Irrational beliefs would be the consequence of the blocking of a receptor regulating communication at the level of synapses, the contact zones between neurons. A phenomenon known to give rise to psychotic symptoms.
- Blocking a receptor regulating contact between neurons generates a tendency to believe in the improbable
- This blocking destabilizes decision-making by favoring information that confirms our opinions.
What if adhering to so-called “conspiracy” theories was a form of psychosis born of the blockage of a synaptic receptor? This is suggested by a study conducted by a study of neuroscientists and psychiatrists from Sainte-Anne Hospital and the Ecole Normale Supérieure published in the journal Nature Communications. This makes the link between the blocking of a receptor regulating contacts between neurons and a tendency to believe in the improbable. And blocking this NMDA receptor is known to give rise to psychotic symptoms.
Faced with an unpredictable and uncertain environment, some people become more inclined to believe in the improbable. It is this mechanism that makes conspiracy theories successful, which has been exacerbated in particular by the Covid-19 pandemic.
High uncertainty and premature decision making
To understand this phenomenon, the researchers asked a group of healthy volunteers to make decisions based on uncertain information. Some were given a very low dose of ketamine (a molecule that blocks the NMDA receptor), others a placebo product. By comparing the effects on brain function of the ketamine group to that of the placebo group, the scientists found that the administration of ketamine produced a high feeling of uncertainty but also premature decision-making. “A blockage of the NMDA receptor destabilizes decision-making by favoring information that confirms our opinions to the detriment of information that invalidates them”, underlines Valentin Wyart, research director at INSERM. And it is of course on this phenomenon that conspiracy theories thrive.
“These results suggest that the observed premature decision-making is not the consequence of overconfidence, but rather the result of high uncertainty that causes the emergence of improbable ideas that no outside information can invalidate” , he says. And he points out that this type of reaction to uncertainty is often observed during the early stages of psychosis when a feeling of strangeness precedes the emergence of delusional beliefs.
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