Wisconsin Card Sorting Test | EPFL Graph Search

The Wisconsin Card Sorting Test (WCST) is a neuropsychological test of set-shifting, which is the capability to show flexibility when exposed to changes in reinforcement. The WCST was written by David A. Grant and Esta A. Berg. The Professional Manual for the WCST was written by Robert K. Heaton, Gordon J. Chelune, Jack L. Talley, Gary G. Kay, and Glenn Curtiss. Method Stimulus cards are shown to the participant and the participant is then instructed to match the cards. They are not given instructions on how to match the cards but are given feedback when the matches they make are right or wrong. When the test was first released the method of showing the cards was done with an evaluator using paper cards with the evaluator on one side of the desk facing the participant on the other. The test takes approximately 12–20 minutes to carry out using manual scoring which is greatly reduced with the aid of computer testing. The test results produce a number of useful psychometric sc

Visual backward masking deficits in schizotypy

Daniela Herzig, Michael Herzog, Christine Mohr

In visual backward masking, a target is followed by a mask impeding target perception. Visual backward masking is a potential endophenotype for schizophrenia because patients with schizophrenia and also their unaffected relatives show significant performance deficits compared to controls. If backward masking is an endophenotype, unaffected students with elevated schizotypal traits should also show relative backward masking impairments. In the past, research on endophenotypes has mostly focused on higher cognitive functions. For this reason, we also assessed performance in the widely used Wisconsin Card Sorting Test (WCST). We tested 40 healthy undergraduate students in the visual backward masking task and the WCST used in clinical studies before. All participants filled in a self-report schizotypy measure, i.e. the O-life questionnaire assessing schizotypy along three dimensions, i.e. unusual experience, cognitive disorganization, and introvertive anhedonia. We observed that both visual backward masking and the total number of errors in the WCST were impaired for students with high scores on the cognitive disorganization dimension. No significant differences were found for introvertive anhedonia scores or unusual experience scores. The present findings indicate that both tasks are potential endophenotypes along the schizophrenia spectrum. However, previous studies indicate that the backward masking task is more reliable than higher cognitive tasks (e.g. WCST). Because our findings were specific to cognitive disorganization, we suggest that this dimension is the most illness-relevant schizotypy dimension. Our results show further evidence that visual backward masking is a potential endophenotype for schizophrenia.

2012

Visual backward masking deficits in schizotypy

Daniela Herzig, Michael Herzog, Christine Mohr

Background: In visual backward masking, a target is followed by a mask impeding target perception. Visual backward masking is a potential endophenotype for schizophrenia because patients with schizophrenia and also their unaffected relatives show significant performance deficits compared to controls. If backward masking is an endophenotype, unaffected students with elevated schizotypal traits should also show relative backward masking impairments. In the past, research on endophenotypes has mostly focused on higher cognitive functions. For this reason, we also assessed performance in the widely used Wisconsin Card Sorting Test (WCST). Methods: We tested 40 healthy undergraduate students in the visual backward masking task and the WCST used in clinical studies before (Herzog et al., 2004; Chkonia et al., 2010). The visual backward masking paradigm is based on a two-step procedure. In the first step, we presented a visual target and determined the presentation time to reach 75% correct responses for each observer individually. With this step, we compensate for general, task-irrelevant effects. In the second step, this individual duration was used to assess the actual visual backward masking performance. Here, the target was followed by a masking stimulus (5 or 25 element grating) after a blank period (ISI). All participants filled in a self-report schizotypy measure, i.e. the O-life questionnaire assessing schizotypy along three dimensions, i.e. positive schizotypy (unusual experience), cognitive disorganization, and negative schizotypy (introvertive anhedonia). Results: We observed that both visual backward masking and the total number of errors in the WCST were impaired for students with high scores on the cognitive disorganization dimension. No significant differences were found for introvertive anhedonia scores or unusual experience scores. Discussion: The present findings indicate that both tasks are potential endophenotypes along the schizophrenia spectrum. However, previous studies indicate that the backward masking task is more reliable than higher cognitive tasks (e.g. WCST) (Herzog et al., 2004; Chkonia et al., 2010). Because our findings were specific to cognitive disorganization, we suggest that this dimension is the most illness-relevant schizotypy dimension. Our results show further evidence that visual backward masking is a potential endophenotype for schizophrenia.

2012

Cognitive disorganisation in schizotypy is associated with deterioration in visual backward masking

Daniela Herzig, Michael Herzog, Christine Mohr

To understand the causes of schizophrenia, a search for stable markers (endophenotypes) is ongoing. In previous years, we have shown that the shine-through visual backward masking paradigm meets the most important characteristics of an endophenotype. Here, we tested masking performance differences between healthy students with low and high schizotypy scores as determined by the self-report O-Life questionnaire assessing schizotypy along three dimensions, i.e. positive schizotypy (unusual experiences), cognitive disorganisation, and negative schizotypy (introvertive anhedonia). Forty participants performed the shine-through backward masking task and a classical cognitive test, the Wisconsin Card Sorting Task (WCST). We found that visual backward masking was impaired for students scoring high as compared to low on the cognitive disorganisation dimension, whereas the positive and negative schizotypy dimensions showed no link to masking performance. We also found group differences for students scoring high and low on the cognitive disorganisation factor for the WCST. These findings indicate that the shine-through paradigm is sensitive to differences in schizotypy which are closely linked with the pathological expression in schizophrenia. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Elsevier2012

Visual backward masking deficits in schizotypy

Daniela Herzig, Michael Herzog, Christine Mohr

2012