Each of us undergoes profound changes over the course of our lives, yet we still feel like the same person. Your ability to experience a stable, coherent sense of self is truly remarkable.
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Throughout life, we all experience deep transformations: growing from childhood into adulthood, learning new things, forgetting others, forming new relationships, and losing old ones. All of this is interwoven with the long nightly interruptions of sleep and dreams.
And yet, despite everything, we still feel like the same person. Ultimately, this depends on an ongoing construction process in the brain, which is far more flexible and fragile than you might imagine. Classic research in the late twentieth century studied people whose brains had been surgically split as a radical treatment for epilepsy.
This produced some strange consequences. Patients would sometimes perform contradictory actions, such as one hand buttoning a shirt while the other hand unbuttoned it. Yet even then, they maintained a coherent sense of self. They even invented explanations for their unusual behavior. Their brains were literally creating instant narratives to preserve a unified sense of identity. In healthy individuals, psychological research has revealed memory features that help strengthen this constructed sense of self.
For example, we are more likely to recall and rehearse memories that align with how we see ourselves. Imagine you consider yourself an introvert. You will probably find it easier to access and describe memories that support this view of who you are.
In this way, you are constantly editing your autobiography to match your current self-concept. A key part of this construction is the medial prefrontal cortex, located at the very front of your brain, just behind your forehead. Studies show that when people are asked which traits best describe them, now or in the future, this brain region becomes highly active, much more so than when making similar judgments about others.
Our constructed sense of self also extends to the things we own. When people are placed in brain scanners and shown various objects, the medial prefrontal cortex lights up when they see their own belongings. But it does not respond the same way to random objects that do not belong to them. This reveals how quickly and flexibly the brain redraws the boundaries of the self.
Memory processes are also crucial to this ongoing construction. Damage to the hippocampus, located deep within the brain near the temples, can prevent people from imagining themselves in the past or the future. This shows how dependent our continuous sense of identity is on active brain processes.
Your brain does not just construct your sense of self across time, it also maintains it in space, giving you a stable sense of ownership over your body. Another brain region, called the temporo-parietal junction, located behind your ear, plays a critical role in this aspect of identity.
A 2005 study found that when this region was electrically stimulated during brain surgery, patients experienced out-of-body sensations. They felt as if they were floating outside themselves. Our stable sense of self usually feels completely real and trustworthy. Yet it can be disrupted by brain damage and clever neurological experiments.
Taken together, the evidence suggests that your sense of “self” is a construction, one that your brain works tirelessly to maintain.
Source: sciencefocus.com
