Brain region governing helping behavior identified

Summary: A new study has found that the ventromedial prefrontal cortex (vmPFC) is crucial for prosocial behaviors. Researchers studied patients with brain injuries and found that damage to the vmPFC reduced the willingness to help others.

Understanding the role of this brain region could improve treatments for social interaction disorders and motivate global problem-solving efforts.

Highlights:

• Researchers have identified the ventromedial prefrontal cortex (vmPFC) as crucial for prosocial behaviors.
• The study included patients with vmPFC lesions, other brain lesions, and healthy controls.
• Damage to the vmPFC reduced willingness to help others and physical effort exerted.

Source: University of Birmingham

Our willingness to help others is governed by a specific brain region identified by researchers in a study of patients with brain damage in this region.

Knowing where in the brain “useful” decisions are made is important to understanding how people might be motivated to tackle major global challenges, such as climate change, infectious diseases and international conflict. It is also essential for finding new approaches to treating social interaction disorders.

The study, published in Human behaviorwas carried out by researchers at the University of Birmingham and the University of Oxford and shows for the first time how a region called the ventromedial prefrontal cortex (vmPFC) plays a vital role in helping or “prosocial” behaviors. .

Lead author Professor Patricia Lockwood said: “Prosocial behaviors are essential to tackling global challenges. Yet helping others often takes effort, and humans are reluctant to put in effort. Understanding how helping decisions are processed in the brain is extremely important.

In the study, researchers focused on the vmPFC, a region just at the front of the brain known to be important for decision-making and other executive functions.

Previous studies using magnetic resonance imaging (MRI) have linked the vmPFC to choices involving a trade-off between available rewards and the effort required to obtain rewards. However, these techniques cannot show whether any part of the brain is essential for these functions.

Three groups of participants were recruited for the study. 25 patients had vmPFC lesions, 15 patients had lesions elsewhere in the brain, and 40 people were healthy, gender-matched control participants. These groups allowed researchers to specifically test the impact of damage to the vmPFC.

Each participant took part in an experiment in which they met another person anonymously. They then completed a decision-making task that measured the extent to which they were willing to exert physical effort (by squeezing a grip strength device) to earn rewards (bonus money) for themselves and each other person.

By allowing participants to meet – but not see – the person they were “working for” in advance, the researchers were able to give the impression that participants' efforts would have real consequences, but hide any information about the other person. person who could affect the decision. manufacturing.

Each choice participants made varied depending on the amount of bonus available to them or the other person and how much force they would have to exert to get the reward. This allowed researchers to measure the impact of reward and effort separately, and use advanced mathematical modeling to accurately quantify individuals' motivation.

The study results clearly showed that the vmPFC was necessary for motivation to help others. Patients with vmPFC lesions were less willing to choose to help others, exerted less force even after deciding to help, and earned less money for helping others than control groups.

In a later step, the researchers used a technique called lesion symptom mapping that allowed them to identify even more specific subregions of the vmPFC where damage made people particularly antisocial and unwilling to make effort to protect themselves. 'other person. Surprisingly, the damage caused to a neighboring but different subregion made people relatively more willing to help.

Dr Jo Cutler, co-senior author, said: “As well as better understanding prosocial motivation, this study could also help us develop new treatments for clinical disorders such as psychopathy, where understanding the neural mechanisms underlying -currents can give us new information on how to process. These conditions. »

“This region of the brain is particularly interesting because we know that it undergoes late development in adolescents, and also changes with age,” added Professor Lockwood.

“It will be really interesting to see if this area of ​​the brain can also be influenced by education: can we learn to help others better? »

About this behavioral neuroscience research news

Author: Beck Lockwood
Source: University of Birmingham
Contact: Beck Lockwood – University of Birmingham
Picture: Image is credited to Neuroscience News

Original research: Free access.
“The human ventromedial prefrontal cortex is necessary for prosocial motivation” by Patricia Lockwood et al. Human behavior

Abstract

The human ventromedial prefrontal cortex is necessary for prosocial motivation

The ventromedial prefrontal cortex (vmPFC) is essential for decision-making. Functional neuroimaging links the vmPFC to the processing of rewards and effort, while parallel work suggests the involvement of the vmPFC in prosocial behavior.

However, the necessity of vmPFC for these functions is unknown. Patients with rare focal lesions of vmPFC (not= 25), patients with lesions elsewhere (not= 15) and healthy controls (not= 40) chose between resting and putting in effort to earn rewards for themselves or another person. vmPFC damage decreased prosociality across both behavioral and computational measures.

vmPFC patients gained less, reduced effort rewards more, and exerted less force when another person benefited, compared to both control groups. Voxel-based lesion mapping revealed dissociations between vmPFC subregions.

While medial lesions led to antisocial behavior, lateral lesions increased prosocial behavior compared to patients with lesions elsewhere. vmPFC patients also showed reduced overall exercise sensitivity, but reward sensitivity was limited to specific subregions.

These results reveal multiple causal contributions of the vmPFC to prosocial behavior, effort, and reward.