Sunday, 13 January 2008

Making up the Mind 3: What the brain 'knows'

So, still following up an earlier post, I'm working my way philosophically through Chris Frith's latest book: Making up the Mind. In this post I'll consider: Frith's attribution of psychological properties to the brain in chapters 1 and 2; his account of the neurological cause of hallucinatory experience in chapter 1; and in particular his rather curious theory that 'Even if all our senses are intact and our brain is functioning normally, we do not have direct access to the physical world. It may feel as if we have direct access, but this is an illusion created by our brain' in chapter 2. To spoil the story before I begin: I'll be suggesting that Frith's (strictly incoherent) attribution of psychological properties to a brain rather than a person (Hacker's 'mereological fallacy') is not always a big problem in itself. We can often cash out the metaphors. The impetus behind the bizzarre propositions of the 'our direct access to the physical world is an illusion created by our brain' sort is instead principally provided by the colluding, tacitly 'homunculuar', view that the mind or self or consciousness lies on the receiving end, as a kind of inner witness, of deliverances of neurological processes. Strike out the confused metaphysics, including that which without warrant 'objectifies' mentality (intentional relations to the environment redescribed as a domain of inner objects), and the neuropsychological facts are seen to warrant only a far more mundane description and to carry no such striking epistemological implications as Frith's text would have us believe.

Chapter 1 aims to show us how a 'damaged brain doesn't just prevent us from finding out about the world. It can also create in our minds an experience of the world that is entirely false'. I doubt anyone would be surprised at the idea that brain damage might lead to hallucination or illusion, so I shan't spend much time looking at the chapter's findings. What I want to do first are to note the colluding force of the 'mereological', 'homuncular' and 'objectifying' conceptual fallacies in the text.

Mereological, Homuncular, and Objectifying (M, H & O) fallacies:

p. 21: 'Just like a video recorder, our eyes and ears pick up information about the physical world and transmit it to our minds'. (H: minds receiving information. M: parts of bodies picking up information.)

p. 22. 'infomation from my eye (and ear and tongue, etc.) goes to my brain'. (as above)

p. 23. 'Light strikes the sensory receptors in my eye causing the receptors to send messages to brain'. (as above)

p. 23. 'Then the activity in the brain somehow creates the experience of color and shape in my mind. This mechanism is not understood at all.' (H: person is on the receiving end of a neurological process of information organisation. Unsurprisingly this mythical process has not yet been understood by science...)

p. 23. 'my mind can have no knowledge about the physical world that isn't somehow represented in the brain. [Footnote: Neurophysiologists often talk of activity in neurons "representing" something outside in the physical world. For example, neurons can be found that only become active when the eye is stimulated by red light. Activity in such a neuron is said to represent the color red.]' (Whilst it is of course people and not 'minds' that have knowledge, and whilst the brain doesn't strictly represent anything, Frith's footnote shows how he is at times aware of the metaphorical nature of such talk of 'representations in the brain'. Unfortunately this awareness does not seem to pervade the rest of the text...)

p. 26. In the 'waterfall illusion...which we can all experience, objects stay in the same place from one moment to the next, but we still see movement'. (O: of course we don't actually see movement, since nothing moves; rather it seems to us that we see movement. If however we start to imagine that seeing is actually being presented with mental objects called representations or perceptions or sensations, rather than with real things like waterfalls, then we can understand the temptation to say 'we see movement' when we only imagine movement. Frith aims to show that the neuropsychological science forces on us the opinion that 'we have no direct connection to the world'; it soon becomes clear however that this lack of connection is a function of the O, H & M conceptual fallacies which are built in anterior to the descriptions of the empirical data.)

p. 27 'Such people [as a brain-damaged man who was able to learn skills (procedural memory) whilst having chronically impaired episodic memory of the situations in which they were learnt (a bit like my own relation to my own first few years of learning to eat and talk)] show that our brain can know things about the world that our mind does not know.' (M: But why map the psychological notions of the episodic and procedural memory of persons onto the functioning of their parts (knowledge in the brain = procedural; knowledge in the mind = episodic)? Surely it is only this arbitrary decision to describe events in this unwarranted way that encourages the unusual conclusion that we and our brains are somehow at epistemic odds with one another.)

pp. 28-29 Blindsight (an ability of some people with particular neurological damage to guess correctly about the movement of objects light from which is stimulating the optic nerve, despite their taking themselves to be unable to see the objects in question) is said to involve 'my mind [having] absolutely no visual content and yet my brain [knowing] things about the visual world and [enabling] me to make accurate "guesses" about that visual world. (H: Again, I am not on the receiving end of a selection of my own brain processes; these processes do not deliver, and hence do not fail or only covertly provide, me, or my mind, with information.)

p. 29 Sub-heading: 'When the Brain Tells Lies' (M: the brain does not strictly speaking represent or misrepresent the environment. Frith had noted this correctly in a previous footnote, but now the metaphor gets lost and it is implied that the brain may tell lies.)

p. 29. 'Sometimes brain damage can cause the mind to have information about the physical world that is completely false.' (H: Mind on the receiving end of possibly damaged brain processes which are then thought of as not passing on the right information.)

p. 29. 'A deaf old lady was woken up in the middle of the night by loud music. ... Eventually she realized that the music was only in her mind.' (O: So she wasn't actually woken up by loud music. She rather awoke to a hallucination of loud music. The objectifying metaphors: placing stimuli within or before the mind where they are now perceived, start to collude with the homuncular conception of the person or mind as only in an immediate perceptual relation to this inner space.)

p. 31. 'How the Brain creates False Knowledge' (The bizarre phrase 'false knowledge' (presumably Frith means false belief?) seems to betray the fact of the unargued conceptual severing of psychological relations to the world (relations such as knowledge) even in cases where these relations are obviously constitutive of the concept (something must be true if we know it, otherwise we only believe it).)

p. 31. 'There are now many studies demonstrating that activity in the brain can create a false experience of something happening in the outside world.' (O & H: A 'false experience...' = can cause it to seem to a subject that they are experiencing something... Once experiences are turned into inner objects to be presented to an even-more-inner subject, then we will soon become only immediately aware of true or false experiences which accurately or inaccurately represent the outer world .... can we already start to see Frith's suposedly psychological conclusions falling out of the conceptual sleights of hand?)

p. 36. After considering electrical stimulation of the brain, epileptic auras, and lsd trips, Frith reports that 'I have to conclude that if my brain was damaged or its function was interfered with by electrical stimulation or drugs Iwould have to be very cautious about the knowledge I acquired about the physical world. Some kinds of knowledge who no longer be available. Some kinds of knowledge might be false and bear no relationship to the real physical world.' (O & H: Knowledge has now become not my 'openness' to the world, as Heidegger might say, not my capacity to act and think in the light of the facts, but a purely internal or mental state of affairs.)

pp. 36-37. 'Checking the reality of our experience'. (H: Once the subject is put in the epistemic predicament of being on the receiving end of the deliverances of their neurological systems, rather than in contact with the world, then it will hardly be surprising that they will seem to be faced with the possibly insuperable and definitely unenviable task of distinguishing between inner representations that have real, outer causes, and inner representations that represent neurological dysfunction.)

p. 41. By considering reaction time experiments, Helmholtz 'realised that various processes must be occurring in the brain before a representation of the an object in the outside world appears in the mind. He proposed that perception of the world was not direct, but relies on 'unconscious inferences'.' (O, H. To be sure, we are not instantly aware of changes in the external environment, and much of this lag has to do with the time taken for the brain to (metaphorically) process (metaphorical) information. But these facts don't force on us the idea that, at the end of this processing, there is some presentation of a representation by the neurological processes to the mind where it appears, nor warrants talk of 'unconscious inferences' in the brain. That description adds nothing to the facts.)

p. 43-44 Various experiments are taken to show that the putative 'experience we have of immediate and complete access to the visual scene in front of us is false. .. Many parts of the scene remain blurred and lacking in detail.' (H: Again we have the brain's putative knowledge of only small details of the visual field, along with its unconscious 'inferences' about much of it, contrasted with the perceptual fantasies that are supposedly 'in the mind'. But there's no warrant in the data for this description. As an aside - it seems to me, on the basis of my own visual experience, that 'my mind' doesn't (i.e.: I do not) experience the world as all equally completely clear. Rather what I am very directly looking at is clear, and so long as I don't cheat by looking about the place, my inability to clearly see the rest of the visual field is obvious. )

p. 49. Visual illusions are taken to demonstrate that 'my brain continues to show me false information even when I know that the information is false and even when I know what the object really looks like'. (H: My brain does not present me with information. I do not exist somehow posterior to my own brain! A natural description is: Frith is amazed that visual illusions persist even when we know they are illusions. Why not just say this?)

p. 60 'In this chapter I have shown that even an ordinary, healthy brain does not always give us a true picture of the world. Because we have no direct connection to the physical world around us, our brains have to make inferences abou that world on the basis of the crude sensations they receive from our eyes, ears, and all the other sense organs. These inferences can be wrong. Furthermore there are all sorts of things that our brains know that never reach our conscious minds.' (H, O, M: What would this conclusion read like if we removed the confused metaphysics and epistemology? How about this: 'In this chapter I have described instances of illusion and hallucination and limited perception in people with healthy perceptual systems. Furthermore I have described cases in which parts of the brain which make possible our recognition of emotion may be stimulated by visual stimuli even when we have no reportable visual experience of the emotional stimulus.' (I have left out the second and third sentences, since there seems nothing left when we remove the conceptual confusions.) Now it seems clear that the first sentence refers to some fairly mundane facts of little interest: we all know already that hallucination and illusion etc. occur in the healthy. What gave the facts the appearance of interest was the 'brain provides or plays tricks on the homuncular mind with only a selection of the details' conceptual mythologising. The final sentence however seems to report a psychological finding of genuine interest and novelty value, a finding which needs no support from the confused epistemology and metaphysics in which it is couched.)