Discoveries

July 19, 2023

Anchoring the Self

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Scientists recently discovered that “a sausage-looking piece of the brain” is responsible for people experiencing out-of-body experiences, NPR reported.

Neurologist Josef Parvizi had come across an epilepsy patient whose seizures were causing him some very strange symptoms, such as feeling as if “floating in space.”

Initially, Parvizi and his team presumed that this was caused by seizures in the posteromedial cortex, an area toward the back of the brain. This region has a brain network involved in the narrative self, which helps individuals define themselves.

For their study, they conducted a series of experiments on the patient and eight other volunteers who also experienced severe epilepsy.

The researchers placed electrodes on the participants’ brains and waited for a seizure to occur. Because these electrodes could also deliver pulses of electricity, they also stimulated different areas of the brain to see whether they affected a person’s sense of self.

It turned out that it wasn’t the posteromedial cortex, but the anterior precuneus.

The team explained that this area – found between the brain’s two hemispheres – appears important to a person’s sense of inhabiting their own body, or bodily self.

Whenever this region was stimulated, the volunteers felt detached from their own thoughts and no longer anchored in their own bodies.

This is particularly surprising because the anterior precuneus is not connected to the brain’s system for maintaining a narrative self and is more focused on the sense that something is “happening to me,” not another person, Parvizi said.

Other researchers noted that the findings could help in developing forms of anesthesia that use electrical stimulation instead of drugs. It could also help explain the antidepressant effects of mind-altering drugs like ketamine.

This story originally appeared in the July 19, 2023 newsletter, Moving On.