In her research, Visser put subjects under pressure by administering a small electric shock to their finger at unexpected moments. ‘That put participants in the experiment in a constant state of stress, similar to what you would feel if you were a goalkeeper playing a World Cup final.’ At the same time, subjects had to respond to suddenly appearing visual targets. The neuroscientist then looked at the strength of muscle reflexes and saw that they were increased under stress. 'We saw that muscle reflexes were greater when a person was under stress. The difference between a movement to the left or right was more obvious. So in stressful situations, the communication between brain and muscles is stronger.'
World Cup final
Visser suspects that this difference appears because it is more important to make and execute the right decision under stress, and you prepare your body accordingly. This used to be important when we had to choose between hiding or running away from wild animals, but now it still applies to World Cup finals.
Visser: ‘Many people think that when a ball comes at him or her, a goalkeeper first decides whether to jump to the left or to the right. We know from previous research that this is not how it works: there is a continuous exchange of information between your brain and your muscles. Your body is already preparing to go left before your brain makes that decision. My research now shows that a different mental state of a goalkeeper, for example due to stress, can affect that process.'
The result is not only useful for goalkeepers: ‘Of course, it is still futuristic stuff, but if we have more knowledge of how this process works in a properly functioning body and head, we can also start looking at how to improve this process in people with brain disorders who have difficulty with certain movements.’