1
|
Colas JT, O’Doherty JP, Grafton ST. Active reinforcement learning versus action bias and hysteresis: control with a mixture of experts and nonexperts. PLoS Comput Biol 2024; 20:e1011950. [PMID: 38552190 PMCID: PMC10980507 DOI: 10.1371/journal.pcbi.1011950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 02/26/2024] [Indexed: 04/01/2024] Open
Abstract
Active reinforcement learning enables dynamic prediction and control, where one should not only maximize rewards but also minimize costs such as of inference, decisions, actions, and time. For an embodied agent such as a human, decisions are also shaped by physical aspects of actions. Beyond the effects of reward outcomes on learning processes, to what extent can modeling of behavior in a reinforcement-learning task be complicated by other sources of variance in sequential action choices? What of the effects of action bias (for actions per se) and action hysteresis determined by the history of actions chosen previously? The present study addressed these questions with incremental assembly of models for the sequential choice data from a task with hierarchical structure for additional complexity in learning. With systematic comparison and falsification of computational models, human choices were tested for signatures of parallel modules representing not only an enhanced form of generalized reinforcement learning but also action bias and hysteresis. We found evidence for substantial differences in bias and hysteresis across participants-even comparable in magnitude to the individual differences in learning. Individuals who did not learn well revealed the greatest biases, but those who did learn accurately were also significantly biased. The direction of hysteresis varied among individuals as repetition or, more commonly, alternation biases persisting from multiple previous actions. Considering that these actions were button presses with trivial motor demands, the idiosyncratic forces biasing sequences of action choices were robust enough to suggest ubiquity across individuals and across tasks requiring various actions. In light of how bias and hysteresis function as a heuristic for efficient control that adapts to uncertainty or low motivation by minimizing the cost of effort, these phenomena broaden the consilient theory of a mixture of experts to encompass a mixture of expert and nonexpert controllers of behavior.
Collapse
Affiliation(s)
- Jaron T. Colas
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, California, United States of America
- Division of the Humanities and Social Sciences, California Institute of Technology, Pasadena, California, United States of America
- Computation and Neural Systems Program, California Institute of Technology, Pasadena, California, United States of America
| | - John P. O’Doherty
- Division of the Humanities and Social Sciences, California Institute of Technology, Pasadena, California, United States of America
- Computation and Neural Systems Program, California Institute of Technology, Pasadena, California, United States of America
| | - Scott T. Grafton
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, California, United States of America
| |
Collapse
|
2
|
Itaguchi Y, Castro-Chavira SA, Waterloo K, Johnsen SH, Rodríguez-Aranda C. Evaluation of Error Production in Animal Fluency and Its Relationship to Frontal Tracts in Normal Aging and Mild Alzheimer's Disease: A Combined LDA and Time-Course Analysis Investigation. Front Aging Neurosci 2022; 13:710938. [PMID: 35095462 PMCID: PMC8790484 DOI: 10.3389/fnagi.2021.710938] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Semantic verbal fluency (VF), assessed by animal category, is a task widely used for early detection of dementia. A feature not regularly assessed is the occurrence of errors such as perseverations and intrusions. So far, no investigation has analyzed the how and when of error occurrence during semantic VF in aging populations, together with their possible neural correlates. The present study aims to address the issue using a combined methodology based on latent Dirichlet allocation (LDA) analysis for word classification together with a time-course analysis identifying exact time of errors' occurrence. LDA is a modeling technique that discloses hidden semantic structures based on a given corpus of documents. We evaluated a sample of 66 participants divided into a healthy young group (n = 24), healthy older adult group (n = 23), and group of patients with mild Alzheimer's disease (AD) (n = 19). We performed DTI analyses to evaluate the white matter integrity of three frontal tracts purportedly underlying error commission: anterior thalamic radiation, frontal aslant tract, and uncinate fasciculus. Contrasts of DTI metrics were performed on the older groups who were further classified into high-error rate and low-error rate subgroups. Results demonstrated a unique deployment of error commission in the patient group characterized by high incidence of intrusions in the first 15 s and higher rate of perseverations toward the end of the trial. Healthy groups predominantly showed very low incidence of perseverations. The DTI analyses revealed that the patients with AD committing high-error rate presented significantly more degenerated frontal tracts in the left hemisphere. Thus, our findings demonstrated that the appearance of intrusions, together with left hemisphere degeneration of frontal tracts, is a pathognomic trait of mild AD. Furthermore, our data suggest that the error commission of patients with AD arises from executive and working memory impairments related partly to deteriorated left frontal tracts.
Collapse
Affiliation(s)
| | | | - Knut Waterloo
- Department of Psychology, UiT The Artic University of Norway, Tromsø, Norway
- Department of Neurology, University Hospital North Norway, Tromsø, Norway
| | - Stein Harald Johnsen
- Department of Neurology, University Hospital North Norway, Tromsø, Norway
- Brain and Circulation Research Group, Department of Clinical Medicine, UiT The Artic University of Norway, Tromsø, Norway
| | | |
Collapse
|
3
|
Ruchinskas R. Wechsler adult intelligence scale-4th edition digit span performance in subjective cognitive complaints, amnestic mild cognitive impairment, and probable dementia of the Alzheimer type. Clin Neuropsychol 2019; 33:1436-1444. [DOI: 10.1080/13854046.2019.1585574] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Robert Ruchinskas
- Department of Psychiatry, UT Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology & Neurotherapeutics, UT Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
4
|
Zaytseva Y, Fajnerová I, Dvořáček B, Bourama E, Stamou I, Šulcová K, Motýl J, Horáček J, Rodriguez M, Španiel F. Theoretical Modeling of Cognitive Dysfunction in Schizophrenia by Means of Errors and Corresponding Brain Networks. Front Psychol 2018; 9:1027. [PMID: 30026711 PMCID: PMC6042473 DOI: 10.3389/fpsyg.2018.01027] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 05/31/2018] [Indexed: 01/22/2023] Open
Abstract
The current evidence of cognitive disturbances and brain alterations in schizophrenia does not provide the plausible explanation of the underlying mechanisms. Neuropsychological studies outlined the cognitive profile of patients with schizophrenia, that embodied the substantial disturbances in perceptual and motor processes, spatial functions, verbal and non-verbal memory, processing speed and executive functioning. Standardized scoring in the majority of the neurocognitive tests renders the index scores or the achievement indicating the severity of the cognitive impairment rather than the actual performance by means of errors. At the same time, the quantitative evaluation may lead to the situation when two patients with the same index score of the particular cognitive test, demonstrate qualitatively different performances. This may support the view why test paradigms that habitually incorporate different cognitive variables associate weakly, reflecting an ambiguity in the interpretation of noted cognitive constructs. With minor exceptions, cognitive functions are not attributed to the localized activity but eventuate from the coordinated activity in the generally dispersed brain networks. Functional neuroimaging has progressively explored the connectivity in the brain networks in the absence of the specific task and during the task processing. The spatio-temporal fluctuations of the activity of the brain areas detected in the resting state and being highly reproducible in numerous studies, resemble the activation and communication patterns during the task performance. Relatedly, the activation in the specific brain regions oftentimes is attributed to a number of cognitive processes. Given the complex organization of the cognitive functions, it becomes crucial to designate the roles of the brain networks in relation to the specific cognitive functions. One possible approach is to identify the commonalities of the deficits across the number of cognitive tests or, common errors in the various tests and identify their common "denominators" in the brain networks. The qualitative characterization of cognitive performance might be beneficial in addressing diffuse cognitive alterations presumably caused by the dysconnectivity of the distributed brain networks. Therefore, in the review, we use this approach in the description of standardized tests in the scope of potential errors in patients with schizophrenia with a subsequent reference to the brain networks.
Collapse
Affiliation(s)
- Yuliya Zaytseva
- National Institute of Mental Health, Klecany, Czechia
- 3rd Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | | | | | - Eva Bourama
- 3rd Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | - Ilektra Stamou
- 3rd Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | - Kateřina Šulcová
- National Institute of Mental Health, Klecany, Czechia
- 3rd Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | - Jiří Motýl
- National Institute of Mental Health, Klecany, Czechia
| | - Jiří Horáček
- National Institute of Mental Health, Klecany, Czechia
- 3rd Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | | | - Filip Španiel
- National Institute of Mental Health, Klecany, Czechia
- 3rd Faculty of Medicine, Charles University in Prague, Prague, Czechia
| |
Collapse
|
5
|
|
6
|
Multiple stages of learning in perceptual categorization: evidence and neurocomputational theory. Psychon Bull Rev 2016; 22:1598-613. [PMID: 25917141 DOI: 10.3758/s13423-015-0827-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Virtually all current theories of category learning assume that humans learn new categories by gradually forming associations directly between stimuli and responses. In information-integration category-learning tasks, this purported process is thought to depend on procedural learning implemented via dopamine-dependent cortical-striatal synaptic plasticity. This article proposes a new, neurobiologically detailed model of procedural category learning that, unlike previous models, does not assume associations are made directly from stimulus to response. Rather, the traditional stimulus-response (S-R) models are replaced with a two-stage learning process. Multiple streams of evidence (behavioral, as well as anatomical and fMRI) are used as inspiration for the new model, which synthesizes evidence of multiple distinct cortical-striatal loops into a neurocomputational theory. An experiment is reported to test a priori predictions of the new model that: (1) recovery from a full reversal should be easier than learning new categories equated for difficulty, and (2) reversal learning in procedural tasks is mediated within the striatum via dopamine-dependent synaptic plasticity. The results confirm the predictions of the new two-stage model and are incompatible with existing S-R models.
Collapse
|
7
|
Perseverations in Alzheimer's disease: Memory slips? Cortex 2013; 49:2028-39. [DOI: 10.1016/j.cortex.2012.10.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 09/21/2012] [Accepted: 10/26/2012] [Indexed: 11/24/2022]
|
8
|
Environmentally enriched rearing environments reduce repetitive perseveration in caged mink, but increase spontaneous alternation. Behav Brain Res 2012; 239:177-87. [PMID: 23159704 DOI: 10.1016/j.bbr.2012.11.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 11/05/2012] [Accepted: 11/07/2012] [Indexed: 11/22/2022]
Abstract
Studies spanning 15 species (including American mink, Neovison vison) demonstrate that within similarly-housed populations, individuals displaying high levels of stereotypic behaviour (SB) typically show perseverative responding (e.g. during set-shifting, or reversal/extinction learning). Similar correlations in autism and schizophrenia suggest this indicates captivity-induced cortico-striatal circuit dysfunction. However, this pattern does not prove developmental impairment: SB, perseveration and their inter-correlations also occur in normal humans. We therefore differentially-reared enriched versus non-enriched mink to investigate whether treatments that exacerbate SB correspondingly increase perseveration (Study 1). Enriched-rearing did reduce SB and perseverative response repetition (in two-choice guessing tasks), while increasing spontaneous alternation: a strategy yielding more rewards, and suggesting enhanced hippocampal development. This complements previous research demonstrating cortical/hippocampal impairments and reduced behavioural flexibility in non-enriched animals, with implications for research animals and wild animals captive-raised for reintroduction into nature. Consistent with previous data, highly stereotypic subjects repeated guessing task responses most rapidly, suggesting disinhibition during repetition. However, unexpectedly, SB and perseveration did not co-vary across individuals. We therefore suggest that behavioural changes manifest as increased perseveration are important but do not fully explain captive animals' SBs, possible reasons including the contributory role of differential motivations for underlying source behaviours. Re-analyses of old data (Study 2) confirmed that spontaneous alternation is profitable; and demonstrated that the precise methods used for quantifying perseveration and SB can modify the strength of apparent relationships between them, as can statistically controlling for feeding motivation: as predicted, partialling out motivational effects increased the variance in SB predicted by perseveration.
Collapse
|
9
|
Boyd JK, Goldberg AE. Young children fail to fully generalize a novel argument structure construction when exposed to the same input as older learners. JOURNAL OF CHILD LANGUAGE 2012; 39:457-481. [PMID: 21729367 DOI: 10.1017/s0305000911000079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The present study exposed five-year-olds (M=5 ; 2), seven-year-olds (M=7 ; 6) and adults (M=22 ; 4) to instances of a novel phrasal construction, then used a forced choice comprehension task to evaluate their learning of the construction. The abstractness of participants' acquired representations of the novel construction was evaluated by varying the degree of lexical overlap that test items had with exposure items. We found that both child groups were less proficient than adults, but seven-year-olds showed evidence of across-the-board generalization whereas five-year-olds were sensitive to lexical overlap at test. This outcome is consistent with more conservative, item-based learning of syntactic patterns in younger children. Additionally, unlike adults and seven-year-olds, five-year-olds showed no evidence of having mastered the novel construction's linking rules. Thus, younger learners are less likely to generalize abstract argument structure constructions when exposed to the same systematic input as older learners.
Collapse
Affiliation(s)
- Jeremy K Boyd
- University of Illinois at Urbana-Champaign. Urbana, IL 61801, USA.
| | | |
Collapse
|
10
|
Haugrud N, Lanting S, Crossley M. The effects of age, sex and Alzheimer's disease on strategy use during verbal fluency tasks. AGING NEUROPSYCHOLOGY AND COGNITION 2009; 17:220-39. [PMID: 19642046 DOI: 10.1080/13825580903042700] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Clustering and switching strategies during phonemic and semantic verbal fluency tasks were investigated in healthy adults (n = 193, 86 males, 20-90 years) in young, middle-aged, young-old, and old-old age groups (Study 1). Older groups produced fewer total words and lower switching scores; males relied more on clustering and females on switching to produce equivalent output. In Study 2, early Alzheimer's disease participants, compared to healthy older adults, (n = 26 per group) produced fewer total words and smaller average clusters. Sex, age, and clinical differences on switching and clustering strategies support a dual processing model of verbal fluency.
Collapse
Affiliation(s)
- Nicole Haugrud
- Department of Psychology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
| | | | | |
Collapse
|
11
|
Abstract
BACKGROUND Clinical trials yield discrepant information about the impact of hormone therapy on verbal memory and executive function. This issue is clinically relevant because declines in verbal memory are the earliest predictor of Alzheimer's disease and declines in executive function are central to some theories of normal, age-related changes in cognition. METHODS We conducted a systematic review of randomized clinical trials of hormone therapy (i.e. oral, transdermal, i.m.) and verbal memory, distinguishing studies in younger (i.e. <or=65 years of age; n = 9) versus older (i.e. >65 years; n = 7) women and studies involving estrogen alone versus estrogen plus progestogen. Out of 32 placebo-controlled trials, 17 were included (13 had no verbal memory measures and 2 involved cholinergic manipulations). We also provide a narrative review of 25 studies of executive function (two trials), since there are insufficient clinical trial data for systematic review. RESULTS There is some evidence for a beneficial effect of estrogen alone on verbal memory in younger naturally post-menopausal women and more consistent evidence from small-n studies of surgically post-menopausal women. There is stronger evidence of a detrimental effect of conjugated equine estrogen plus medroxyprogesterone acetate on verbal memory in younger and older post-menopausal women. Observational studies and pharmacological models of menopause provide initial evidence of improvements in executive function with hormone therapy. CONCLUSIONS Future studies should include measures of executive function and should address pressing clinical questions; including what formulation of combination hormone therapy is cognitively neutral/beneficial, yet effective in treating hot flashes in the early post-menopause.
Collapse
Affiliation(s)
- Pauline M Maki
- Neuropsychiatric Institute, MC 913, University of Illinois at Chicago, 912 South Wood Street, Chicago, IL 60612, USA.
| | | |
Collapse
|
12
|
Pekkala S, Albert ML, Spiro A, Erkinjuntti T. Perseveration in Alzheimer's disease. Dement Geriatr Cogn Disord 2008; 25:109-14. [PMID: 18075249 DOI: 10.1159/000112476] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/20/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS AND METHODS Perseveration is common in Alzheimer's disease (AD). We document the type and quantitative burden of perseveration as cognitive decline progresses from normal aging (n = 30) through mild AD (n = 20) to moderate AD (n = 20) by administering a semantic verbal fluency task. RESULTS We found perseveration to increase significantly with increasing severity of AD and different types of perseveration that distinguish the subject groups in a statistically significant manner. Recurrent and continuous perseverations appear early in AD. As the disease progresses in severity into moderate stage, the number of recurrent and continuous perseverations increases, and stuck-in-set perseverations emerge. CONCLUSION The different types of perseveration are likely to reflect the progressive deterioration of different brain regions in AD.
Collapse
Affiliation(s)
- S Pekkala
- Department of Speech Sciences, University of Helsinki, Helsinki, Finland.
| | | | | | | |
Collapse
|
13
|
Joffe H, Hall JE, Gruber S, Sarmiento IA, Cohen LS, Yurgelun-Todd D, Martin KA. Estrogen therapy selectively enhances prefrontal cognitive processes: a randomized, double-blind, placebo-controlled study with functional magnetic resonance imaging in perimenopausal and recently postmenopausal women. Menopause 2006; 13:411-22. [PMID: 16735938 DOI: 10.1097/01.gme.0000189618.48774.7b] [Citation(s) in RCA: 176] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Estrogen therapy (ET) seems to differentially effect cognitive processes in younger versus older postmenopausal women, suggesting a window of opportunity when ET is most beneficial. Cognitive improvement in younger postmenopausal women has been attributed to ET's influence on hot flushes and sleep, but empiric examination of the mediating role of menopause symptoms versus direct effects of ET on the brain is limited. DESIGN In a double-blind trial, 52 women were randomly assigned to estradiol 0.05 mg/day (n = 26) or placebo transdermal patches (n = 26) for 12 weeks. Women completed tests of memory, learning, and executive functioning, and hot flush and sleep assessments at baseline and study end. A subset of women (five ET treated, six placebo treated) also underwent blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) studies. RESULTS Nondepressed perimenopausal and postmenopausal women were studied. The majority had hot flushes and sleep impairment. Compared with placebo, ET selectively reduced errors of perseveration during verbal recall (P = 0.03), a frontal system-mediated function, but did not influence other cognitive processes. Women with baseline hot flushes had greater cognitive benefit with ET (P < 0.05). Cognitive benefit was not associated with sleep problems or its improvement. Measures of fMRI BOLD activation during tests of verbal and spatial working memory showed significant increases in frontal system activity with ET (P < 0.001). CONCLUSIONS Estrogen therapy selectively improves executive functioning as demonstrated by reduced perseverative errors and prefrontal cortex activation during verbal recall tasks. Cognitive improvement with ET is associated with hot flushes, but not with sleep, suggesting that ET has a direct central nervous system effect, rather than an indirect effect mediated through improvement of sleep.
Collapse
Affiliation(s)
- Hadine Joffe
- Women's Center for Behavioral Endocrinology, McLean Hospital, Harvard Medical School, Boston, MA, USA.
| | | | | | | | | | | | | |
Collapse
|
14
|
Moses MS, Nickels LA, Sheard C. I'm sitting here feeling aphasic! A study of recurrent perseverative errors elicited in unimpaired speakers. BRAIN AND LANGUAGE 2004; 89:157-173. [PMID: 15010247 DOI: 10.1016/s0093-934x(03)00364-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/26/2003] [Indexed: 05/24/2023]
Abstract
In this study, the recurrent perseverative errors produced by 44 speakers without impairment were examined in picture naming and reading aloud tasks under a fast response deadline. The proportion of perseverative relative to non-perseverative errors was greater in picture naming, the more error-prone task, than in reading aloud. Additionally, although perseverative errors were less likely to be related to the target than non-perseverative errors, the overall distribution of perseverative and non-perseverative errors in each task was similar. It is concluded that the perseverative errors produced by the participants reflected both the degree and level at which language processing efficiency was reduced in each task. This is consistent with a more recent account of perseveration as a result of normally existing persistent activation overcoming weakened activation of a target at any level of language processing. These results are compared with recent studies of recurrent perseverative errors produced by people with aphasia in light of the cognitive neuropsychological assumption that speakers with and without impairment utilise a common language processing system.
Collapse
|
15
|
Abstract
Letter and semantic fluency tasks are often used in neuropsychological assessment and are sensitive to many conditions. Performance is assessed by correct responses and errors, including perseverations. Healthy young adults performed letter and semantic fluency tasks. One group performed these tasks in the conventional manner; 2 other groups performed them while maintaining memory loads. The memory loads consisted either of words from the same category as the fluency task or of words from a different category. The results showed little effect of memory loads on correct responses but significant effects of memory load on perseveration rates: Same-category loads resulted in higher rates, especially in letter fluency. The results are discussed in terms of frontal lobe function in verbal fluency.
Collapse
|
16
|
Love JM, Greve KW, Sherwin E, Mathias C. Comparability of the Standard WCST and WCST–64 in Traumatic Brain Injury. ACTA ACUST UNITED AC 2003; 10:246-51. [PMID: 14690806 DOI: 10.1207/s15324826an1004_7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The aim of this study was to investigate the comparability of the Wisconsin Card Sorting Test short form (WCST-64) to the standard form in a clinical population with documented brain pathology: chronic severe traumatic brain injury (TBI). Participants were 61 patients at least 1 year after severe TBI living at a large residential rehabilitation facility. The WCST was administered in standard fashion with both the standard and 64-card versions scored. All derived scores with norms were examined. Results indicated that the WCST-64 scores were comparable to the standard version, and assigned impairment levels remained relatively stable. These results suggest the WCST-64 is a valid alternative to the standard version in chronic severe TBI.
Collapse
Affiliation(s)
- Jeffrey M Love
- Department of Psychology, University of New Orleans, Louisiana 70148, USA
| | | | | | | |
Collapse
|