’On your marks. Get set. Go!’ Mapping delayed responses in the brain

Neuroscientists at EPFL identify the brain mechanism that we use to prepare a timely action while suppressing premature execution. In some ways, we can think of the brain as an input/output machine; it receives signals from the environment and the body through peripheral and sends back appropriate responses. And although this is an oversimplified view of the world's most complex computer, it is nonetheless the basis of an enormous amount of behavioral research. For example, a group of researchers led by Professor Carl Petersen at EPFL's School of Life Sciences has published a paper in Neuron where they explore what neuroscientists refer to as a "delayed motor response". The importance of the study is self-evident: reacting to stimuli in a timely manner - not too early, not too late - can be critical, not only for biological, but also social survival. "Our behavior is dominated by internal appetites like 'want to eat' or 'want to touch', which come up in our mind as we explore the sensory world," says Vahid Esmaeili, one of the study's lead authors. "However, it is often critical to wait until appropriate moment before starting an action; for instance, in a sprint race, you get ready with the 'Get Set' signal, but must not move before the 'Go', regardless of how eager you are." The researchers explored the mechanism behind delayed motor responses by training mice to perform a behavioral task simulating this process: the mice would first receive a small vibration to their whisker, which acted as a "Get Set" signal.