Neuroscience Blog

Written by Brett Weiss

February 2019

Perceptions in conscious awareness (qualia as they are often called) are very real to each person. At the same time, they are in fact “creations of the mind.” Illusions demonstrate time and again that the mind can be easily fooled. Furthermore, neurologists see that ‘false perceptions’ regularly occur as personal realities.

One possible “creation of the mind” that may constitute an illusion is the perception of free will. Heisenburg physics (as opposed to Newtonian physics) allows that the future is not deterministic and that future events can only be probabilistically determined given that some events are stochastic (random). Some philosophical schools of thought use Heisenburg physics to support their view that free will does exist. What does science say about the physiology of free will?

Libet et al. performed an experiment that utilized EEG to measure perception of willing to move (W) and an EEG activity in the brain that gives rise to movement called Bereitschaftspotential (BP), also called Readiness Potential (RP) in English. The will to move (W) and Readiness Potential (RP) were compared to actual movement (M). Subjects sat before a clock face with a ball that moved around the clock in 3 seconds to report when they perceived the will to move (W). Actual movement (M) was compared with will to move (W) and the Readiness Potential (RP). The Readiness Potential starts about 1 to 1.5 seconds before movement. Strikingly, the will to move starts about 300 ms prior to movement. The RP was 700 ms prior to W. Thus, a possible conclusion of the results is that brain activity for movement precedes a perceived will to move.

Libet et al. said that initialization of movement occurs unconsciously. At the same time, they thought that free will was actually still possible because movements that arise unconsciously can be consciously vetoed. One might say that Libet et al. thought instead of having a free will, people have a ‘free won’t (Hallet, 2016).’

Other studies have reproduced these results many times. The data are clear; however, interpretation is not easy. Does interplay of subconscious impulses dictate behavior? What neural mechanism would explain a “free won’t” process?

References

Hallet M (2016). “Physiology of Free Will.” Ann Neurol. 80(1): 5-12.