Steady-state visually evoked potential topography during the Wisconsin card sorting test

Area of Science:

• Neuroscience
• Cognitive Psychology
• Psychophysiology

Background:

• The Wisconsin Card Sort Test (WCS) is a neuropsychological tool used to assess executive functions.
• Understanding the neural correlates of cognitive flexibility, particularly in response to rule changes, is crucial.

Purpose of the Study:

• To investigate changes in steady-state visually evoked potential (SSVEP) topography during the performance of a computerized Wisconsin Card Sort Test (WCS).
• To identify specific brain regions involved in adapting to changing task demands within the WCS.

Main Methods:

• Recorded SSVEP from 64 scalp sites using a 13 Hz visual flicker stimulus.
• Subjects (n=16) performed a computerized WCS with automatic changes in sorting criteria.
• Analyzed SSVEP amplitude and phase lag in relation to rule change cues.

Main Results:

• A significant attenuation in SSVEP amplitude and an increase in phase lag were observed in prefrontal, central, and right parieto-temporal regions.
• These changes occurred within 1-2 seconds after the cue to change the sort criterion.
• The observed changes were specific to trials requiring a rule change, not those where the criterion remained the same.

Conclusions:

• The findings indicate dynamic changes in prefrontal and right parieto-temporal cortical activity during WCS performance.
• These brain regions show heightened activity when a change in the sorting criterion is required.
• SSVEP topography can serve as a marker for cognitive flexibility and executive function adjustments.