Monkey recognizing itself in a mirror.
Have you ever wondered about the origin of your sense of self?
It is most commonly thought that our identity is bound to our bodies, yet our bodies are not necessarily who we are.
Imagine someone loses a finger in an accident. They lost a part of their body, but not necessarily a piece of their identity. The same applies for increasingly drastic scenarios, like losing a leg or having your heart replaced in a transplant. Although most people could not name the specific place in our bodies that carries the core of our identities, we generally agree that it hides within our brains, in what we describe as consciousness but cannot yet fully define.
Consciousness is perhaps the most intriguing feature of our existence and we, humans, have not yet completely understood where it comes from or how exactly it works.
But we may be getting a little closer. A new study, published in the journal Social Cognitive and Affective Neuroscience, reveals how a specific brain region might be responsible for preserving our sense of self.
Ventromedial prefrontal cortex shown on ventral and medial views of the brain.
The medial prefrontal cortex (mPFC) is a brain region related to self-thought. It is divided into dorsal (upper), and ventral (lower) regions. In their study, Debora Stendardi, a PhD student at the University of Bologna, and co-authors found that the ventral medial prefrontal cortex (vmPFC) is the region in the brain that puts together ideas of the present and future self, helping to form and maintain a consistent identity. Damage to that area could lead to an impaired sense of identity.
In her research, Stendardi compared three groups of people: (1) those with lesions to the vmPFC area, (2) a control group with other types of brain injuries, and (3) a second control group of individuals with no brain injuries.
By comparing these groups, they could infer the impact of lesions to the vmPFC on the self-reference effect (SRE). The SRE is a common scientific way of investigating how our sense of self connects to the brain. It refers to the favoring of memories related to the self, which are typically more prominent in our thoughts than, for instance, memories concerning more general knowledge such as the characteristics of the seasons, or other events and experiences in which we are not directly involved.
In the study participants were asked to list adjectives about themselves, in the present and ten years in the future, and then do the same with celebrities.
The researchers observed that, normally, people are better at recalling information related to themselves not only in the present (as other SRE studies have shown) but also in the imagined future. And although people with brain injuries were generally somewhat less able to recall imagined details about their future self than healthy individuals, this effect was still present. However, the participants with lesions to the vmPFC had little or no ability to recall those self-related memories. They also had trouble remembering references for celebrities in the present and future and had less self-confidence in seeing their own personality traits. These findings indicate that the vmPFC has a central role in forming and maintaining our sense of identity.
Dimensions and sub-dimensions of the self.
Studies of brain-damaged areas provide a window to assess the roles of specific brain regions in different functions.
Lesions to the vmPFC are related to altered personality, blunted emotions, and other impairments of emotional and executive functions such as misfunctioning memory retrieval, that lead to more difficulty in discerning between false and true memories.
Suzanne Kamphausen, from the Department of Computational Neuroscience at the Max-Planck Institute for Biological Cybernetics, and colleagues published a paper showing the ventral and dorsal mPFC, along with the amygdala, are essential parts of the neural mechanism underlying borderline personality disorder (BPD).
The core features of this condition are emotional dysregulation and identity disturbance, contributing to an impaired sense of self. People with this condition have difficulty describing features of themselves and others, and struggle to assemble beliefs, interests, and life goals stable enough over time to develop a sense of self.
Dr. Natalie Gold, a principal advisor in Public Health England Behavioral Insights (PHEBI), at the UK Health Security Agency, describes that this can lead to “extreme and polarized self‐conceptions, feelings of puzzlement about changes in the self, lack of a coherent image of self, explosive shifts into states where the perception of self is distorted and shows weak correspondence with external reality, (…) and no clear concept of self‐development.”
Our conscious mind is always in the present, as life only happens here and now.
Yet we need past, present and future references to construct our sense of self. We imagine the future based on available knowledge and visit the past through our memories – which are also a form of imagination. The ability to imagine the future is essential in human evolution and may have contributed to our history of forming social groups and even the development of language. As we travel through time and experience new things, we continuously update the collection of mental images of who we are. The vmPFC is central in connecting and maintaining all of this tied to an identity.
Also worth noticing, Stendardi’s study may have provided the first picture of a particular human trait that research on social psychology has long anticipated.
In the 1970s, Henri Tajfel first proposed the Social Identity Theory, addressing our tendency to incorporate the characteristics of groups in which we participate into our sense of self, or our identity, which are connected to our perceptions about group members and nonmembers. Scholars have extensively used this theory to assess both in-group favoritism and out-group discrimination. Now it is even more clear that our conceptions of self and others are inherently intertwined, as the same brain structures are responsible for constructing who we are and who other people are in our minds. Stendardi and colleagues have taken a picture of what Tajfel could only theorize just five decades ago.
Interestingly, previous studies had already shown that this brain region activates similarly when individuals think of their past selves or about somebody else – a fundamental connection in our relative capacity to perceive ourselves and others.
Scientists believe this might have to do with our judgments about our past selves. Since we naturally seek a more positive self-image in the present, we tend to distance ourselves from who we once were (or who we perceive ourselves to have been in the past). It is fascinating to think that we have evolved to naturally distance ourselves from who we once were, yet often seek positive views about ourselves in the present and future. It seems that, in our brains and minds, we continuously leave who we were to become who we are.
