In this experiment, the independent variable was the social explicit exclusion (which arises as a result of actions of other people) and social implicit exclusion (which arises as a result of an individual`s inability to participate in a common activity with other people). Activity in anterior cingulate cortex (which is associated with the experience of pain distress) and activity in the right ventral prefrontal cortex (which helps to decrease distress) were two dependent variables.
ACC is a neural “conflict monitor” which becomes active when something is wrong with an individual when an automatic response is in conflict with actual goals of a person. It was investigated previously, that ACC activity increases in the situation when a person experiences physical pain. However, it has not been examined before if ACC activity increases in the situation of psychological sufferings such as distress because of being socially rejected (Eisenberger, Lieberman& Williams, 2003).
According to results of previous studies, RVPFC takes part in the regulation of ACC. Consequently, RVPFC plays a significant role in regulation and lessening of negative affectivity, distress. For example, one study demonstrated that electrical stimulation of VPFC in rats led to decreasing of pain behavior (Eisenberger, Lieberman& Williams, 2003).
Functional MRT was used in the study as the main method of examination. Also, to obtain the information about the subjective experience of participants of the study researchers asked subjects of the experiment to write self-reports about what they experienced being social excluded.
fMRI scans had been applied to participants when they played a virtual video game with virtual (but unreal) players. There were several stages in the experiment. On the first stage, participants were excluded from the game because of technical reason (ISE), then, on the second stage, participants were included in the participation in the game. On the third stage, participants were excluded from the game by other virtual (unreal) players (ESE) (Eisenberger, Lieberman& Williams, 2003).
Results of the study demonstrated that neuroanatomical basis of social pain experience is the same as a neuroanatomical basis in experiencing physical pain. Analysis of fMRI data and information from self-reports demonstrated that there was positive correlation between perceived (self-reported distress) and an increase of ACC activity. It means that when participants experienced distress the activity of ACC became higher (Eisenberger, Lieberman& Williams, 2003).
Also, a negative connection was founded between the activity of RVPFC and self-reported distressful experience. It means that the most activated RVPFC became the lower stress were reported by participants. The negative correlational associations were found also between the activity of anterior cingulate cortex and activity of RVPFC (Eisenberger, Lieberman& Williams, 2003).
The results for situations of ESE and inclusion were compared and it was found that activity of ACC was higher in the situation of explicit social exclusion in comparison to the situation of inclusion. Results of the study also demonstrated that two areas of RVPFC – anterior cingulate and right ventral prefrontal – were more activated during the condition of ESE in comparison to inclusion-situation.
Unfortunately, researchers had not the opportunity to collect self-reports of participants immediately after the participant`s experience of implicit social exclusion. That is why researchers could analyze only the information obtained by fMRI. Results of fMRI demonstrated that activity of participants` ACC was higher during implicit social exclusion in comparison to ACC activity during the period of participants` inclusion in the game (Eisenberger, Lieberman& Williams, 2003).
However, the activity of RVPFC during inclusion and implicit social exclusion of subjects had not differed significantly. It means that self-regulation of distress of participants appeared in RVPFC when they were excluded by other players but it was absent when individuals were excluded from the game because of technical problems.
The results of the current experiment proved that words and phrases such as “hurt feelings” and other are not only metaphorical one because physical pain and psychological pain induced by the situation of rejection, social exclusion, negative feelings of being ignored and etc. have the common neuroanatomical basis and are regulated by the same center in the brain.
The study also demonstrated that emotional, psychological pain is not something abstract, invisible and absolutely subjective. Due to results of the study, it was found that emotional harm influences human`s body just like physical injuries do it.
We cannot localize psychological pain and suffering of being rejected, ignored in a particular place on our body, as we do it when we feel the physical pain, but our neuroanatomical system responses to these emotional sufferings as it a response to our physical pain experience.
Also, I think that this study demonstrated that people are disposed to suffer significantly in the situation of social exclusion. As I suppose, it proves that humans biologically predisposed to strive for association, relationships, and contacts with other people. It means that humans inclined to feel psychological discomfort (which reminds a physical pain) when they are out of a social group, social interactions, and connections.
Also, I believe that it would be interesting to examine if activation of ACC and RVPFC is the same in the situation of some financial, material fails as it is during experience of physical pain and during the experience of social rejection and exclusion.
Reference
Eisenberger, N. I., Lieberman, M. D., & Williams, K. D. (2003). Does rejection hurt? An fMRI study of social exclusion. Science, 302(5643), 290-292.
