Tuesday, March 01, 2011
Via Arts and Letters Daily, I have encountered an interesting review by Raymond Tallis of two books on neuroscience written for lay audiences. Until this morning, I had never encountered Tallis, so, although I think he makes some excellent points in his review, I know very little about his actual views on the questions the books and his review raise. With that proviso, I find him saying, on the one hand, some of the kinds of things that need to be said in many of today's discussions of science in general and neuroscience in particular; and failing to say, on the other, something that would at least provide better direction to such discussions as well as to the science itself.
As someone who would probably consider joining the Hair Club for Men if I paid too much attention to popular discussions of neuroscience, I cheered when I read the following.
... Given that the brain is an evolved organ, and, as the evolutionary biologist Theodosius Dobzhansky said, nothing in biology makes sense except in the light of evolution, the neural explanation of human consciousness demands a Darwinian interpretation of our behaviour. The differences between human life in the library or the operating theatre and animal life in the jungle or the savannah are more apparent than real: at the most, matters of degree rather than kind.Again, I am not sure what Tallis's positive views on what makes man distinct from other animals are. (What I saw in this article isn't promising.) Furthermore, while he disagrees, as I do, with the notion that our behavior is determined by evolutionary pressures, it seems to me from the review itself that he likely does so at least in part for the wrong reason:
These beliefs are based on elementary errors. Just because neural activity is a necessary condition of consciousness, it does not follow that it is a sufficient condition of consciousness, still less that it is identical with it. And Darwinising human life confuses the organism Homo sapiens with the human person, biological roots with cultural leaves. Nevertheless, the coupling of neuromania and Darwinitis has given birth to emerging disciplines based on neuro-evolutionary approaches to human psychology, economics, social science, literary criticism, aesthetics, theology and the law.
These pseudo-disciplines are flourishing in academe and are covered extensively in the popular press, in articles usually accompanied by a brain scan (described by the writer Matt Crawford as a "fast-acting solvent of critical faculties"). Only last month, David Brooks asserted in the New Yorker that "brain science helps fill the hole left by the atrophy of theology and philosophy". [bold added]
[Authors Nicholas Humphrey and Antonio Damasio] are confident that consciousness must be biological and, therefore, must have arisen because it conferred selective advantage. Given that everything of biological use which is achieved through consciousness could be achieved without it ..., it is difficult to put one's finger on what this advantage could be. Humphrey devotes several chapters to discussing the survival value of being aware of the world with which we interact. He concludes that "the simple pleasure of pure being" is enough to drive us to work harder to live, out of a "raw fear of oblivion", and this is how consciousness earns its (metabolically expensive) keep. The idea that life is such fun for conscious creatures, they do not want to let it go, is open to the simple objection that the sum total of experience may not be very pleasant. [bold added]Tallis is right to lay waste to the notion that consciousness has biological relevance basically because it makes life fun. He is wrong, however, to claim that it lacks survival value and accomplishes nothing that "could be achieved without it." (It is unclear to me whether Tallis's objection to "Darwinitis" is confined to a misapplication of evolutionary concepts to neuroscience and related fields following from determinism.)
In a 1991 paper titled, "Volition as Cognitive Self-Regulation," Harry Binswanger argues that consciousness does have biological significance precisely because it offers man something that had not otherwise arisen from evolution:
Living organisms are enormously complicated self-regulating systems. The simplest one-celled organisms are intricately complex mechanisms exhibiting levels within levels of self-regulation, all based on the genetic "program" stored in the cell's DNA. A given organism's DNA code is not random: its content has been dictated by natural selection. Natural selection acts to perpetuate those genetic units leading to phenotypic features that promote survival and to eliminate, through death, those that fail in what Darwin called "the struggle for existence."Thus, even if every behavior of biological use that conscious organisms perform could be done without it (and I am not so sure even that much is correct), the "metabolic expense" is clearly justified.
Thus, on the physical-physiological level, living action is "goal-directed" in the specific sense of being evolutionarily adapted to the attainment of conditions having survival value for the organism. If self-regulation implies a goal, then survival is the goal behind all biological self-regulation. Note that, contrary to drive-reduction and discrepancy-reduction theories (e.g., control theory), the fundamental goal is not negative, but positive: the maintenance of life is the maintenance of action. No form of stasis, including homeostasis, can be the ultimate goal of self-regulation. Living organisms regulate their physiological processes in a way that promotes their optimal survival.
But the adaptation of biological action by means of natural selection is inherently a very slow affair, with many generations normally required to make the "hard-wiring" changes to the DNA that are necessary to adapt to new environmental conditions. The higher organisms have evolved a means of enormously accelerating the adaptation of behavior to the environment: the faculty of consciousness. Consciousness allows changes to be made, in effect, in software rather than hardware. An animal that is sensorially aware of its environment is able to learn what to pursue and what to avoid, under the guidance of pleasure and pain -- natural selection having acted to coordinate the pleasure-pain mechanism with the demands of survival. Animal behavior regulated by consciousness can be adapted to survival within the animal's own life span. In addition, consciously regulated behavior allows for finer discrimination among varied environmental features: it would not be possible to build in a different preprogrammed response appropriate to every nuance of the environment confronted by the animal. Thus, consciousness adds a new level of self-regulation of behavior that greatly enhances the flexibility, range, and articulation of behavior. [reference and footnote omitted, bold added] (Binswanger 1991, pp. 154-155)