Faulty perceptions of time in the brain may cause delusions, Yale researchers have found.
Yale researchers believe they can predict delusions in individuals based on a low-level mechanism in the brain. Their findings were published in the Proceedings of the National Academy of Sciences on Sept. 18.
Delusions include everything from perceived psychic abilities to a conviction that the universe is “out to get you,” according to Michael Bronstein GRD ’21, co-author of the paper.
“We’ve identified a very low-level mechanism that may contribute to the very high-level beliefs of sufferers of illnesses such as schizophrenia,” first author Adam Bear GRD ’19 said. “And that’s not something that’s really been seen in the literature before.”
It takes mere milliseconds for the brain to fully register a stimulus from the outside world. That time lag is small, but, when it comes to rapid-fire events, those milliseconds can confuse our perception of time. For example, if individuals predict an event after it occurs, but before it is fully registered, they may believe they are capable of seeing the future.
“We anticipate things that have already happened, which is sort of this global delusion we all have, in a sense,” Bear said. “The idea that time can be messed up in your own experience is kind of scary and can undermine our feelings of agency and control.”
The researchers found that individuals suffering from delusions were more likely to report having correctly predicted random events. Bear and his team used a widely recognized scale called the Peters et al. Delusion Inventory to assess how delusional individuals are based on their own self-reported beliefs, Bronstein said. They found that individuals who scored high on this index were more likely to believe they had correctly predicted an event, even though that event had already occurred, said Tyrone Cannon, a co-author of the paper and a psychology professor.
In the experiment, subjects were shown five white squares and asked to predict which one was about to turn red. After the fact, they were asked to tell the researchers if their prediction had been correct, Bronstein said. When the window for prediction was relatively long, subjects reported approximately one in five correct guesses, reflecting the random design of the experiment. When that time frame was shortened, however, the self-reported accuracy of the predictions began to rise. The shorter time frame allowed subjects to see and subconsciously be influenced by the real result before making a prediction.
“Because of this delay in conscious awareness, your brain ‘anticipates’ events that have already been subconsciously processed and tries to fill in the blanks by telling a story of what’s going on,” Bear said.
According to the paper, self-reported accuracy was highest, and applied over the longest time frame, in those who scored high on the scale. Rather than believing that the square had already turned red by the time the prediction was made, some individuals may choose to believe they are simply clairvoyant and capable of sensing where the red square is going to appear.
The researchers’ work has the potential to explain real-life phenomena, like the ubiquity of individuals who claim to be psychic. People who truly believe themselves to be psychic may in fact be responding to the facial expressions of those whom they are reading, Bear said. Due to the time lag between stimulus and perception, they may confuse the timing of the response and their own prediction, further cementing their own belief that they can read minds, he added.
Thus far, the researchers have not focused their study on specific mental illnesses such as a schizophrenia. However, Bear believes that a more in-depth study into the way the time lag mechanism differs in schizophrenic individuals could illuminate some roots of the illness.
According to the National Institute of Mental Health, approximately 1.1 percent of the United States’ population suffers from schizophrenia.
Maya Chandra | firstname.lastname@example.org