Is anyone here familiar with the work of Benjamin Libbet

I've read of his work in other books and articles. I have a Scientific American issue devoted completely to the subject of Time, which I've been reading on and off, and his work was mentioned in one of the articles I was reading on the weekend. I also remember some of his experiments being mentioned in the book, Theatre of the Mind, by Jay Ingram. The experiment he's most famous for (where subjects had to note when they first made a conscious decision to flex their wrist) seemed flawed to me, but I did find the one where he stimulated the brain directly during surgery, and patients seemed to "back-time" a sensation felt elsewhere in their bodies fascinating. What are your thoughts?

“So, I guess the big problem for a materialist explanation, apart from accounting for all the non-material things, is how you account for our ability to be originators of our actions.” Well, I don’t think non-material things are always so difficult to account for. Consider television. The programs we watch on T.V. are non-material and bear no resemblance to the physical structure that brings them into existence. We can analyze the structure step by step, and see how a program manifests on the screen without having to postulate that a non-material power is at work. A non-man-made and simpler example is a rainbow: it’s a non-material phenomenon that arises when matter happens to be temporarily arranged in a particular way via natural, physical processes. As for accounting for our originating our actions, is this any different than accounting for why a plant grows toward the sunlight? We don’t know why organisms form and make efforts to survive and reproduce. They just seem to do it automatically under the right environmental conditions. Although consciousness is extremely complicated, and certainly amazing to experience subjectively, I still see it as just another mechanism for survival, along with many unconscious ones in humans, and other living things. “If there is only matter and all matter is deterministic then nothing we feel, think, say or do are we responsible for since we could have done no differently?” I think it’s possible that we may not truly have free will. We might as well operate as though we do, however, since knowing EXACTLY how an individual would act in various circumstances would require an extraordinary amount of computational power, not to mention a much more detailed understanding of the brain than we have now. We’d also have to take into the account the many, many random external experiences that affect an individual’s development, level of knowledge, emotional states on a given day, etc. The number of variables is overwhelming. “Why would we have evolved consciousness at all? What evolutionary advantage is there in certain creatures evolving consciousness when it seems we could do just as well without it?” I would think that an animal that is able to replay and analyze past experiences and imagine hypothetical ones would have better survival chances than a similar one without such an ability. I’m pretty sure it would have been impossible for humans to develop agriculture without consciousness. Birds with the capacity to figure out how to smash open shellfish by dropping them onto rocks would have better survival rates than similar birds searching for food mindlessly. “Well Eccles work as I understand it suggests that neural activity my proceed stimulation from sensory input, indicating some non-physical causal origin.” I’d like to find out more about these experiments. I’ve been looking around, but haven’t found any sites that don’t require a paid membership in order to view them. Can you describe the experiment you’re remembering in more detail? Is the Libbet experiment you’re thinking of the one where he stimulated the brain directly (during surgery on subjects who were awake), and asked them to report when they felt a sensation in a corresponding body part? Or is it the one where he had subjects watch a timer and note when they intended to make a movement? If it’s the latter, I think the results could have been confounded by the fact that the subjects had to perform a separate conscious action in timing their intentions. The timing was also a presumably a novel task for the subjects, which could have caused the lag; humans are much faster at performing actions they’ve done over and over again, than unfamiliar ones. Then there’s the time delay that surely must occur between having a thought, and noting that you have had one. Even if the experiment yielded indisputable results and brain regions related to movement do become active before we make the conscious decision to move, I don’t think this means that something extra is at work in our heads. Movement is largely an unconscious process. If, for example, you move your cutlery to a different drawer in the kitchen, you’ll typically find your hand reaching for the wrong drawer often over the days that follow. After we first learn to walk, we don’t waste conscious effort focusing on putting one leg in front of the other unless we’re trying to accommodate an injury or are walking on a difficult to negotiate surface. I suspect when we consciously think of a goal (e.g. making ourselves a sandwich), the motor area of the brain engages in response, and if we take the unusual step of deciding to WILL our motion, it’s too late -- the responsibility for the motion has already been passed on to a lower brain process. (Of course, this is just conjecture; I don’t know of any experiments that back up my view yet.) I think ultimately that the brain engages in its various processes for the same reasons that any other organ performs its function. The heart pumps to circulate blood; the more complicated brain performs a plethora of activities, one of which involves creating a virtual self, observer and decision maker. The various processes evolved in conjunction with one another and work as a system to help the organism that houses them to survive.

I apologize for my ignorance. I'm very interested in neuroscience as a layperson, so this was quite a glaring gap in my knowledge. So, what are your thoughts on what Eccles' and Libbet's work says about the mind/body problem? When I first read about back-timing, I was mainly interested in what this has to say about our notion of time. It struck me that the 'present' is an illusion we cobble together out of non-synchronous events. My personal take on the mind is that materialism is enough to explain it.

I've been interested in seeing the first paper I mentioned, because I find it so puzzling that the results of the experiment were ever taken seriously. I read Phantoms in the Brain by Vilnar Ramachandran a few years ago. He breaks down vision into all it's separate processes, and it appears that back-timing goes on when we see as well.

I'm just commenting here to bump this discussion up; I didn't want you to think I'd abandoned it.