How does the physical brain give rise to the psychological mind? How do the laws of mental life emerge from the brain?
The hypothesis of all those who examine the brain as "organ of the mind" is that a close enough analysis of the workings of the brain would, if we also had the key to psychophysiology, lead to a knowledge of consciousness. The psychophysiological hypothesis, at least in its narrow version of it, seeks point-to-point mappings of brain, consciousness, and memory.
If this research program is interpreted as a metaphysics, it runs up agains the tradition privelege of mind over body in Western thought. In Descartes' dualism, all phenomena could be explained in terms of two distinct and irreducible principles, mind and matter, their only connection being the intervention of God. Thomas Hobbes contested this notion, claiming that mental states were just particular physical states. This doctrine is materialism. Alfred North Whitehead, in Science and the Modern World, attributes the duality of mind and matter to the scientific ideas of the seventeenth century. He sees the concepts of life, organism, function, instantaneous reality, interaction, and order of nature as the collective Achilles' heel of the system. (p.57)
a neuron and its connections
In order to understand consciousness, should one examine the workings of neurons and their interactions? This is the thesis of the "new materialists" such as Francis Crick, for whom " 'You,' your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact "no more" than the behavior of a vast assembly of nerve cells and their associated molecules " (The Astonishing Hypothesis, p.3) For Crick, the scientific task of a scientific approach to consciousness is to determine the neural correlates of its various forms.
In cognitive science, the term mind refers to an information-processing description of the functioning of an organism's brain. (how dreary ) Knowledge of the "hardware" is not necessary for understanding information processing. Nor can the information-processing description be reduced to a physical one. Instead, the two levels of description are complementary.
For David Pinker, "the mind is a system of organs of computation, designed by natural selection to solve the kinds of problems our ancestors faced in their foraging way of life, in particular, understanding and outmaneuvering objects, animals, plants, and other people" (How The Mind Works, p. 21) Pinker unpacks this statement to say that the mind is what the brain does; (specifically, the brain processes information , and thinking is a kind of computation) that the mind is organized into modules or mental organs, each with a specialized design that makes in an expert in one arena of interaction with the world; that the modules' basic logic is specified by our genetic program; that their operation was shaped by natural selection to solve the problems of the hunting and gathering life of our ancestors, and that these various subproblems were all elements of the main task of their genes, to maximize the number of copies that made it to the next generation. But while Pinker describes thinking as computation, he does not believe the computer is a good metaphor for the mind.
In his work on vision, David Marr claims that "there must exist an additional level of understanding at which the character of the information-processing tasks carried out during perception are analyzed and understood in a way that is independent of the particular mechanisms and structures that implement them in our heads." (Vision, p.19) Marr describes vision as an example of a complex information-processing system that cannot be understood as a simple extrapolation of its elementary components. For Marr, neuroanatomy relates primarily to the level of analysis that pertains to "hardware implementation," and psychophysics is related to a middle level of algorithm and representation.
For Marr, an algorithm is likely to be understood more readily by understanding the nature of the problem being solved than by examining the mechanism. Steven Pinker describes the problem of vision as "reverse optics," which is what engineers call "an ill-posed problem," in that it has no solution. While optics is easy, inverse optics is impossible -- just as it is easy to multiply some numbers and announce the product, but impossible to take the product and announce the numbers that were multiplied to get it. For Pinker, the brain supplies the missing information (p.28) but in a way that has been evolved to deal with living in a certain kind of world. For evolutionary psychology, there has been the evolution of a mesh between the principles of the mind and the regularities of the world, such that our minds reflect many properties of the world. (see also gestalt )
David Chalmers suggests that scientists postulate conscious experience as a fundamental property of the universe, like gravity, space-time, and electromagnetism. He believes that the "hard problems" of conciousness cannot be solved otherwise, referring to subjective feelings or " qualia." But isn't this a modern restatement of Cartesian dualism? V.S. Ramachandran's account of qualia makes the philosophical problem into one of translation. He provides a kind of Darwinian account of qualia, stressing their functional requirements as part of decision-making based on perceptual representations. He describes qualia as irrevocable inputs, held in short-term memory, which are involved in time-sensitive choices.
For Daniel Dennett, conciousness is an epiphenomenon, a side-effect of the competition of mental contents. cf non- localization of memory in Israel Rosenfeld, The Invention of Memory and Daniel Dennett's rejection of the centralized brain center.
For Colin Mcguinn, understanding consciousness may remain forever beyond human understanding, because of human cognitive limitations. He says that for humans to grasp how subjective experience arises from matter might be like "slugs trying to do Freudian psychoanalysis -- they just don't have the conceptual equipment." (see thinking)
Is it possible to describe the subjective character of experiences in a form comprehensible to beings incapable of having those experiences? For Suzanne Langer (in Mind: an Essay on Human Feeling) close attention must be paid to the many "forms of feeling" inextricably involved with all the vital processes of life, such as breathing, getting hungry, eliminating, falling asleep and emerging out of sleep, or feeling the coming and going of emotions and thought.
The philosophical teaser of the"brain in a vat" question has been reformulated in the light of contemporary technological projections. Until recently, the philosophical paradox that we would not be able to tell if we were "brains in vats" given the proper set of stimuli was only a "thought experiment.".The actual possibility seemed unlikely, and in a profound sense, made no difference. In Mind Children, Hans Moravec looks forward to the day when a similar transmutation could take place from human brains into computers, conferring immortality on individuals freed from the aging of "meat". The real possibility would make a difference that was not just philosophical. At least for now, however, we do not engage in everyday life in the belief that our experience is a trick played on us by our brains. At this level, our common sense is still evident in our trust of our bodies. We have to put some trust in the accuracy of these perceptions and beliefs. If they did not have some basis, chances are we would be dead.
The " bottom up" approach of designing artificial life which Rodney Brooks proposals for insect-like robots that are "Fast, Cheap, and Out of Control," reasserts the link between mind and body, because thinking is directly linked to movement and is built up from populations of simple instructions.