually guided vergence eye movements. This study was conducted on three cats, weighing 2.5-3.5 kg. The animals were trained to carry out visually guided saccade and convergence tasks. Eye movements were measured using search coils placed on both eyes. We recorded eye movements evoked by microstimulation of the rostral SC in the alert cats. Muscimol was injected into the rostral SC, and the effect of SC inactivation on visually guided vergence eye movements was investigated. Convergence eye movements were evoked by low-current stimulation (< 30 microA) of a circumscribed area in the intermediate layers of the rostral SC on one side. Spontaneous saccades were interrupted by the stimulation of the low-threshold area for evoking convergence. Visually guided convergence eye movements were severely diminished by the injection of muscimol into the low-threshold area for evoking convergence of the SC. The rostral SC is related to the control of vergence eye movements as well as accommodation. The rostral SC may be involved in the functional linkage between accommodation, convergence and visual fixation.
Article
To examine the ability of the flicker task to demonstrate greater utility in discriminating performance in young adults with and without ADHD compared to the Conners' CPT (CCPT). Flicker task and CCPT performance were compared between an ADHD (n = 28) and control (n = 30) group of college students. This study replicated previous flicker task findings, providing support for using the flicker task to demonstrate the robust nature of change blindness. However, the flicker task did not demonstrate better discriminative utility than the CCPT. Task-dependent measures correlated with ADHD rating scale indices of inattention and hyperactivity/impulsivity, indicating that CPTs lack symptom domain specificity. Results support the growing evidence that CPTs currently provide only modest utility for discriminating performance in adults with and without ADHD. Recommendations are provided regarding the future study of CPTs as a valid measure of ADHD performance and the potential utility of the flicker task.
Manual diagnóstico y estadístico de los trastornos mentales DSM-5 [Diagnostic and sta-tistical manual of mental disorders
American Psychiatric Association. (2014). Manual diagnóstico y estadístico de los trastornos mentales DSM-5 [Diagnostic and sta-tistical manual of mental disorders] (5th ed.). Editorial Médica Panamericana.