Time course of the neural activity related to behavioral decision-making as revealed by event-related potentials

Abstract

Objective: To study the time course of the electrocortical activity evoked by wins and losses in the Iowa Gambling Task (IGT), their source localizations, and their relationship with the task performance in order to achieve a better knowledge of the processes that lead to more wins than losses while the task is performed. Method: Event related potentials (ERPs) were obtained from the EEG (64-channel) of 25 participants while they performed the IGT. Source localization analyses of the ERPs were also performed. Results: ERP amplitudes were sensitive to wins and losses and also to the amount of money earned or lost. An early fronto-central negativity was elicited following feedback for both wins and losses, and its amplitude correlated with the number of wins at FCz and with both the number of wins and losses at Cz. The P200 had larger amplitude to losses and correlated positively with the number of losses. Feedback related negativity (FRN) was higher to loss trials in occipital and both left and right temporal electrodes. Frontal FRNs were more negative to loss feedback signals. Loss trials elicited larger P300 magnitudes than wins for all electrode localizations. Conclusions: All the wave components studied, but P300, were related to participants' performance in the IGT. P200 and P300 may reflect a similar process related to the conscious recognition of the error. Long-latency potentials in the time window of 500-600 ms are not related to P200 and P300. Performance data and source analysis underline the importance of the medial prefrontal cortex in loss feedback processing and in the performance of the IGT.