Learning proficiency on the Wisconsin Card Sorting Test in people with serious mental illness: what are the cognitive characteristics of good learners?

Although it is widely accepted that schizophrenia and other serious mental illnesses (SMI) are associated with neurocognitive difficulties, there is great variability in neurocognitive functioning across individuals. In recent years, a growing number of schizophrenia studies have utilized the concept of learning potential to explore individual variation in cognition. Learning potential refers to the ability to benefit from instruction and is measured by assessing test performance before and after training. The present study was intended to explore the cognitive characteristics associated with learning potential in people with serious mental illness. Sixty individuals with schizophrenia, bipolar or major (unipolar) depression completed a learning potential assessment using the Wisconsin Card Sorting Test (WCST) and a battery of standard cognitive measures. Based on established criteria for WCST learner subgroups, participants were categorized as high achievers, learners or non-retainers. There were several significant cognitive differences among the three learner subgroups. Most notably, individuals who were categorized as learners on the WCST showed significantly better verbal and working memory compared to non-retainers. Secondary analyses revealed that the three SMI diagnostic groups (depression, bipolar, schizophrenia) were similar in learning potential and did not differ on any of the standard cognitive measures. This study provides support for learning potential classification in schizophrenia as well as other serious mental illnesses, and indicates that learning potential may specifically be related to verbal and working memory abilities.