John-Dylan Haynes. Free will and the brain: Turning Libet upside down

Tuesday, 13 September, 2016 - 12:00 to 13:30

Room 52.015

Bernstein Center for Computational Neuroscience, Charité - Universitätsmedizin Berlin

When humans choose freely between different alternative actions, their choices are often predictable by prior brain signals. Using functional magnetic resonance imaging we found that classifiers can be used to predict the outcome of choices several seconds before a person believes to be making up their mind. This holds not only for simple movement choices, but also for complex cognitive actions. Using shifted classification analyses we found that early choice-predictive information can be dissociated from information related to the previous trial. Furthermore, during the early phase with choice-predictive information the default mode network was still active in the participants' brains. This potentially suggests that the prediction occured while they were not actively thinking about their upcoming choices. An interesting question is whether the onset of the choice-predictive brain signals constitutes a point of no return beyond which participants cannot avoid making a decision. We investigated this using real-time EEG classification of the readiness-potential. We found that people can override choice-predictive brain signals until a very late stage of processing. Taken together, our results suggest that choice-predictive brain signals are present, but that participants can control the outcome of a decision until a very late stage.

References
Schultze-Kraft M, Birman D, Rusconi M, Allefeld C, Görgen K, Dähne S, Blankertz B, Haynes JD. The point of no return in vetoing self-initiated movements. Proc Natl Acad Sci U S A. 2016 Jan 26;113(4):1080-5.

Soon CS, Allefeld C, Bogler C, Heinzle J, Haynes JD. Predictive brain signals best predict upcoming and not previous choices. Front Psychol. 2014 May 8;5:406.

Soon CS, He AH, Bode S, Haynes JD. Predicting free choices for abstract intentions. Proc Natl Acad Sci U S A. 2013 Apr 9;110(15):6217-22.

Haynes JD. Decoding and predicting intentions. Ann N Y Acad Sci. 2011 Apr;1224:9-21.

Bode S, He AH, Soon CS, Trampel R, Turner R, Haynes JD. Tracking the unconscious generation of free decisions using ultra-high field fMRI. PLoS One. 2011;6(6):e21612.

Soon CS, Brass M, Heinze HJ, Haynes JD. Unconscious determinants of free decisions in the human brain. Nat Neurosci. 2008 May;11(5):543-5.

Haynes JD, Sakai K, Rees G, Gilbert S, Frith C, Passingham RE. Reading hidden intentions in the human brain. Curr Biol. 2007 Feb 20;17(4):323-8.