I am in the middle of a sporadic series of posts based on two recent books by Malcolm Jeeves Minds, Brains, Souls and Gods: A Conversation on Faith, Psychology and Neuroscience and Neuroscience, Psychology, and Religion: Illusions, Delusions, and Realities about Human Nature with Warren S. Brown.
Perhaps the most significant scientific challenge to Christian faith comes not from the age of the universe or the evolution of species, but rather from the findings of psychology and neuroscience. What is the relationship between brain, mind, and consciousness?
Ch.3 of Minds, Brains, and Gods opens with a question from Ben.
Since the brain is a physical system made up of atoms and molecules, how can there be any room for the top-down processes you have described that enable us to make decisions? (p. 41)
The top-down process was discussed a bit in the previous post Beware Neuromaniacs and Darwinitis. This is a serious question. It isn’t a matter of libertine free will, mind over matter, or determinism. The question is whether it makes any sense to talk about conscious decisions at all. A ball careening down a hill will bounce around with seeming randomness determined by the multitude of factors involved. It makes no sense to talk about a ball deciding to bounce to the left or the right. This video doesn’t have much to do with this post – but it is an interesting example of the apparent randomness of balls (many balls) bouncing down a hill.
Is a human any different? More complex? Okay. A much wider range of factors involved, including history, nutrition, and education? Fine. But that still doesn’t leave any freedom of decision. It is one thing to realize that we are a lot less free than we’d like to admit. After all, any freedom we have does depend on a functioning brain. It is another altogether to contemplate a total lack of freedom. Yet this is what many claim. As one eminent biologist put it “The reality is, not only do we have no more free will than a fly or a bacterium, in actuality we have no more free will than a bowl of sugar.“
Is this the clear and uncontested conclusion of science? In answer to this question Jeeves brings both chaos and the Heisenberg Uncertainty principle into the discussion, although he doesn’t hang his hat on either. These are invoked by some to remove determinism from nature. In a sense this is right, there is an intrinsic uncertainty in the quantum mechanical nature of the universe. Quantum uncertainty, chaos, and the importance of improbable events provides an intrinsic openness in nature. We could have all possible information about now, and still could not predict the future with unerring accuracy. This is an impersonal uncertainty however, not a decision making mind.
Jeeves then brings up the concept of emergence. The human brain is an unbelievably complex object. “The millions of neurons and their millions of interconnections form an ideal dynamical system. From this point of view, the elements of human neurobiology in the form of the cerebral cortex produce the cognitive properties of a whole person. (p. 45)” New causal properties emerge out of the complex, nonlinear interactions. Consciousness and perhaps a true element of “free” decision making ability may emerge out of this incredibly complex network.
The Evidence from Experiments. The argument so far is based on physics, chemistry, and perhaps metaphysics, but not on empirical evidence. This leads the discussion to Benjamin Libet’s classic experiment and its interpretation (or misinterpretation). In Ch. 5 Ben puts the question like this:
One of my friends, who is majoring in neuroscience, said that a very important paper was published in 1983 by a man named Benjamin Libet, who demonstrated that the conscious decision to make a movement came after the movement had been started. … Doesn’t that mean that any claim to decide to do this or do that is an illusion? That I’m merely reporting what my brain is already doing or has already done? (p. 54)
In reply Jeeves gives a brief description of Libet’s experiments and quotes from one of the original papers “Cerebral initiation even of a spontaneous voluntary act of the [kind] studied here can and usually does begin unconsciously. … The brain ‘decides’ to initiate or, at least, to prepare to initiate the act before there was any reportable subjective awareness that such a decision has taken place.” (B. Libet, Behavioral and Brain Sciences 8, 536, 1985) Perhaps conscious thought is not an initiator of anything but merely a reporter.
This seems to put the nail in the coffin for any real freedom of decision, but Libet’s conclusions are not the end of the story, only the beginning. Science is an ongoing discussion. No experiment is taken as the ultimate arbiter of truth, rather each result lights the way for future experiments. Jeeves does a good job of providing some insight into the process and into the kind of critical thinking that evaluates and seeks to validate or refute each new claim.
Much research has been carried on to test Libet’s ideas and conclusions with improved methods and alternative questions. Some of these support, or appear to support Libet’s results and his conclusions, but others call into question some of the underlying assumptions. Jeeves refers to several recent papers. Perhaps the most interesting was published in late 2012 by Schurger et al. in Proceedings of the National Academy of Sciences USA. (PNAS v109, E2904–E2913, 2012 Author Summary p. 16776-7) with the enticing title “An accumulator model for spontaneous neural activity prior to self-initiated movement“. The study is discussed in an article Brain might not stand in the way of free will published in New Scientist which opens “Advocates of free will can rest easy, for now. A 30-year-old classic experiment that is often used to argue against free will might have been misinterpreted.” If I am interpreting this paper correctly Schruger et al. propose a model for brain decision making where the signals interpreted by Libet as the brain preparing to move were the background signals necessary for a spontaneous decision to emerge not a prior ‘decision” by the brain.
And the search for understanding continues. The article by Schurger et al. has been cited in six papers published in the year since it first appeared. In one of these, Barking up the wrong free: readiness potentials reflect processes independent of conscious will, published in Experimental Brain Research (v229, 329-335, 2013) Schlegel et al. report no causal relationship between the readiness potential measured by Libet and willingness to move. The other papers explore additional aspects of the complex process of decision making.
Moral vs Inconsequential Decisions. Jeeves also stops to ask another question about Libet’s experiment:
I think we need to pause and ask whether experiments such as Libet’s that studied the timing of a morally neutral, simple decision, such as bending a finger, and its relation to brain processes tell us anything useful about moral decision making. What I’m saying is that there is a fundamental problem with Libet’s studies in the sense that they don’t really have any obvious relevance for the question of free will and moral responsibility. … The overwhelming phenomenological evidence from our daily lives is that we make conscious, voluntary decisions that influence the activity of our brains and bodies over minutes, days, and years, not milliseconds, and that these decisions bring real world consequences. (p. 58-59)
A handful of simple laboratory experiments are not really sufficient to negate this universal experience. We can’t separate mind, brain, and consciousness – but that still doesn’t mean that they are identical. Most of us are quite rightly convinced that we do have more free will than a bowl of sugar or a cockroach even as we are also constrained by the material and social world in which we live.
More to come … both in this series and in the continuing search for answers to the hard questions.
What questions raised by neuroscience do you find the most challenging for Christian faith?
Is the intrinsic connection between brain function and moral decision making a challenge?
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