Moheb Costandi's "Body Am I"

Moheb Costandi, trained as a neuroscientist, is a science writer based in London whose work has appeared in publications including Nature, Science, New Scientist, and Scientific American. He is the author of Neuroplasticity and 50 Human Brain Ideas You Really Need to Know.

Costandi applied the Page 99 Test to his new book, Body Am I: The New Science of Self-Consciousness, and reported the following:

Page 99 of my book describes a now infamous 1983 study by Benjamin Libet et al, who measured the brain activity associated with voluntary action, and recorded what they called the 'readiness potential', which occurred several hundred milliseconds before study participants reported being conscious of their intention to perform the action:

This led Libet and his colleagues to conclude that “cerebral initiation of a spontaneous, freely voluntary act can begin unconsciously, that is, before there is any (at least recallable) subjective awareness that a ‘decision’ to act has already been initiated cerebrally.”

This particular study is often interpreted to mean that we do not have free will, or that free will is nothing more than an illusion. Subsequent studies have replicated these findings. More recently, however, some researchers have suggested that Libet and his colleagues interpreted their findings incorrectly, and that the readiness potential is actually noise that occurs while the brain is selecting from a repertoire of possible actions.

Body Am I is about the role of bodily awareness in self-consciousness. Bodily awareness consists of two main components: the sense of body ownership, or the feeling that one's body belongs to one's self, and the sense of agency, or the feeling that one is in control of one's body and is responsible for its actions. This underlies our sense of free will, or the capacity to choose between different courses of action.

Page 99 is in the chapter about agency, in a section about the control of voluntary movement, and so it does not give an accurate picture of the subject of the whole book. The work described on the page is intriguing, however: Libet et al's findings - and the concept of free will more generally - is debated by neuroscientists and philosophers to this day.

Visit Moheb Costandi's website.

--Marshal Zeringue