At the core of your identity, a core of self-awareness combines memories of the past with the fleeting sensations of the present, adding a touch of anticipation for the future.
The question of whether this ongoing sense of ‘you’ is as robust as it feels has intrigued philosophers and psychologists through the ages. A new, small psychobiological study is weighing in and looking at brain scans to conclude that at least part of you is indeed consistent as you grow and age.
“In our study, we tried to answer the question of whether we are the same person all our lives,” said Miguel Rubianes, a neuroscientist from the Complutense University of Madrid.
“In combination with the previous literature, our results indicate that there is one component that remains stable, while another is more sensitive to change over time.”
Self-continuity is the basis of identity. Each time you use the word ‘I’ you are referring to a thread that brings together a series of experiences into a tapestry of your life, representing a relationship between the self of your childhood and one that has yet to emerge.
But identity is more than the sum of its parts. Consider the allegory of Theseus’ ship, or the grandfather’s ax paradox – a tool that has had both the shaft and head replaced, but is somehow still the same ax that belonged to grandfather.
If our experiences change us and exchange parts of our identity with every cardiac arrest and promotion, illness and windfall, can we really still say that we see ourselves today as the same person we were when we were four years old?
You could be forgiven for thinking this sounds more like philosophical navel gazing than something science can tackle. But there are perspectives that psychology – and even the wiring of our neurological programming – can work out.
Rubianes and his team mainly focused on neurology’s “ how and when ” to treat familiar faces, relying on previous research suggesting that visual self-recognition can act as an indicator to link to a person’s self-impression.
In what is known as the self-reference effect, we can better remember or recognize information if it is personally connected to us in some way, such as seeing our own face in a photo.
While there is plenty of evidence to support the phenomenon’s existence, the exact timing and mechanisms of the process in our brains remain an open question.
Conflicting studies have revealed different neurological processes to distinguish our own face from others, for example each with different brain regions used to recognize a set of known characteristics and assign meaning.
Determining the types of neurological activity involved can tell us whether we are simply triggered by a recognition of our own face, such as meeting an old friend, or making an actual connection with the self it represents, both in the past as in the present.
To work this out, the team performed a recognition task with a group of 20 students. Each was shown 27 images, including part of their own face, the face of a close friend and an unfamiliar face, all at different stages of life.
Each image flashed on a screen for one second at a time, requiring the participant to press a button to identify who he was seeing: himself, friend, or stranger. A second trial asked them to identify the person’s stage of life: childhood, adolescence, or adulthood.
Meanwhile, dozens of electrodes were examining the mix of brain waves buzzing out of their gray matter and painting a map of activity.
That map, and the timing of the participants’ responses, strongly suggest that our impression of the self – that sense of ‘I’ – is updated throughout our lives, giving it stability. We really process that open-teeth portrait of us in the fourth grade as ourselves, and not just as a familiar image of a child who happens to share our memories.
The study also revealed interesting similarities in the way we process impressions from our former self and that of our good friend, suggesting a complexity in how time can shape impressions of our identity.
It is of course important to note that this study was conducted with a small sample size and is far from the last word on the topic.
But the discovery that there is a rigid neurological basis for our sense of self that is modified by time and experience neatly mirrors other studies that suggest that there are also cultural influences on how we perceive identity.
Significantly, neurological descriptions of the specific brain bits responsible for sorting themselves out from a stranger can help us better understand why some people don’t share this impression.
Disturbances in that thread of recognition often define conditions such as schizophrenia, putting individuals at increased risk of self-harm.
“This demonstrates the importance of both basic and clinical research in the study of the role of personal identity as it promises to become a much more important concept than previously thought and can play a fundamental role in psychological evaluation and intervention processes,” says Rubianes.
Some days we all feel insecure about who we are. Rest assured, chances are you will always be there deep in your brain.
This research is published in Psychophysiology.