Wednesday, November 28, 2008
Patricia Churchland
Responding to people’s request, CMBC decided to include Patricia Churchland’s talk of yesterday, “Decisions, Responsibilities, and the Brain,” in this blog. Do we have free will? Or to use Elliot Valenstein’s expression, should we blame it all on the brain? And how shall we, as a society, act accordingly?
Patricia Smith Churchland, a philosopher of mind in UC San Diego, a MacArthur fellow, and the one who coined “neurophilosophy,” is a “reductionist.” For her, as for so many who attended her talk, all human behavior can be reduced to neurobiology. But since “reductionism” carries unpleasant connotations, I prefer the word “monism,” which is in contrast with Descartes’ “dualism.” Putting word choice aside, the biological origin of human behavior frames the questions of how we make decisions, do we have free will, and what personal responsibility should society expect of us. To elaborate these questions, Churchland drew on various studies.
Are we responsible for our actions? Avner Caspi and colleagues conducted a longitudinal study of males with antisocial behavior. In 2002 they published their findings: Males with low levels of the neurotransmitter-metabolizing enzyme monoamine oxidase (MAOA) have a genetic susceptibility to childhood maltreatment. Simplistically put, one needs to have low MAOA and be abused to develop anti-social behavior. Since the anti-social adult is neither responsible for his genes nor for being abused, society is confronted with a moral dilemma: To electrocute or not to electrocute?
In 2003, JM Burns and RH Swerdlow published the case of a patient with pedophilia who raped his step-daughter. When a right orbitofronal tumor was resected, his behavior resumed to normal. Alas, only for a few months, after which the tumor started to grow again, and along with it, the pedophilic behavior. What to do? As long as the tumor is there, the step-daughter is in danger, and maybe some other girls too.
How do we make decisions? Churchland contrasted between the brain as a “causal machine” and the common belief that decisions follow a conscious sequence of “consider, intend, and act.” For example, A. Dijksterhui and his colleagues demonstrated that while decisions about simple issues can be better tackled by conscious thought, decisions about complex matters can be better approached with unconscious thought. The latter was demonstrated by giving the choice among four apartments to three groups: (i) those who had to decide spontaneously; (ii) those who decided after deliberation, and (iii) those who decided after distraction. The last group made the best choices. Supporting, as Churchland observed, the folk wisdom expressed in grandma’s advice, “Sleep on it, dear” when the decision is as complex as “Shall I marry him?”
The Brain, which played a role in most of the examples, closed the talk. With neuroimaging studies, Churchland presented how behavior can be mapped onto specific regions and circuits in the brain. She also paid attention to neurotransmitters and spoke of their prominent role in decision making. In conclusion, Churchland proposed a fuzzy-bordered multidimensional space, defined by neurotransmitters and other neurological parameters, as a region within which free will should be presumed, and responsibility should be expected.
In addition to her main theme, Churchland mentioned benefits gained from understanding the role of the brain in human psychology and behavior. On behalf of many women including herself, she spoke about the relief in linking certain moods and behaviors to neurotransmitters. She further spoke about the comfort in knowing that a certain condition is not to be blamed on the person’s character and can be corrected pharmacologically.
While I agree that many are helped pharmacologically, I have also seen how this young field can cause harm. Things get further complicated by the commercial aspect of the pharmaceutical industry. Some, like Elliot Valenstein and David Healy, wrote about it. And as our society struggles to define the sphere of free will and personal responsibilities, we should in parallel continue a cautious and skeptical discourse with the science of the brain, which while being highly promising is still embryonic and beset with many pitfalls.
All of you – neurologists, philosophers, psychologists, ethicists, and scholars of the humanities – whether you attended Patricia Churchland’s talk or not, please voice your thoughts and concerns.
