by Kent Bottles, MD

First posted on Kent Bottles’ Private Views

Kent Bottles Host of Kent Bottles' Private Views
Kent Bottles, MD, Host of Kent Bottles’ Private Views

In many ways this long and meandering four-part blog post is entirely Michael S. Gazzaniga’s and Benjamin Libet’s fault. We have already met Gazzaniga and his left-brain interpreter theory that resulted from studying split-brain patients who underwent surgery to treat epilepsy. Gazzaniga has explored what these studies mean in several books, all of which are written in a way that the layperson can understand. David Wolman has recently published in Nature a nice overview article that would be a good place to start for someone just starting to grapple with their brain’s inherent need to explain things, even when the brain does not have a clue as to what is really going on (

As shocking as my brain’s need to confabulate to make sense of a world that increasingly makes no sense is the work of Benjamin Libet of UCSF who stimulated the brain of an awake patient undergoing surgery; he discovered a time lapse between stimulating the cortex that represents the hand and when the patient signaled they were conscious of sensation in the hand. In more recent studies, John-Dylan Haynes showed that the outcomes of an inclination can be encoded in brain activity up to 10 seconds before the patient is conscious of it. Chung Siong Soon also expanded Libet’s work when he showed that regions in the cortex associated with voluntary movement lit up on fMRI scans five seconds before the subject was aware of making a choice. Song concluded that a network of control areas in the brain “begins to prepare an upcoming decision long before it enters awareness.” This phenomenon has been labeled Bereitschaftspotential, which I cannot pronounce, or readiness potential, which is easier for me to say. Gazzaniga summarizes the staggering implications of these experiments:

“If actions are initiated unconsciously, before we are aware of any desire to perform them, then the casual role of consciousness in volition is out of the loop. Conscious volition, the idea that you are willing an action to happen is an illusion.” (Who’s In Charge? 2011)

Libet has written:

“If the ‘act now’ process is initiated unconsciously, then the conscious free will is not doing it.” (Journal of Consciousness Studies 8 (2001)

This idea that my brain makes decisions to act before I am conscious of them confuses me because I have a hard time accepting that my decisions are not mine own. I experience that I have free will. Patrick Haggard shared my dismay when he wrote that Libet’s original experiment in the 1980’s was “one of the most philosophically challenging…in modern scientific psychology.”

Raymond Tallis, who we met in Part III criticizing fMRI studies in his book Aping Mankind, has offered a different interpretation of these readiness potential studies:

“We need not only to look at the action Libet’s subjects were asked to perform but also to fill in some of the context in which they performed it. The action was the simplest imaginable: a flexing of the wrist…That movement was itself only a minute part of a long sequence of movements amounting to a large-scale action that could be described as ‘taking part in Dr. Libet’s experiment.’ This large-scale action began at least as far back as getting up in the morning to visit Libet’s lab…; involved consenting to take part in an experiment whose nature and purpose and safety was fully understood; and required…listening to and understanding and agreeing to the instructions that were received – and then deciding to flex the wrist. In other words, the immediate prior intention, the psychological event timed by Libet, was not the whole story of the action but only a tiny part of it.”

The philosopher Tim Crane has influenced Tallis’ interpretation by pointing out that “our actions are interconnected, as are intentions, decisions, and plans. The fact that the decisions in the Libet experiment seem to follow the actions is also irrelevant, Crane argues, because our actions unfold without there being explicit decisions…at every node. When I am walking to the pub to meet you, there isn’t a separate decision corresponding to every one of the hundred steps I take to get there.”

Gazzaniga has also helped me think through this problem. He writes that the hard determinists in neuroscience make the following causal chain claim:

“(1) The brain enables the mind and the brain is a physical entity; (2) The physical world is determined, so our brains must also be determined; (3) If our brains are determined, and if the brain is the necessary and sufficient organ that enables the mind, then we are left with the belief that the thoughts that arise from our mind are also determined; (4) Thus, free will is an illusion, and we must revise our concepts of what it means to be personally responsible for our actions.”

Claim two is the weak link in the above argument; the physical world may not be predictably determined because “the nonlinear mathematics of complex systems does not allow exact predictions of future states.”

The “aha” moment for me was when Gazzaniga, like Tallis, claims that looking for free will in individual brains makes no sense if these human capacities are emergent properties found in the “group interactions of many brains.” Nobel prize winner Robert Laughlin in A Different Universe describes the importance of the concept of emergence:

‘What we are seeing is a transformation of worldview in which the objective of understanding nature by breaking it down into ever smaller parts is supplanted by the objective of understanding how nature organizes itself.”

Gazzaniga wryly drives this point about different levels of organization, each of which require a different set of laws, when he comments that one cannot predict the freeway will be full of traffic during rush hour by examining a cam shaft of an automobile.

Tallis calls the level of organization where we have free will “the human world.” He describes “the human world” as “a new kind of space, an arena we humans have collectively created, which is the theatre of our freedom, to which our selves relate: the place in which we live our lives as persons rather than as organisms.”

I think we are finally getting somewhere, and I hope to be able to complete this blog in Part V, which will appear shortly.

Patricia Salber MD, MBA (@docweighsin)
Patricia Salber, MD, MBA is the Founder and Editor-in-Chief of The Doctor Weighs In. She is also the CEO of Health Tech Hatch, the sister site of TDWI that helps innovators tell their stories to the world. She is also a physician executive who has worked in all aspects of healthcare including practicing emergency physician, health plan executive, consultant to employers, CMS, and other organizations. She is a Board Certified Internist and Emergency Physician who loves to write about just about anything that has to do with healthcare.


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