Monday, August 06, 2018

Embodied cognition


Knowledge is not only in the brain. With this statement I don’t mean in this blog the “extended mind thesis”, which says that a part of the mind is outside the brain in the agent’s world. For instance, you have stored a mailing list in your computer and you know in which file it is, so you don’t need to have the addresses in your mind. No, in this blog I mean with my statement that your knowledge is in your whole body. This thesis is called “embodied cognition”. Last week I discussed already an instance of it.
Actually the thesis doesn’t represent one view. As the Stanford Encyclopedia of Philosophy says in its introduction to the theme: “Embodied cognitive science encompasses a loose-knit family of research programs in the cognitive sciences”. The family shares its critique against traditional approaches but each member tries to find her own solutions. Here I cannot even try to give a full treatment of the theme, but I’ll give some illustrations so that you get an idea what it is about.
My description of embodied cognition last week was rather vague. This one from the Stanford Encyclopedia of Philosophyis much clearer: “Cognition is embodied when it is deeply dependent upon features of the physical body of an agent, that is, when aspects of the agent’s body beyond the brain play a significant causal or physically constitutive role in cognitive processing.” The definition says that there is more knowledge in the body than we find in the grey matter in the head. One of my favourite examples to show how this can be is the case of a runner. Broadly it is so that there are two types of runners: sprinters and long-distance runners. Of course, everybody can choose to become a sprinter and train as hard as s/he can and so become better and better. Nevertheless whether s/he’ll become a good sprinter depends not only on the training but also on the features of his or her muscles. Just as we have an inborn capacity for language learning, we have an inborn capacity for becoming a good sprinter. A person with the type of muscles for a long-distance runner will never become a good sprinter. And the same story for the athlete who wants to train for a 5K or a marathon. In other words: Your legs have a kind of knowledge about running a sprint or running a long distance. However, this is not the whole story, for talented or not, everybody will become better in the chosen speciality by training. The muscles become stronger, the blood transport in the legs improves etc. And the next time you are going to train this increased capacity is still there. So your legs have “learned” to adapt to the training (just as you’ll become better by practicing a language you are learning). You have got more knowledge but this knowledge is not in your head but in your muscles.
I want to add another example, which I have taken from the website of Psychology Today (see Sources below). The web post there explains that there are two very different kinds of robots, here exemplified bij Honda’s ASIMO and the Boston Dynamics Big Dog. Let me quote:
“Honda’s ASIMO literally implements a traditional cognitive, computational approach. Everything it does is the output of complex internal programmes which control everything he does. Honda are fond of trotting him out to dance, run, and climb stairs; he can do all this, but it’s very fragile. Minor disruptions throw him entirely (e.g. a minor error in foot placement and he falls ...; hide his pre-set landmarks with a little clutter and he completely fails to navigate his way across a room). He’s slow, and inefficient; if you knock him, he needs time to recompute his behaviour or else he falls, and he often doesn’t have the time. [The] Boston Dynamics Big Dog[, on the other hand, can] walk over rough, uncertain terrain while carrying heavy loads[. The designers] knew that the computational strategy was too slow and cumbersome. So they instead built a robot with springy legs and joints that mimic the kind of dynamical systems seen in animal quadrupeds. Big Dog has very little brain; the specific movements he produces ... emerge from the interaction between his moving legs, the surface he’s on and any other forces acting on him. If you knock Big Dog, he doesn't need to recompute his behaviour; he simply responds to the new force and the details are left up to his anatomy (his leg moves where it goes because that’s the way it’s built).” (italics mine) This is not only the way Big Dog moves. As stressed by me in the quotation Big Dog’s walking is copied from the way animals walk and, I assume, man walks as well.
The embodied cognition thesis says that knowledge is not only in the brain but in the whole body. I presented here two cases that illustrate the thesis, but there is a growing number of studies that substantiate the view. I’ll mention only a study by Shaun Gallagher, one of my favourite authors in the field (see Sources below). But if it works this way, it has consequences for our self-understanding and, for instance, for our idea of free will (a theme also discussed by Gallagher). It looks as if your body can behave against “your” will. But do we also say so when you drive a self-driving car? Of course not.

Sources
- For the Stanford Encyclopedia of Philosophy: https://plato.stanford.edu/entries/embodied-cognition/#toc
- Gallagher, Shaun, How the body shapes the mind. Oxford: Clarendon Press, 2005

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