Neurophilosophy

Abstract

Neurophilosophy is Patricia Churchland's (1986) hypothesis that the mind-brain 'problem' and related 'problems' such as those surrounding perception and cognition will be solved by advances in cognitive neuroscience.This entails that the attempts by philosophers to solve these problems by their methods of purely logical, conceptual and linguistic analysis are doomed to failure as they represent a mistaken strategy.Today is certainly an exciting time in cognitive neuroscience when we are witnessing a continual stream of important discoveries on how the brain works.The dominant themes include parallel distributed processing (PDPs), computing and information processing by nerve nets (both real and computer-simulated), Hebbian synapses, neuronal cell assemblies, the role of chaos and non-linear dynamics, unit recodings in awake behaving animals, PET scanning of ongoing human brain function in specific tasks and a wealth of basic information concerning the neurochemical and biophysical basis of learning, perception, memory, etc.Churchland also presents two other planks in her platform.The first is the belief that the Identity Theory (IT) of mind-brain relation is correct, or will be shown to be so by advances in neuroscience.The second is the recommendation that' folk' ways of talking about mind, seeing, thinking, feeling, knowing, etc. will gradually be replaced by the way that neuroscience talks about these functions.I am a firm supporter of the position that what are currently widely regarded as 'philosophical' problems about how the mind relates to its brain will eventually be solved by science and not by conceptual or linguistic analysis.But I also believe that neurophilosophy, at present, has too limited a concept of what sciences are relevant.It somewhat neglects introspection science and it assumes that contemporary physics is to all intents and purposes complete.Furthermore, it shares in the hopeless confusion that afflicts some of our very basic scientific concepts in this area.To deal with the latter first.(1) No IT theorist ever applies the theory to his or her own consciousness.For this they rely firmly on the ' folk' theory of naive or Direct Realism (DR), however much in theory they support the rival scientific theory of perception known as the representative theory (RT).At the base of this schizophrenia is the (almost) universal confusion between the ' body image' of neurology (i.e. the somatic sensory field) with the physical body itself (see Schilder, 1950; Smythies, 1953 for details).(2) This is compounded by a second (almost) universal confusion between the visual field and the stimulus field.The visual field (VF) is located in consciousness and is filled with our visual sensations -the product of the vastly complex representative mechanisms of perception.We can only observe these latter as phenomena by introspection, as in the many investigations by introspection psychologists such as Kliiver, Gregory, Vernon, myself and the whole Gestalt school.The stimulus field (SF), in contrast, consists of the physical objects in the external world that my visual field represents.The SF lies at the beginning of the complex causal chain of perception.We examine the SF field by exteroception (perceiving).We examine the VF by introspection (sensing).A good model for this is the TV screen where we can examine it as it is in itself made up of a raster of parallel coloured lines: or we can use it to observe the events in the TV studio.Since many neuroscientists call the SF the VF confusion abounds.A further complexity is provided by the many retinotopic maps in visual cortex that contain coded information about the SF.(3) Then there is much confusion about the use of the terms 'conscious' and 'consciousness'.We must distinguish between at least three quite different meanings: (i) the medico-behavioral sense, e.g.' the patient is conscious now, doctor'; (ii) the attentional sense, e.g.' she was conscious of an 1