Event-related potential correlates of extradimensional and intradimensional set-shifts in a modified Wisconsin Card Sorting Test

Event-related potentials (ERPs) were recorded in healthy adult participants during the performance of a modified version of the Wisconsin Card Sorting Test that was designed to isolate the effects of extradimensional (ED) and intradimensional (ID) set-shifts. ERP averages were created for ED- and ID-Shift trials, as well as for the 5th trial in each block (Maintain-Rule). Differences in sensory and longer latency ERP components were found between the ED- and ID conditions, and between the two shift conditions and the Maintain-Rule trials. Consistent with the previous literature, these data indicated that ED- and ID-Shifts require different levels of neural resources. A secondary goal of this experiment was to use the excellent temporal resolution of ERPs to examine the neural correlates of various other aspects of the performance of a set-shift task, including differences between correct shifts and the commission of errors, and the differences between the reception of correct and error feedback. Comparisons were made between ERP averages to correct ED-Shift trials and ED-Error trials, and to feedback following a correct ED-Shift compared to feedback following an error. As expected, ERP differences were found between correct trials and error trials, and between the ERP correlates of receiving different types of feedback. Overall, these data further indicate the utility of using ERP methodology to study various aspects of complex neuropsychological paradigms.