Dyadic similarity in social value orientation modulates hyper-brain connectivity in interaction

823 

Abstract Submission 

Hanxuan Zhao¹, Sihua Xu²

¹Shanghai International Studies University, Shanghai, China, ²School of Business and Management, Shanghai International Studies University, Shanghai, China

Hanxuan Zhao  
Shanghai International Studies University
Shanghai, China

Sihua Xu  
School of Business and Management, Shanghai International Studies University
Shanghai, China

As the inherent inclination towards distributing resources between oneself and others in situations of interdependence, the social value orientation (SVO) has been viewed as the crucial personality in the social interaction(Zhao et al., 2023). However, whether dyadic similarity in SVO would affect the real-time interpersonal interaction and the underlying intra-brain and inter-brain mechanism still remained unknown.

With the functional near-infrared spectroscopy (fNIRS) – based hyperscanning technique, the present study examined the hyper-brain functional connectivity pattern underlying the effect of the dyadic similarity in SVO on the interpersonal interaction during the button pressing task(Cui et al., 2012). Using the Social Value Orientation (SVO) slider measure, we recruited 88 participants forming 44 dyad (22 prosocial-prosocial dyads, 22 proself-proself dyads). The cooperation index and the competition index in the i trial were respectively denoted as follows.
Competition Index= |RT_(1,i)-RT_(2,i) |×(RT_(1,i)+RT_(2,i))
Cooperation Index= |RT_(1,i)-RT_(2,i) | / (RT_(1,i)+RT_(2,i))
Adopting the prefrontal cortex (PFC) as the targeted brain region, the intra-brain functional connectivity (FC) and the inter-brain synchronization (INS) among different regions of interest (ROIs) were assessed using the cross-correlation between oxyhemoglobin (HbO) concentration time series according to the existing studies.

Our behavioral results reported that the competition index in the proself-proself (SS) group was significantly lower than that in the prosocial-prosocial (CC) group (t [42] = -2.21, p < 0.05), demonstrating more intense competition in the SS group. It was also found that the cooperation index in the proself-proself (SS) group was significantly higher than that in the prosocial-prosocial (CC) group (t [42] = 2.82, p < 0.01), demonstrating more cooperative performance in the CC group.
Our intra-brain functional connectivity results reported significant interaction effect of BLOCK × SVO SIMILARITY in the FC between left superior frontal gyrus (lSFG) and right frontopolar cortex (rFPC) (F [1, 42] = 14.26, FDR-corrected p < 0.05). In the SS group, the FC of lSFG – rFPC in the cooperation block were significantly higher than that in the competition block. In the CC group, the FC of lSFG – rFPC in the competition block was significantly higher than that in the cooperation block.
Our inter-brain synchronization results showed significant interaction effect of BLOCK × SVO SIMILARITY in the FC between right frontopolar cortex (rFPC) and left middle frontal gyrus (lMFG) (F [1, 42] = 13.58, FDR-corrected p < 0.05). In the SS group, the FC of rFPC – lMFG in the competition block were significantly higher than that in the cooperation block. In the CC group, the FC of rFPC – lMFG in the cooperation block was significantly higher than that in the competition block.

Taken together, the present study uncovered the distinct hyper-brain functional connectivity patterns underlying the effect of the dyadic similarity in SVO on the interpersonal cooperation and competition.

Social Interaction ¹

NIRS ²

Near Infra-Red Spectroscopy (NIRS)

Other - social interaction;hyper-brain connectivity;social value orientation