The US neurophysiologist Paul Nunez previously wrote “Electric Fields of the Brain” (1981) and “Neocortical Dynamics and Human EEG Rhythms” (1995), and in fact his credentials in the field of brain studies harken back to a paper originally written in 1972 and ambitiously titled “The Brain Wave Equation” (an equation that eventually he resurrects in this book, 40 years later). In this book Nunez summarizes his novel ideas on the way that “brains cause minds” (to use Searle’s expression).
In the 1960s the US neurophysiologist Benjamin Libet discovered that the "readiness potential" precedes movement by about half a second, and awareness of this "decision to act" follows by about 300 milliseconds. In other words, the brain decides unconsciously to act, before we are aware of having decided to act. We become aware of the action only if the neural event lasts about 500 milliseconds.
A way to interpret this is that we are conscious only of electric field patterns in the brain that last about half a second. The scary notion, of course, is that a) we are not conscious of many "decisions" that our brain makes (anything that occurs in less than half a second) and we are conscious of "our" decisions only "after" the brain has already decided them. This can be interpreted as proof that free will is an illusion, or that free will has about 200 milliseconds to "veto" what the brain wants to do.
Nunez interprets Libet's experiments as showing that a) it takes about half a second to become aware of something because that awareness is due to some global brain activity with a lot of loops; and b) the conscious and the unconscious are in continuous communication, a feedback loop of its own.To read more, click here.