title: Analysis of a choice-reaction task yields a new interpretation of Libet's experiments.
abstract: Benjamin Libet has demonstrated that the readiness potential precedes the time at which participants consciously decide to perform an intentional motor act, and suggested that free will is an illusion. We performed an experiment where participants observed a stimulus on a computer monitor and were instructed to press one of two buttons, depending on the presented stimulus. We found neural activity preceding the motor response, similar to Libet's experiments. However, this activity was already present prior to stimulus presentation, and thus before participants could decide which button to press. Therefore, we argue that this activity does not specifically determine behaviour. Instead, it may reflect a general expectation. This interpretation would not interfere with the notion of free will.
authors: Otto-von-Guericke-University, Department for Biological Psychology, Magdeburg, Germany. Christoph.Hermann@nat.uni-magdeburg.de
authors: Christoph S
authors: CS
authors: Herrmann
authors: Michael
authors: M
authors: Pauen
authors: Byoung-Kyong
authors: BK
authors: Min
authors: Niko A
authors: NA
authors: Busch
authors: Jochem W
authors: JW
authors: Rieger
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D002755:Choice Behavior / Q000502:physiology; D003265:Contingent Negative Variation / Q000502:physiology*; D003627:Data Interpretation, Statistical; D004585:Electrooculography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D014836:Volition