Cerebellum and cognition (qua philosophy of mind)
In philosophy of mind, a relatively popular view about the relationship between “mind” and “brain” is termed functionalism. This view claims that the brain is like a computer processor, and the mental states we experience are like the programs run by the computer. A recent paper focuses upon the potential support for this family of theories which could emerge from new analysis of the cerebellum:
Frings, M., Maschke, M. and Timmann, D. (2007) ‘Cerebellum and cognition - viewed from philosophy of mind’, The Cerebellum, 1 - 7.
The cerebellum is known to be involved in movement, but it’s possible that this part of the brain also plays a role in cognition. Rather than arguing for or against this hypothesis, the authors take this as a given to see what sort of impact it might have upon functionalist views of the mind. Suppose, they ask, that we replace the cerebellum with some kind of Turing machine. The cerebellum has, according to Timman and Maschke, “a very set structure with conspicuously uniform neuronal networks” which makes the idea relatively realistic. Unfortunately, we still have to connect the cerebellum to the rest of the brain, which is vastly more difficult.
In terms of a functionalist viewpoint, the cerebellum’s activities are not bounded merely by input/output into the cerebellum itself, but by its connection to the cerebrum. The cerebellum of humans is not significantly different structurally than in its evolutionary predecessors, but (if the theory of cognition is correct), it plays a different role for us than they.
Timman and Maschke conclude, then, that this potential finding lends support to Searle’s Chinese Room Argument against functionalism. The Chinese Room Argument invites us to imagine a person inside of a room with a rule book and set of Chinese characters in a basket. He passes characters through a slot to the outside, in response to characters given to him. However, he does not speak or understand Chinese, but is merely following rules. Functionally, though, he is in every way acting as if he does–so Searle concludes that this view of the mind is missing something important.
A typical rejoinder argues that the system (man, rulebook, characters), for all intents and purposes, understands. The authors believe that if the cerebellum’s connections to the cerebrum play such a crucial role in cognition, then this reply is dead in the water. Here’s why they think this: equate the cerebrum with the English-speaking person, the cerebellum with the room, rule book, characters, etc. The brain qua system is united in one room, “understands” Chinese, but the person has no knowledge of the content of the characters, only rules. So he cannot ascribe any meaning to them.
So far, the article has been expressly limited to cognition. In contrast, the problem of consciousness is difficult to reduce to functional/material explanation. Even if we can explain emotional modulation by virtue of cerebellar functions (as is being done in autism, for example), “there remains a fundamental difference between a dysmetric movement and the phenomenal experience of an altered emotion.” The explanatory gap is still lurking in our science, even though our terminology seems to say otherwise.
The major conclusions of this short piece are:
1. The cerebellum is not like a Turing machine or suitable for prosthetic replacement, although it initially seems so.
2. Because replacing a cerebellum would require replacing the entire brain, “cerebellar research does not support the argument of multiple realizability put forward in favor of functionalism.”
3. Since the cerebellum non-human animals does not involve cognition but (possibly) in humans it does, then this can only be explained by anatomy, not information processing.
4. Finally, if we assume the cerebellum is involved in cognition, but no loss of mental states is shown in people with cerebellum damage, then we cannot reduce mental function to the cerebellum.
In my next post, I’ll investigate their argument against functionalism and see if it holds up under scrutiny.
The conclusion is that there isn’t empirical support for functionalism based upon this research.
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