Affective ambiguity for a group recruits ventromedial prefrontal cortex

Area of Science:

• Neuroscience
• Social Psychology
• Cognitive Neuroscience

Background:

• Affective neuroimaging often uses single faces, limiting generalizability to complex social settings.
• Processing ambiguous group affect is crucial for social appraisal but understudied.
• The medial prefrontal cortex (PFC) is implicated in processing ambiguous affective stimuli.

Purpose of the Study:

• To investigate neural responses to complex, ambiguous affective stimuli using a novel task.
• To probe the medial prefrontal cortex (PFC) during the appraisal of group affective displays.
• To examine the role of ventromedial PFC in processing ambiguous social affect.

Main Methods:

• Functional MRI (fMRI) was used with 27 healthy volunteers.
• The Wall of Faces (WOF) task presented matrices of faces with ambiguous or unambiguous emotional/gender distributions.
• Participants made "more angry/happy" or "more male/female" decisions.

Main Results:

• Ambiguous vs. unambiguous trials activated conflict monitoring regions (dorsal ACC, dorsolateral PFC, parietal cortex).
• Ambiguous affective decisions (vs. ambiguous gender decisions) showed greater activation in ventromedial PFC (including ventral ACC).
• This supports a functional dissociation between dorsal (cognitive) and ventral (affective) ACC divisions.

Conclusions:

• Ventromedial PFC plays a critical role in appraising affective tone in complex, multi-face displays.
• The findings support a distinct role for ventromedial PFC in social affective processing.
• The study highlights the importance of using complex stimuli in affective neuroimaging research.