Time window for cognitive activity involved in emotional processing

Background: From previous studies it is becoming evident that the processing of unpleasant stimuli occurs early (0 to 300 ms); however, it is not clear how cognitive processing related to pleasant/unpleasant emotions occurs at later time windows (>= 300 ms). On the other hand, as evident from the previous reports, BIS and BAS personality traits are strongly associated with unpleasant and pleasant responses, respectively. Therefore, in the present study, we aim to identify the time window involved in human pleasant/unpleasant emotional processing by investigating ERP components correlated with BIS/BAS personality traits. Methods: Twenty-nine men took part in the study and recording ERP during presented sounds. BIS/BAS score was calculated using the Japanese edition of the BIS/BAS questionnaire. Results: Significant correlation was not observed between BIS and BAS scores. A significant and positive correlation was observed between N100 amplitude and BIS score. A positive correlation was found between BAS fun seeking subscale score and LPP amplitude. Our findings did not contradict previous study results. Conclusions: Our results suggest that the processing of unpleasant emotions takes place early on, since N100 response was larger in high BIS subjects who are known to be sensitive to unpleasant emotions. LPP was larger in high BAS subjects who are known to be sensitive to pleasant emotions. The LPP was considered to be augmented because the ACC activity level during pleasant emotions reflected on LPP.