| Functionalism (psychology) |
Article Index for Functionalism |
Information AboutFunctionalism (psychology) |
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DEFINITION Turing (1950) was among the first to note that the human brain could be analogied to the Computer , which has been designed to carry out certain functions. In particular, whilst computers are physical devices with electronic substrate that perform computations on inputs to give outputs, so brains are physical devices with neural substrate that perform computations on inputs which produce behaviours. While this may be fictional rather than fundamental it helps show that functionalism is the theoretical level between the physical implementation and behavioural output (Marr, 1982). Therefore, it is different from its predecessors of Cartesian Dualism (advocating discrete mental and physical substances) and Skinnerian Behaviourism and Physicalism (declaring only physical substances) because it is only concerned with the effective functions of the brain, through its organization or its ‘software programs’. More formally, functionalism says that “mental states are constituted by their causal relations to one another and to sensory inputs and behavioural outputs” ( Block , 1996). PROBLEMS WITH FUNCTIONALISM Inverted Spectra Consider an individual named Kate being asked to tick a box on a red and green piece of paper. Assume that the red paper Kate ticks her response on appears green to Kate because she had undergone surgery as an infant and had her ‘green’ and ‘red’ vision inverted, although she was still brought up to identify objects that appear to her as green (really red) as red and vice versa. Indeed, if Kate were to have a twin who did not have the operation they would both report that the piece of paper was red, even though Kate was experiencing green. This thought experiment using ‘ Inverted Spectra ’ (Block and Fodor, 1972) is claimed to present a Prima Facie argument against functionalism because Kate and her twin experience two states that are functionally commensurate but qualitatively dissimilar (Block, 1994). The notion that Kate and her twin can have two different Qualia (the experience of experience) but remain functionally indifferent is used to demonstrate that functionalism is not robust enough to explain individual differences in qualia. A rejoinder to this argument is that Kate and her twin are not actually functionally equivalent because of Kate's surgery as an infant. Block (1980) also argues against the functionalist proposal of Multiple Realizability , where hardware implementation is irrelevant because only the functional level is important. Block considers if the billion or so neurons in a brain were given functionally equivalent electronic substitutes fitted with radios to communicate and distributed to the Chinese population if China would have qualia. He thinks it could not and argues that functionalism is inadequate accordingly.However, if functionalism is correct there can be no objection to this scenario. The Chinese Room The problems of functionalism are most clear when its role in Consciousness is examined. If functionalism is correct then all thinking, including the feeling of consciousness, can be explained by computations ( Penrose , 1994). The Chinese Room is a thought experiment by Searle . Simply, a person who speaks only Chinese sits inside of a room being passed notes in English to which he gives responses based on some algorithm (e.g., for x give y). On the other end of the 'system' (i.e. the output) a person is receiving conversationally appropriate English responses to their responses and yet the Chinese man (who speaks no English) understands nothing except that for x input he is to give y. This thought experiment by Searle (1980) shows how functionalism could be false because in acting as the ‘program’ executing instructions the Chinese man lacks Intentionality and is only concerned with syntactic procedures rather than semantic content. Searle pre-empted critics who claimed the ‘system’ as a whole understands by positing that if the Chinese man remembered all the possible instructions and went about his life he still would not understand English. If functionalism is to explain all mental processes it encounters problems in explaining how meaning can be derived from pure computation. Inductive Functionalism This concerns the issue that accurately knowing what functions the brain is executing at any one time is difficult to know. For example, in a psychological investigation some variable, such as word length, might be manipulated to measure the effect on another variable, say, reaction time from which some inference about reading might be made. This describes the inductive Scientific Method , where reasoning is made from observed facts. However, if the example is continued and the investigation finds that longer words take longer to respond to there are several interpretations that can be made. One is that the word recognition is serial, letter by letter. Another is that it is parallel (letters are processed all at once) but longer words require more lexical ‘post-recognition’ processing. The details here are not important; however, what is important is that inductive functionalism is bad at accurately determining what functions are performed by the brain. This is a serious problem for functionalist cognitive science because where multiple explanations exist it may be impossible to ascribe one correctly or, worse, possible to ascribe one incorrectly. Rejoinders As has been shown one of the central arguments against functionalism is that it fails to account for the Qualitative aspects of minds or Qualia . However, such arguments intuitively assume qualia exist independently of brain function. Some functionalists believe China would have qualia but that due to the size it is impossible to imagine China being conscious (Lycan, 1987). Indeed, it may be the case that we are constrained by our Theory Of Mind (e.g. Baron-Cohen, Leslie and Frith, 1985) and will never be able to understand what Chinese consciousness is like. Therefore, if functionalism is true either qualia will exist across all Hardware or will not exist at all but are illusory ( Dennett , 1990). However, whichever of these is true the problem of obtaining semantic content from syntactic operations remains. The ‘systems reply’ is a rejoinder, which claims as a whole the system understands Chinese and that the ‘processor’ does not just as a Neuron would not (Harnad, 2001). However, the issue is still moot. Finally, inductive functionalism is problematic because of the risk of false conclusions. These will be greatly reduced, but not avoided, by continuous empirical hypothesis-testing and peer criticism. Furthermore, a multidisciplinary approach integrating neuroscience, psychology and evolutionary biology will allow more data to converge on theories and models which will reduce the risk (Mundale and Bechtel, 1996). However, of all the arguments made against functionalism the risk of false conclusion is the most damaging and, unfortunately, is largely unavoidable.............. REFERENCES
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