Human brain mappingDec 22, 2017

Emotional and cooperative social interactions influence communication within and between the movement-mimicking and understanding-other-people systems

Updated Feb 9, 2026

Abstract

Strong evidence supports a model where the left posterior superior temporal sulcus (pSTS) and ventral premotor cortex (vPMC) serve as input nodes for processing social interactions.

Different neural systems are involved in understanding others' intentions, with the mirror system focusing on biological actions and the mentalizing system on abstract information.
Observing cooperative social interactions activates key nodes in the mirror system, while affective interactions activate nodes in the mentalizing system.
Effective connectivity analysis reveals that cooperativity enhances connectivity from pSTS to both the superior parietal cortex (SPL) and vPMC.
Affectivity promotes reciprocal positive connectivity between pSTS and the ventromedial prefrontal cortex (vmPFC).
These findings suggest distinct yet interconnected neural pathways for processing social interactions based on their cooperative or affective dimensions.

Simplified

Decoding the meaning of others' actions, a crucial step for social cognition, involves different neural mechanisms. While the "mirror" and "mentalizing" systems have been associated with, respectively, the processing of biological actions versus more abstract information, their respective contribution to intention understanding is debated. Processing social interactions seems to recruit both neural systems, with a different weight depending on cues emphasizing either shared action goals or shared mental states. We have previously shown that observing cooperative and affective social interactions elicits stronger activity in key nodes of, respectively, the mirror (left posterior superior temporal sulcus (pSTS), superior parietal cortex (SPL), and ventral/dorsal premotor cortex (vPMC/dPMC)) and mentalizing (ventromedial prefrontal cortex (vmPFC)) systems. To unveil their causal organization, we investigated the effective connectivity underlying the observation of human social interactions expressing increasing cooperativity (involving left pSTS, SPL, and vPMC) versus affectivity (vmPFC) via dynamic causal modeling in 36 healthy human subjects. We found strong evidence for a model including the pSTS and vPMC as input nodes for the observed interactions. The extrinsic connectivity of this model undergoes oppositely valenced modulations, with cooperativity promoting positive modulations of connectivity between pSTS and both SPL (forward) and vPMC (mainly backward), and affectivity promoting reciprocal positive modulations of connectivity between pSTS and vmPFC (mainly backward). Alongside fMRI data, such divergent effective connectivity suggests that different dimensions underlying the processing of social interactions recruit distinct, although strongly interconnected, neural pathways associated with, respectively, the bottom-up visuomotor processing of motor intentions, and the top-down attribution of affective/mental states.

Full Text

Full text is available at the source.

View Full Text ↗

Abstract

Full Text

What Lands in Your Inbox Each Week: