We all intuitively have a sense that we are the architects of our actions. If we raise our arm, then we can say that we willed it. This gives us the feeling that we have free will and that we do things by our own volition. However, there is evidence to suggest that we might not be in control as much as we would like to think. This comes in the form of a discovery by the neurosurgeon Wilfred Penfield and an experiment by the physiologist Benjamin Libet.

Penfield was a neurosurgeon who in the 1940s made a remarkable discovery. Patients undergoing Brain surgery are often partly conscious during the surgery. This is because the brain, itself, does not sense pain and because it is important to identify where a person’s speech areas are located before you go tinkering around in someone’s brain. What Penfield found was that if an area of the brain called the primary motor cortex was electrically stimulated during the course of a surgery, the patient would move a particular body part without having willed it. For instance, if the motor cortex that controls arm movement was stimulated, the patient would raise their arm and say that they didn’t mean to do that. This shows that the brain initiates our actions.

Libet conducted his now famous experiment in 1983. Participants watched a clock hand that made a complete revolution in 2.5 seconds. They were instructed to voluntarily flex their hand at a time of their choosing and to note the position of the clock hand when they did this. At the same time, their brain activity was being monitored by an electroencephalograph. A spike in our brain waves, called the Readiness Potential, occurs when we make motor movements. The experimenters thought that the readiness potential would occur at the same time that people flexed their hands, but what they found was that it actually preceded participant’s actions by 200 to 500 milliseconds (a fifth to a half second). This was an unexpected finding.

Libet’s experiment caused quite a stir. The results show that the brain decides to initiate our actions before we become aware of them. It brings into question whether we actually have free will in our actions. Further research showed that we have about a quarter second to inhibit our actions after a readiness potential. Libet calls this our “conscious veto.” So, even though we might not have free will, we have free won’t.

The discovery that brain processes initiate our actions without our awareness is hard for people to accept. It means that the brain is calling the shots and we follow along. We do, however, have the ability to veto our actions so we aren’t hopeless automatons. It would also be difficult for us to live in a way that we didn’t think we initiated our actions. Free will is perhaps the mind’s best trick. It’s an illusion that makes us feel like we are in control.