Over the past week or two, we've been engaging philosopher of psychology Ken Aizawa on the topic of extended cognition. Ken is co-author of a book, Bounds of Cognition, in which he argues cognition is most definitely not extended in any way. We both think the other is wrong, which is always fun; I've been getting to grips with his argument and trying a few ideas out, and I wanted to take a moment to summarise where I think we're at.
Extended cognition is, roughly, the hypothesis that things other than the brain can count as parts of a cognitive system. An early Andy Clark example: you are trying to multiply two numbers together, and as part of the process you write the working out with pencil and paper. Clark wants to suggest that we should consider the pencil and paper to be part of an extended cognitive system, because the pencil and paper are doing some of the work generally thought to be part of the process (for example, relieving the memory burden on the user as they work their way through the computation).
Ken's argument is that extended cognition is essentially a fallacy: specifically, what he refers to as the coupling-constitution fallacy. He thinks Clark and others are simply making an error: while it is certainly the case that the pencil and paper are coupled to a cognitive system, this is no reason to think they constitute any part of the cognitive system. More specifically, they are not themselves cognitive processes. Non-cognitive processes can cause cognitive processes, and vice versa, via their coupling - after all, cognition needs to be about something and to be able to affect the world - but nothing about that makes the external bits constitutive elements of cognition.
Personally, I think that this isn't a general fallacy: it's merely a risk you run if you aren't careful with your task analysis. The question, though, is one what basis does Ken separate the cognitive from the non-cognitive?
There are two basic requirements that they have for what they call 'the mark of the cognitive', although they don't have anything that fulfills their requirements themselves; their argument is that extended cognition examples don't fulfill these and are thus not cognitive.
- Cognitive processes involve non-derived content, i.e. their meaning must not arise from mere social convention. The meaning of traffic signals is derived, for example; green means 'go' because we decided it does, not because green actually means 'go' in and of itself.
- Not just any process can be a cognitive process, and just because the outcome is the same doesn't make the process cognitive. A chess computer, for instance, can play a game of chess but selects it's next move via a process that is entirely unlike what chess masters seem to do. Only the end result is the same.
These are not uncontroversial, and to be honest the hypothesis of extended cognition simply rejects #2 as far as I can tell. But regardless, can these be defended?
The primary defence is, I don't think, that strong. Ken acknowledges that it is possible for a cognitive process as defined above to be 'transcranial', i.e. extended, but that it is a matter of 'contingent fact' that it isn't. Cognitive science has been looking at cognition now for 50 years, and has yet to really see anything that looks like extended cognition; worse, even the specific examples cited by people like Andy Clark and others fail to fulfill the criteria. For instance, the pencil and paper example fails because the symbols on the paper are derived content; their meaning is derived from mere convention.
There are two obvious rejoinders to this:
- Just because the philosophers you're arguing with have flawed examples doesn't kill the general idea; only the specific example. Killing a bad example is a service, no doubt: but it's not a slam-dunk to kill a single example; this is just healthy dialogue, and you may simply have identified a spherical cow error.
- More critically: this argument depends surprisingly strongly on the current state-of-the-art in cognitive science. But the science is based in a flawed premise (the assumption of mental representations, which reside in the brain), or, at least, this is what this blog has been working on demonstrating. Essentially, Ken is looking to a science that has explicitly ruled out looking for anything like extended cognition, and thinks discovering it has not found any examples of extended cognition is evidence against their existence. This is simply unconvincing.
Worse for Ken's argument, I think, is one simple fact: when Gibson abandoned the flawed premise of cognitive psychology after it consistently failed to help him explain his data, he took a simple step back and thought again about what cognition might possibly be about. He immediately found an endless stream of examples of what I think count as extended cognition. The current versions of the extended mind hypothesis are, I think, limited, because they haven't incorporated Gibson. His theories of affordances and information provides what I think is the only current show in town capable of getting extended cognition off the ground, but for some reason Gibson and ecological psychology have yet to be embraced.
As for Ken's two necessary features for any 'mark of the cognitive' - I think affordances and information gives you (1) quite readily (meaning may be relative to the perceiver but it's not mere convention), although I'm still not sure how critical non-derived meaning is. As for (2), I can simply reject it as a necessary condition, because the (radical) hypothesis of Gibson (and extended cognition) is that this simply isn't true. It isn't evidence against a radical hypothesis when it doesn't fulfill something that hypothesis explicitly rejects; so because extended cognition is functionalist about what counts, (2) seems to not be a concern.
Essentially, Bounds of Cognition seems to simply be a restatement of the features of modern cognitive science that the extended mind hypothesis wishes to reject. That's not an argument that anyone not already convinced will believe (like Putnam's Ultimate Argument for Realism, which only a realist will buy into). But Ken is right that the extended mind people need a theory about the 'mark of the cognitive' to avoid what is charmingly referred to as 'cognitive bloat'; on what basis is something not cognitive? Where is the line, if not the brain? There must be one, or else you risk trivialisation.
I've always believed that Gibson is the theory these people need: affordances and information provides precisely the structure for thinking about how cognition might possibly be extended, while ecological laws provide a mechanism to prevent that extension from being indefinite.
Adams, F., Aizawa, K. (2001). The bounds of cognition Philosophical Psychology, 14 (1), 43-64 DOI: 10.1080/09515080120033571
Adams, F & Aizawa, K (2010). The Bounds of Cognition. Boston, MA: Wiley-Blackwell.