【Abstract】Compared with an offline context, the sources of online review are typically unknown, with more variable opinions from multiple individuals. This variability can make it difficult for consumers to judge the consensus of others’ views using only direct social clues. However, few studies have focused on the brain’s processing of mixed opinions in an online context. In this study, an experiment that involved voting on the helpful- ness of online reviews was designed to investigate how participants processed their personal views alongside others’ views. A total of 32 participants were asked to decide whether each online review was helpful and were then given feedback regarding how many people found each review helpful. Participants’ voting behaviors and conformity feedback-related event-related brain potentials (ERPs) were recorded and analyzed. Participants rated positive reviews as more helpful than negative reviews. Response times were longer when participants evaluated negative reviews. Therefore, the nega- tivity bias of reviews may not result from the review’s helpfulness but rather from the cognitive processing involved in the evaluation of the reviews. Further ERP analysis showed that the incongruence of participants’ choices with the relative majority opinion generated from a ranking of a review’s helpfulness elicited more negative-going feedback-related negativity and less positive-going P300 than did the condition of their choices’ congruence with the relative majority opinion. This finding suggests that incongruence with the relative majority opinion was processed as negative feedback due to expectation violation, whereas congruence with the relative majority opinion was processed as positive feedback for conformity. Furthermore, the feedback-related negativity response elicited by the trials of inconsistency with relative majority opin- ions during the early period was smaller than that in the later period, whereas the P300 response elicited by the trials of consistency with relative majority opinions in the early period was greater than that in the later period. The ERP results suggest that even in an online context, the brain can automatically encode the relative majority opinion by learning from a comparison of other visible social cues, and automatically categorize whether one’s personal views are consistent with those of the relative majority.

【Keywords】 online review helpfulness, social judgment, negativity bias, relative majority,

event-related potential

本文发表在SSCI期刊Journal of Neuroscience, Psychology, and Economics，2019, 12(2)。