Who Makes the Decision?

Did you know that taking some physical action—reaching for a glass of water, for example—appears to begin in one part of your subconscious brain even before your brain consciously ‘wills’ to do   the action and initiates it? Researchers such as Hans Helmut Kornhuber and Luder Deecke, as well as Benjamin Libet in the 1980s have studied this phenomenon using simple finger movement. Kornhuber and Deecke found a precursor spike in the brain 0.8 seconds before the finger actually moved and dubbed it the ‘readiness potential.’ They also found a second and smaller spark of electrical activity at 0.05 seconds before actual finger movement. Libet used a clock to identify the moment of ‘wanting to move a finger.’ That moment occurred after the point of readiness potential but before sensors detected any actual finger movement. Conclusions were that part of your brain ‘wills’ an action to occur before your conscious brain makes you aware of your desire to make it happen. Hmmm.