TalkingBrains has a posting, “Embodied or Symbolic? Who Cares?” (here). Greg Hickok is asking what exactly is the difference between embodied and symbolic cognition. He takes a nice example of a neurocomputation that is understood, the way a barn owl turns its head to a sound source. If you have not seen it before have a look at the link – it is well explained and easy to follow.

He asks:

Question: what do we call this kind of neural computation? Is it embodied? Certainly it takes advantage of body-specific features, the distance between the two ears (couldn’t work without that!) and I suppose we can talk of a certain “resonance” of the external world with neural activation. In that sense, it’s embodied. On the other hand, the network can be said to represent information in a neural code-the pattern of activity in network of cells-that no longer resembles the air pressure wave that gave rise to it. In fact, we can write a symbolic code to describe the computation of the network.

I think, however, that the example is a bit off the subject. Of course there are many examples in the brain of clear computations that could be presented in the form of a computer program or an algorithm for manipulating symbols. And it is generally assumed that the brain manipulates entities that are best called symbols: words, objects, concepts, places and the like. Even the brains great ability to work with metaphors is like substituting symbols in schemes that relate a number of symbols in a particular way. Symbols and their manipulation seems useful in understanding the brain. Symbols in the brain, of course, would always be metaphors for actual processes, but then the idea of a symbol is by its nature always a sort of metaphor standing in for whatever it is a symbol of.

But just because some, or a great many perhaps, processes in the brain can be pictured as manipulations of symbols, in ways akin to algorithms, this does not mean that the brain acts like a general computing device. Embodied cognition is quite clearly computation only in the sense of task specific processes and architecture and, not the actions of a general device. To be understood, the brain has to be seen as an integral part of the body. It is and does its part of what the body is and does. The cognitive abilities and facilities of the brain are the ones the body needs to function. If those abilities are sometimes used for arbitrary and abstract things like playing chess, this does not mean that they are not individually ‘grounded’ in the body’s requirements and limitations.

Just because some task could be done in a particular way, does not mean that it is done that way. The brain is what it is; metaphors can help us understand its workings or they can also stand in the way of understanding. They do not dictate the nature of the brain. We always should keep in mind that metaphors are somewhat limited tools.