An ERP study on the role of instant purchasing group quantity in e-commerce live streaming: a social impact perspective

E-commerce live streaming has been increasingly prevalent in the online shopping environment, yet the instant purchasing group quantity as a crucial element in e-commerce live streaming has not gained in-depth investigation. Drawing on the social impact theory, this paper adopted event-related potential (ERP) to explore the role of instant purchasing group quantity in e-commerce live streaming and the underlying psychological mechanisms through a panic buying task. Behaviorally, consumers exhibited a shorter response time (RT) for panic buying when the instant purchasing group quantity was high (HQ) compared to when the instant purchasing group quantity was low (LQ). At the neural level, a significantly greater P2 amplitude (reflecting early automatic attention allocation) was triggered by success feedback versus failure feedback in the LQ condition but not in the HQ condition. We also found larger FRN difference (reflecting middle prediction errors and affective evaluation) between failure and success feedbacks of panic buying under the LQ condition compared to the HQ condition. However, the P3 difference (reflecting late valence evaluation) between success and failure feedbacks did not significantly vary under the LQ and HQ conditions. These ERP results indicated that P2 and FRN could reflect the social impact effect of instant purchasing group quantity, while P3 could not. The above findings demonstrated a two-phase mechanism behind the influence of social impact on consumer behavior, which means that the social impact has an effect on consumers' attention allocation in the first phase and their affections in the second phase, ultimately influencing their behavior.