Medial Prefrontal Cortex Involved in the Neural Representation of Individual Social Networks and Loneliness

by | Jul 14, 2020 | 2020, Brain Health

Written by Angeline A. De Leon, Staff Writer. This study explores how the social brain reflects our attachments to people and why lonely people feel disconnected from others. 

depression - brain healthInnate to human well-being is the ability to socially connect with others. Evidence in psychological research supports this notion, with studies suggesting that interpersonal connection is not only helpful in promoting well-being 1,2, but that a lack thereof may constitute a serious risk to mental and physical health 3,4. At the neural level, the medial prefrontal cortex (MPFC) is involved in the representation of self, as well as close personal connections 5, showing stronger activation in response to those who share deeper personal similarities to us 6. Neuroscience research suggests that the MPFC may accomplish this representation of self-other in one of two ways: by maintaining a structured map of our objective social networks 7 or by cataloging social contacts based on their similarity to our own self-representation 8. Based on this, a question of interest pertains to loneliness (defined as perceived social isolation) and whether its manifestation is accompanied by alterations in the neural representation of one’s social network or perhaps a “lonelier” neural representation of self (based on lower perceived similarities to others). To explore these possibilities in relation to the MPFC, researchers at Stanford University and Dartmouth College conducted a neuroimaging study 9 (2020) to examine the structure of self-other representation in the brain.

A total of 43 participants (30 females, 13 males; mean age = 20.2 years) completed a functional magnetic resonance imaging (fMRI) scan during which they performed a self-other reflection task. Here, subjects were instructed to make trait judgements (friendly, polite, amusing, etc.) on 1) themselves, 2) five close members of their social network, 3) five acquaintances, 4) and five well-known celebrities. Following the scan, subjects also rated their subjective closeness to each of the targets and completed the Revised UCLA Loneliness Scale. Whole-brain analysis of fMRI data was carried out, as well as a region-of-interest analysis specific to the MPFC.

Neuroimaging analyses revealed differential activation of the MPFC in response to the self vs. all other targets, with the representation of others being further categorized into two different groups: one pertaining to social network members (collapsing across close connections and acquaintances) and the other pertaining to celebrities. The magnitude of MPFC activation also showed a linear increase according to the subjective degree of participants’ social closeness to the target (β = 0.13, t (43) = 5.67, p < 0.001). There was also significantly greater overlap in the neural representation of the self in the MPFC with that of close others, as compared to those of acquaintances and celebrities (β = 0.06, t(43) = 2.70, p = 0.007). A main effect of loneliness was found across all target conditions such that greater loneliness was associated less MPFC activation (β = -0.065, t (41) = -3.43, p < 0.001). Loneliness was also found to be negatively associated with rated self-other similarity across all target conditions (β = -0.05, t(41) = -3.67, p < 0.001). Finally, fMRI data showed that loneliness was associated with an altered neural map of social connections: as loneliness increased, the neural representation of close others became more similar to that of acquaintances in the MPFC (p < 0.001), and within the acquaintance group, individual acquaintances became more similarly represented to one another (p = 0.049).

Overall findings suggest that the MPFC neurally maps social connections as a function of others’ position within one’s social network, categorizing connections as within or outside of the network and representing closer social ties as being closer to the self. Loneliness was associated with an altered neural map of social connections, with blurred boundaries surrounding weaker ties (acquaintances) and the self being represented as more distant or dissimilar to others in general. Data suggest that the subjective experience of chronic loneliness may be reflected at the brain-level by a “lonelier neural self.” Findings from the current study provide unique insight into the ways in which the social brain uses interpersonal maps to help navigate social interactions, shedding light on the distinctive impact of loneliness at the neural level. Additional research is needed to further evaluate how social disconnection can restructure the brain’s representation of self and other, particularly in individuals with depression.

Source: Courtney AL, Meyer ML. Self-Other representation in the social brain reflects social connection. Journal of Neuroscience. 2020. DOI: 10.1523/JNEUROSCI.2826-19.2020.

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Posted July 14, 2020.

Angeline A. De Leon, MA, graduated from the University of Illinois at Urbana-Champaign in 2010, completing a bachelor’s degree in psychology, with a concentration in neuroscience. She received her master’s degree from The Ohio State University in 2013, where she studied clinical neuroscience within an integrative health program. Her specialized area of research involves the complementary use of neuroimaging and neuropsychology-based methodologies to examine how lifestyle factors, such as physical activity and meditation, can influence brain plasticity and enhance overall connectivity.

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