Every time you reach for something, there’s a squabbling match in your brain

Even the simplest of actions can arise from hidden competition. Imagine reaching for a cup. There are many ways of doing this, depending on where the cup is, whether you’re right- or left-handed, whether the handle is turned towards you, and so on. Your brain works through all of these possibilities at the same time, and they compete against one another until one wins out. Only after this neural battle does your arm start to move. A new study suggests that these competitive processes affect even simple decisions, like which hand we use to pick up an object. Even though this is one of the most common decisions we ever make, it has rarely been studied. To remedy that, Flavio Oliveira from the University of California, Berkeley filmed the movements of volunteers as they reached for targets that had been projected onto a table in front of them. In some ...