The 91-year-old said the brain responds to an external command before the person makes any conscious decision, suggesting that free will is a rationalization produced by the mind after the fact to explain its actions, the Los Angeles Times reported Monday.
He even wrote a book on the subject in 2004 called “Mind Time: The Temporal Factor in Consciousness."
Neurobiologist Dr. Robert W. Doty of the University of Rochester said of the book: "his is almost the only approach yet to yield any credible evidence of how conscious awareness is produced by the brain. Libet's work is unique and speaks to questions asked by all humankind."
Libet is survived by his wife Fay; two sons, Julian Mayer Libet and Dr. Ralph Arnold Libet; and two daughters, Moreen Lea Libet, and Gayla Bea Libet.