Impairment of prosocial sentiments is associated with frontopolar and septal damage in frontotemporal dementia

    This brain lesion study sought to provide evidence that patients with damage to their frontopolar cortex and septal areas show less prosocial behavior than control participants. Prosocial behavior is defined as behavior that lets us care about others and that causes us to dislike making mistakes (e.g. guit, pity, and embarrassment). Researchers used a moral sentiment task, which consisted of 98 scenarios, each accompanied by a choice of 4 adjectives that the participants had to choose to indicate how the scenario would make them feel (see figure). Behavioral data was recorded (i.e. the participants’ choices to the questions in each of the 98 scenarios), and imaging was acquired with a PET scanner. Behavioral results indicated that participants with lesions to their frontopolar cortex and septal areas showed less prosocial behavior and other critical sentiments than controls, and they showed frontotemporal and subcortical hypometabolism, which was predicted.
    In my opinion, this study’s primary strength was that they ruled out the possibility for an alternative hypothesis, that the relationship between FPC-septal hypometabolism and reduced prosocial sentiments in lesion patients was simply due to overall emotional blunting. Even after controlling for other types of emotions, the relationship between FPC-septal hypometabolism and reduced prosocial sentiments remained robust. I think it is extremely important to study prosocial sentiment because of the role it plays in our everyday functioning and our ability to interact with a multitude of other individuals. Those who lack prosocial behavior (i.e. sociopaths, those with developmental delays like autism, etc.) may lack it because of structural differences in the FPC and septal areas of their brains.


 Moll, J., Zahn, R., de Oliveira-Souza, R., Bramati, I., Krueger, F., Tura, B., Cavanagh, A., Grafman, J. Impairment of prosocial sentiments is associated with frontopolar and septal damage in frontotemporal dementia. Neuroimage 54 (2011), 1735-1742.