Spontaneous EEG fluctuations determine the readiness potential: is preconscious brain activation a preparation process to move?
It has been repeatedly shown that specific brain activity related to planning movement develops before the conscious intention to act. This empirical finding strongly challenges the notion of free will. Here, we demonstrate that in the Libet experiment, spontaneous fluctuations of the slow electro-cortical potentials (SCPs) account for a significant fraction of the readiness potential (RP). The individual potential shifts preceding self-initiated movements were classified as showing a negative or positive shift. The negative and positive potential shifts were analyzed in a self-initiated movement condition and in a no-movement condition. Comparing the potential shifts between both conditions, we observed no differences in the early part of the potential. This reveals that the apparently negative RP emerges through an unequal ratio of negative and positive potential shifts. These results suggest that ongoing negative shifts of the SCPs facilitate self-initiated movement but are not related to processes underlying preparation or decision to act.
KeywordsFree will Intention to move Libet experiment Slow cortical potential Readiness potential
- Bennett MR, Hacker PMS (2003) Philosophical foundations of neuroscience. Wiley-Blackwell, Oxford Google Scholar
- Kotchoubey B (2012) Why are you free? Neurobiology and psychology of voluntary action. Nova Sci Pub, New YorkGoogle Scholar
- Schlegel A, Alexander P, Sinnott-Armstrong W, Roskies A, Tse PT, Wheatley T (2013) Braking up the wrong free: readiness potentials reflect processes independent of conscious will. Exp Brain Res 229(3):329–335Google Scholar