Libet’s readiness potential experiments are old hat. In them, Libet measured a spike of characteristic neuronal activity up to 300ms before the decision to push a button. Even though Libet himself thought that free will acts as a veto faculty sometime after the rediness potential his data were (and are still at times) heralded by biological determinists and materialist polemicists as a denunciation of free will.
Regardless of the controversy surrounding Libet’s contribution to the free will debate, his experiment’s notoriety alone begs additional investigation. Nature Neuroscience published an interesting article by a group at the Max Planck Institute for Human Cognitive and Brain Sciences in Germany that elaborates on his studies using fMRI.
There has been a long controversy as to whether subjectively ‘free’ decisions are determined by brain activity ahead of time. We found that the outcome of a decision can be encoded in brain activity of prefrontal and parietal cortex up to 10 s before it enters awareness. This delay presumably reflects the operation of a network of high-level control areas that begin to prepare an upcoming decision long before it enters awareness.
Siong Soon et al’s findings contrast Libet’s in that they pinpoint a different and higher level control area that dictates the occurrence of the readiness potential.
These findings are a good indicator of the existence of unconscious processes that influence decision making; however, they are not a significant addition to the materialist’s bag of tricks. They do not denounce free will. They simply suggest that, as we would’ve anticipated, decision making processes have something to do with cortical neuronal activity.
Libet passed away in late 2007.