A group of scientists from the United States, Italy and Austria found that the ability to forgive misconduct is associated with the volume of gray matter in the anterior superior temporal groove of the brain.
Information about motives is a key factor in making moral and, in particular, judicial decisions. In different cultures, including children, it is decisive when the intentions of the subject and the consequences of the act he committed contradicted each other, for example, the harm was caused by mistake. The ability to understand such a contradiction is described within the framework of the theory of mind - it allows you to assess the beliefs of another individual and build your behavior in accordance with this assessment. According to past works, the model of the psyche is functionally connected with a nonspecific neural network, which is represented by the temporo-parietal node, the ventromedial prefrontal cortex and the temporal pole, but how morality is affected by the structural features of the brain is not well understood.
To close this gap, researchers from Harvard University, the University of Trieste and other institutions conducted an experiment with 42 healthy Italians aged 18–35 years. At the first stage, the volunteers read 36 short stories, which, depending on the motives (neutral, negative) and consequences (neutral, negative) of the actions of the actor, were conventionally divided into four categories (a total of 144 scenarios). After reading, the subjects had to make two judgments - about the moral permissibility of the behavior and the degree of guilt of the character. Subjective assessment of parameters was carried out using a visual digital seven-point scale, while throughout the experiment, the neuronal activity of the participants' brains was measured by functional magnetic resonance imaging (fMRI).
The design of the second experiment and the neural network corresponding to the model of the human psyche / Indrajeet Patil et al., Scientific Reports, 2017
Then, to identify the areas of the brain involved in attribution of the mental state, the scientists used modified Frith-Happé animations - animated videos, the characters of which are triangles of different colors. The movements of these geometrical figures imitate various scenarios of the interaction of living organisms, which makes it possible to trace the functional basis of spontaneous mentalizations, for example, in autism. In their work, the group simulated such an interaction of the big red and small blue triangles as bluff, surprise, ridicule, and others. Animations with neutral and stereotyped "behavior" of figures served as control ones. The data obtained were processed using group analysis of independent components.
Localization of the left anterior temporal sulcus and negative correlation between the volume of its gray matter and the degree of condemnation / Indrajeet Patil et al., Scientific Reports, 2017
According to the findings, in the first experiment, participants were more critical of characters who were “aware” of the negative consequences of their actions than those whose actions (including potentially harmful ones) were not based on intention or led to a neutral result. Analysis of neural activity in an experiment with animation showed that the anatomically model of the human psyche is based on the anterior and posterior cingulate cortex, dorsomedial prefrontal cortex, temporal pole, and superior temporal sulcus. It is noteworthy that the activity of these areas weakly depended on the vector of moral judgments, but the authors found a correlation between the tendency to criticize for misconduct and a decrease in gray matter in the left anterior temporal sulcus (middle temporal gyrus).
According to the researchers, the amount of gray matter in the anterior temporal sulcus can affect a person's moral judgments and the ability to understand other people's beliefs in general. So, normally, the absence of negative motives in the object of assessment serves as a weighty reason for softening judgments, but a decrease in gray matter in this area can push for more severe decisions. In the future, the results of the work are planned to be checked on a larger sample.
Promotional video:
Details of the experiments are presented in Scientific Reports.
Denis Strigun
