Now, researchers may have developed a greater understanding of how the brain produces the disorienting, disruptive feeling of being outside one’s body.
The mind and body function seamlessly as a single entity much of the time. However, a person may often experience a disconcerting feeling of “disassociation,” during which they feel as if they are looking inside somewhere outside their body.
Nearly 3 out of 4 people who undergo trauma report this phenomenon happening either during or any time after, according to Dr. Karl Deisseroth, who is a professor of bioengineering, psychology, and behavioral sciences at Stanford University in California.
Also, at some stage in their lives, about 2-10% of the general population experience it, he adds.
Dr. Deisseroth and colleagues recently conducted a study that allowed them, for the first time, to describe the brain function that initiates disassociation.
They have now reported their findings in the journal Nature.
With nerve cells in the posteromedial cortex of the brain firing synchronously at a particular pace, the sensation of disassociation starts.
Disassociation, and it can become persistent, may be both alarming and destructive. “We need to know more in order to improve therapies and to understand biology,” says Dr. Deisseroth.
Now, he says, “This research has identified brain circuits that play a role in a subjective experience that is well defined.”
“Beyond its potential medical implications, it gets at the question, ‘ What is the self? ‘In law and literature, that’s a major one, and significant even for our own introspection.’
The analysis also explains the molecular basis underlying the disassociation-causing process.
The brain’s role
“Dr. Deisseroth metaphorically defines disassociation” as the feeling of being outside looking at the cockpit of the plane that is your body or mind, and what you see is just not considered to be yourself.
In reality, the research is, in part, based on observations from a person who described the experience as “outside the chair of the pilot, looking at the gauges, but not controlling them.”
The study authors worked as part of the Stanford Comprehensive Epilepsy Program with this individual. During pre-seizure “auras,” which refers to the time span immediately preceding seizures, he experienced disassociation.
In an attempt to identify the brain activity causing his seizures, the researchers reported electrical signals from the cerebral cortex of the man. They found a specific electrical activity pattern that coincided with the aura. This was in the posteromedial cortex.
The researchers found that nerve signals firing synchronously produce a clear rhythm. At 3 Hertz ( Hz), or three times a second, the signal pulsed.
They subsequently discovered that if they electrically stimulated this region of the brain purposefully, the person experienced a disassociated aura but no subsequent seizure.
Confirmation in mice
Previous research has suggested that, as shown by changes in their behavior, mice experience disassociation.
For example, if a mouse on an uncomfortably warm surface simply raises its foot without licking it to soothe it, it is likely to experience disassociation, as would be expected. Scientists can induce this state using the drug ketamine.
In the latest analysis, by using light to optogenetically stimulate neurons in the rodent equivalent of the human posteromedial cortex, the researchers attempted to induce disassociation in mice.
They saw disassociative behavior without the presence of ketamine when they administered stimulation at the same 3-Hz intensity they saw in the human brain.
Further research led to the discovery that for the generation of the 3-Hz pulse, a particular protein type called an ion channel is required.
Recognizing the function of these proteins may lead to the development of new therapies, such as epilepsy, borderline personality disorder, and PTSD, that address disassociation more effectively and the conditions with which it is often associated.
