Influence of design interaction modes on conceptual design behavior and inter-brain synchrony in designer teams: A fNIRS hyperscanning study

Conceptual design is inherently a social and creative activity. Most studies on conceptual design of designer teams focused primarily on behavioral aspects, leaving cross-brain coupling neural mechanisms underlying designer teams’ collaboration unexplored. Investigating inter-brain synchrony (IBS) offers a critical perspective on how shared neural activity supports key collaborative processes, such as coordination, communication, and team creativity. This study investigated the effects of design interaction modes (face-to-face vs. remote virtual vs. electronic brainstorming; FTF vs. RV vs. EBS) on designer teams’ interactive behaviors and IBS during conceptual design. Using fNIRS-based hyperscanning, neural activities in the right prefrontal cortex and right temporoparietal junction (r-TPJ) were recorded for 72 designers (36 dyads), and behavioral characteristics, IBS, and temporal dynamics of these metrics across modes were analyzed. Results showed that FTF teams outperformed RV and EBS in creative design performance, cooperation level, team flexibility, perspective-taking, and turn-taking. Creative design performance and cooperation level increased over time across all modes, particularly in FTF and RV, while team flexibility, perspective-taking, and turn-taking initially rose before declining, notably in FTF and RV. fNIRS data revealed greater IBS in r-TPJ and between r-TPJ and right dorsolateral prefrontal cortex (r-DLPFC) in RV compared to FTF and EBS, both following a U-shaped temporal trend. Cooperation level, perspective-taking, and turn-taking positively correlated with △IBS in r-TPJ, while cooperation level correlated with △IBS between r-TPJ and r-DLPFC. These results highlight distinct behavioral and neural synchronization patterns across interaction modes in designer teams during conceptual design process, with FTF mode performing best. These findings enhanced understanding of designer teams’ interactive cognition, contributed to design neurocognition research, and offered practical implications for designing tools and training programs to optimize team performance.