Human ventromedial prefrontal cortex is necessary for prosocial motivation

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Social Neuroscience

Background:

• The ventromedial prefrontal cortex (vmPFC) is implicated in decision-making, reward processing, and prosocial behavior.
• Previous functional neuroimaging studies suggest vmPFC involvement, but its causal necessity remains unclear.

Purpose of the Study:

• To investigate the causal role of the ventromedial prefrontal cortex (vmPFC) in prosocial behavior, effort-based decision-making, and reward processing.
• To determine if specific subregions of the vmPFC have distinct functions in these processes.

Main Methods:

• A study involving patients with focal vmPFC lesions (n=25), patients with lesions elsewhere (n=15), and healthy controls (n=40).
• Participants completed tasks involving choices between rest and effort to earn rewards for themselves or others.
• Voxel-based lesion mapping was used to correlate lesion location with behavioral outcomes.

Main Results:

• vmPFC damage significantly decreased prosociality, reduced earnings, and increased reward discounting based on effort.
• Patients with vmPFC lesions exerted less force when benefiting another person compared to control groups.
• Voxel-based lesion mapping revealed dissociations: medial vmPFC damage led to antisocial behavior, while lateral damage increased prosociality.
• vmPFC patients showed reduced overall effort sensitivity, with reward sensitivity localized to specific subregions.

Conclusions:

• The ventromedial prefrontal cortex (vmPFC) plays a causal role in modulating prosocial behavior and effort-based decision-making.
• Distinct subregions within the vmPFC contribute differentially to prosociality, reward sensitivity, and effort valuation.
• These findings highlight the critical necessity of the vmPFC for complex social and economic choices.