Brains warp time to gain information

Movies sometimes show an accident about to happen in slow motion so that the audience sees it mirrored on the actor's face as he or she prepares to try and avoid it. According to recent research by EU-funded scientists, it turns out that our brains in fact slow down or dilate time while preparing to act. The project 'Perception of time during action preparation' (ACTION AND TIME) demonstrated that visual sensory perception is modulated by preparation for a movement related to that input.

Subjects were shown a visual stimulus, a white disk, on a computer monitor. They were asked to judge its duration as either short or long. Control subjects were not asked to do anything. In the experimental condition, the subjects were instructed to reach out toward a second disk that appeared on the monitor right after the white disk disappeared.

Results showed that the visual stimulus was perceived to have a longer duration only when an action was prepared. In addition, the amount of time dilation was related to the degree of motor preparation, manipulated by the uncertainty that an action would be required. Interestingly, preparation for action not only dilated time perception but also slowed down the perceived frequency of a flickering stimulus. Experiments also showed that this slowing down was linked to an increased capacity for visual information processing.

As the first scientific study to support reports by baseball players that the ball seems to slow before they swing the bat to hit it, it received widespread media attention. The findings were broadcast by the British Broadcasting Corporation (BBC news), Le Figaro, the Austrian Broadcasting Company and CBS News in the United States.

In addition to its inherent value in deeper understanding of nervous system function, the project's outcomes are relevant to many fields in which action to a stimulus is required. These include athletics, gaming, and just about every type of job involving manual labour or vehicle operation. Better understanding related mechanisms can eventually help manufacturers to create better products, players to hone their senses and employee training programmes to have the most impact.