快猫短视频

Where is your self?

FOR the Ancient Egyptians, it was the heart. For philosopher Ren茅 Descartes, it was somewhere entirely separate from the body. According to the Buddhist concept of anatta, it isn鈥檛 anywhere, because the thing concerned doesn鈥檛 exist.

But what does modern science say about where your self 鈥� your 鈥渟oul鈥�, if you like 鈥� resides?

At first pass, that might not seem a particularly scientific question. Regardless, most of us have an intuitive answer. When, in as-yet unpublished work, and her colleagues showed people from the US and India pictures of flies circling around a person, and asked which flies they thought were closest, the results were striking: regardless of cultural background, most people pointed to flies near a person鈥檚 eyes. 鈥淭his suggests there is a universal sense of the self being located in the head, near the eyes,鈥� says Starmans, a psychologist at the University of Toronto in Canada.

Subjectively at least, the eyes being windows to the soul checks out. 鈥淭he sense of where in our bodies we are located is informed by our dominant experience of the world,鈥� says Starmans. 鈥淎lmost all of our input from the world comes in through our head.鈥�

What our heads do with these inputs is certainly incredible, and key to our feeling that we are coherent beings. Our brains take a hotchpotch of electrical messages from our sense organs 鈥� eyes, ears, nose, skin 鈥� and combine them with memories to create a vivid, unified sense of conscious experience that is continuous in time.

How exactly this happens is still something of a mystery. But can we be any more specific about where it happens?

What鈥檚 clear 鈥� sorry, Descartes 鈥� is that, for most of us, our self is firmly anchored in our material bodies. In some extremely rare conditions, people have a sense of existing outside their bodies: those experiencing heautoscopy, for instance, see a doppelg盲nger, and feel they are located both in their own body and the doppelg盲nger鈥檚. 鈥淭hey are in two places at one time. It鈥檚 very disturbing,鈥� says , a cognitive neuroscientist at Anglia Ruskin University in the UK.

Similar illusions can be generated in the lab. For example, volunteers who have their back stroked while wearing a virtual reality headset showing a simulation of themselves being stroked start to feel that they are closer to their virtual self than to their actual body.

Brain scans show that a region called the temporoparietal junction is affected. 鈥淭his area is key for the brain computation that creates the perception of where your self is located in space,鈥� says Aspell.

A twist, however, is that this process is shaped not just by sensory information from the outside world, but by signals from within our body, too. A link between 鈥渋nteroception鈥� and our bodily self-consciousness was shown in 2016 by neuroscientist Hyeong-Dong Park at the Swiss Federal Institute of Technology in Lausanne and his colleagues. They measured the 鈥渉eartbeat-evoked potential鈥�, a signal that arises in the brain due to our heartbeat, while volunteers underwent a full-body illusion, and between the strength of the signal and the strength of the illusion. Other studies have since provided additional evidence.

So while modern science has long fixated on the brain as the seat of our conscious experience and our sense of self, it seems 鈥� Ancient Egyptians take a bow 鈥� that the heart and perhaps other parts of us may get a look-in too. 鈥淚t was like the mind was divorced from the body,鈥� says Aspell. 鈥淲e are realising how the mind is completely shaped by the body.鈥�

鈥淢any parts of our body may contribute to our sense of who we are鈥�