Australian researchers have uncovered what happens in the brain when people encounter predictable situations versus surprises, according to a June 22 report. The study provides insights into how the brain manages sensory information and updates memory.
The research found that during surprising events, the brain directs energy toward taking in more sensory information from the environment. This mechanism explains why unexpected events are remembered more vividly and accurately, as the brain updates its internal memory following such occurrences.
In contrast, when faced with familiar or expected situations, the brain begins to respond before they even happen. This allows for faster reactions but results in less detailed encoding of those experiences. "Our study is a fascinating insight into how the brain uses predictions to help us better perceive and interact with the world," said Dr. Reuben Rideaux from the School of Psychology at the University of Sydney. He added, "When the brain is faced with a predictable situation, it goes 'I already know what this is, I don't need to spend energy processing it carefully.'"
Dr. Rideaux compared this process to professional sports: "Imagine a professional tennis player who knows where her opponent's next serve is going to land. Their experience makes them move towards that spot before the ball is even struck and to get her racket in position to hit it back cleanly. Her brain had already prepared a motor response for the likely location and didn't bother encoding the precise location of the ball that confirmed what it already predicted." He continued, "That prediction buys her precious milliseconds, but if you ask her to recall frame by frame, exactly where the ball bounced inside the service box, her memory will be fuzzy. But it's the rare surprise serve down the middle, which she'll remember with vivid spatial precision."
The findings were published in The Journal of Neuroscience and address questions about 'adaptive efficiency,' referring to how neural energy is allocated under environmental pressures. To conduct their research, 40 participants viewed visual flashes around a circle while their brain activity was measured using EEG technology and pupil responses were tracked.
Participants responded more quickly and accurately to expected events but recalled exact locations less precisely than after unexpected flashes. The team also discovered that familiar events trigger two stages of reaction: initial prediction followed by reduced processing if expectations are met.
For future studies, Dr. Rideaux's team plans to explore how these mechanisms develop over time and investigate potential applications for artificial intelligence systems.
