Modulating the activity of vmPFC alters altruistic behavior: A tDCS study

Area of Science:

• Neuroscience
• Cognitive Science
• Social Psychology

Background:

• Altruistic behavior, helping others at personal cost without expectation of reward, remains a long-standing scientific question.
• Neuroimaging studies implicate the ventromedial prefrontal cortex (vmPFC) in regulating altruism, but causal evidence is limited.

Purpose of the Study:

• To establish a causal link between the vmPFC and pure altruistic behavior.
• To investigate the vmPFC's role in modulating altruistic tendencies in gain and loss contexts.

Main Methods:

• A modified dictator game with binary choices in gain and loss scenarios was employed to measure altruistic tendencies.
• Transcranial direct current stimulation (tDCS) was used to non-invasively modulate vmPFC activity.

Main Results:

• Anodal stimulation of the vmPFC significantly increased altruistic choices compared to cathodal stimulation and sham conditions.
• This effect was consistent across both gain and loss contexts.
• Participants' inferences about others' altruism correlated with their own choices, with cathodal stimulation reducing inference in the gain context.

Conclusions:

• The vmPFC plays a causal role in regulating pure altruistic behavior.
• vmPFC stimulation can directly alter decision-making in altruistic contexts.
• Understanding vmPFC function offers insights into the neural basis of prosocial behavior.