Neural mechanisms underlying the effect of differential encoding on collaborative retrieval: Evidence from fNIRS

The present study aimed to investigate the effects and neural mechanisms of different encoding level combinations on collaborative memory retrieval and post-collaborative individual memory. An experimental method was adopted, recruiting 160 healthy undergraduate students as participants. Collaborative groups consisted of dyads, with 40 participants (20 pairs) assigned to each of the three encoding combinations; additionally, 20 participants each from the semantic and perceptual encoding conditions were randomly paired to form matched nominal groups. Experimental materials consisted of standardized two-character word lists presented via E-Prime software, with synchronized fNIRS data collection. The study selected the prefrontal cortex (PFC) and the right temporoparietal junction (rTPJ) as regions of interest (ROIs). A configuration of 8 sources and 12 detectors formed 24 measurement channels, with 17 channels (1–17) located in the PFC and 7 channels (18–24) in the rTPJ. During the encoding phase, all participants underwent either semantic or perceptual encoding processing. In the retrieval phase, collaborative dyads formed three combinations (Semantic + Semantic, Perceptual + Perceptual, and Semantic + Perceptual) to perform collaborative retrieval and subsequent individual retrieval, while nominal groups performed tasks independently throughout the procedure. Data collection encompassed the number of correct and incorrect responses during collaborative retrieval and secondary individual retrieval, as well as fNIRS hyperscanning data. The overall dataset comprises three subsets: data_1 contains collaborative retrieval performance, including the accuracy of collaborative retrieval; data_2 contains secondary individual retrieval performance, including the accuracy of secondary individual retrieval; and data_3 contains hyperscanning data, covering inter-brain synchrony (IBS) data across all channels. This dataset comprehensively presents the dynamic effects and neural characteristics of different encoding combinations on collaborative memory.