Differential hemispheric and visual stream contributions to ensemble coding of crowd emotion

Area of Science:

• Cognitive Neuroscience
• Social Psychology
• Visual Perception

Background:

• Individual facial expression recognition is well-studied, but less is known about processing emotions in group settings.
• Efficiently judging the collective mood, termed crowd emotion, is crucial in social environments where individual scrutiny is impractical.

Purpose of the Study:

• To investigate the neural mechanisms underlying crowd emotion perception.
• To determine the roles of different brain hemispheres and visual streams in processing crowd versus individual facial expressions.

Main Methods:

• Behavioral experiments and functional magnetic resonance imaging (fMRI) were employed.
• Participants performed tasks involving approaching or avoiding crowds of faces presented in different visual fields.
• Neural activity was analyzed in relation to crowd emotion perception accuracy and individual face perception.

Main Results:

• Crowd emotion perception was enhanced by goal-congruent cues and showed strong right-hemisphere lateralization.
• The dorsal visual stream, including the intraparietal sulcus and superior frontal gyrus, was preferentially activated for crowd emotion.
• The ventral stream's fusiform cortex activity correlated with individual facial expression recognition.

Conclusions:

• The brain utilizes distinct neural pathways for processing crowd emotions versus individual facial expressions.
• Crowd emotion perception relies heavily on the right hemisphere and the dorsal visual stream, supporting rapid social judgments.
• These findings highlight significant behavioral and neural differences between reading collective and individual affective states.