Perceptual aberrations, schizotypy, and the Wisconsin Card Sorting Test

Area of Science:

• Cognitive Neuroscience
• Psychiatry
• Neuropsychology

Background:

• Schizotypy is characterized by traits associated with an increased risk for psychosis, including schizophrenia.
• Executive functions, such as cognitive flexibility and set-shifting, are often impaired in individuals with schizophrenia.
• The Wisconsin Card Sorting Test (WCST) is a widely used neuropsychological tool to assess executive functions.

Purpose of the Study:

• To investigate Wisconsin Card Sorting Test (WCST) performance in schizotypal subjects compared to normal controls.
• To determine if schizotypy, measured by the Perceptual Aberration Scale (PAS), is associated with specific WCST deficits.
• To explore the relationship between schizotypy, executive function, and potential risk for psychosis.

Main Methods:

• Twenty-three schizotypal subjects (high PAS) and 28 normal control subjects (low PAS) completed the WCST.
• Schizotypy was assessed using the Perceptual Aberration Scale (PAS).
• WCST performance was analyzed for overall deficits and specific indexes, including failure-to-maintain-set and number-of-categories.

Main Results:

• Schizotypal subjects performed significantly worse on the WCST compared to control subjects.
• Deficits were observed in the failure-to-maintain-set and number-of-categories indexes among schizotypal individuals.
• Schizotypal subjects were substantially more likely to exhibit deviant WCST performance, suggesting impaired executive control.

Conclusions:

• Subtle executive function deficits on the WCST are evident in individuals with schizotypy, suggesting a potential cognitive vulnerability for psychosis.
• Findings align with theories implicating dorsolateral prefrontal cortex dysfunction and spatial working memory deficits in schizophrenia.
• The study provides hypothesis-generating results that warrant replication to confirm cognitive markers associated with psychosis risk.