How your brain keeps time: Consistent probability calculations help you react rapidly - medicalxpress

The brain continuously calculates how likely it is that something will happen within the next three seconds. It uses this assessment to prepare quick and accurate responses. Credit: Max Planck Society

Humans respond to environments that change at many different speeds. A video game player, for example, reacts to on-screen events unfolding within hundreds of milliseconds or over several seconds. A boxer anticipates an opponent's moves—even when their timing differs from that of previous opponents. In each case, the brain predicts when events occur, prepares for what comes next and flexibly adapts to the demands of the situation.

A study by neuroscientists from the Ernst Strüngmann Institute of the Max Planck Society, Goethe University Frankfurt, the Max Planck Institute for Empirical Aesthetics, and New York University, explains how the human brain predicts the timing of future events.

The research, published in the journal Proceedings of the National Academy of Sciences, shows that the brain continuously estimates how likely something is to happen within the next three seconds—and uses this estimate to prepare fast and accurate reactions.

How the brain predicts timing

Using psychophysical experiments, the researchers measured how quickly people responded to simple visual and acoustic signals, such as flashes or tones, while carefully controlling when these signals were likely to occur. From these experiments, they identified two key principles that the brain uses to predict the timing:

The brain uses the same basic probability calculation regardless of whether an event is expected in a few hundred milliseconds or in several seconds. This means the brain predicts the future in a consistent, scale-free way across different time ranges—up to at least three seconds.

At the same time, probability sharpens the sense of time: When an event is likely to happen at a certain point in time, the brain tracks time precisely. When an event is less likely, timing becomes less precise. This finding challenges a classic explanatory approach in psychology and neuroscience known as Weber's law, which suggests that timing precision should not depend on probability.

Implications for behavior and adaptation

"The brain predicts the timing of future events in different situations and at different speeds in the same way. This helps explain why people can adapt so easily to new environments," says Matthias Grabenhorst, first author of the study.

These insights can help us better understand many aspects of human behavior, including attention, decision-making, and even disorders that impair timing and prediction. The study sheds light on how the brain continuously prepares for the near future—second by second. 

Provided by Max Planck Society 

by Max Planck Society

edited by Sadie Harley, reviewed by Robert Egan 

Source: How your brain keeps time: Consistent probability calculations help you react rapidly