The Extended Mind, by Andy Clark and David J Chalmers: "Where does the mind stop and the rest of the world begin?" This paper proposes that there are functions of the mind that are embedded in the physical world, a so-called "active externalism".
The premise: "Epistemic actions alter the world so as to aid and augment cognitive processes such as recognition and search. Merely pragmatic actions, by contrast, alter the world because some physical change is desirable for its own sake (e.g., putting cement into a hole in a dam. [...] Epistemic action, we suggest, demands spread of epistemic credit. If, as we confront some task, a part of the world functions as a process which, were it done in the head, we would have no hesitation in recognizing as part of the cognitive process, then that part of the world is (so we claim) part of the cognitive process.
"In the cases we describe, by contrast, the relevant external features are active, playing a crucial role in the here-and-now. Because they are coupled with the human organism, they have a direct impact on the organism and on its behavior. In these cases, the relevant parts of the world are in the loop, not dangling at the other end of a long causal chain."
(And I can't help thinking of the basal ganglia, acquiring learning to encode into their long, long unconscious loops, but now being looped round a nanometre-scale circuit in a computer's CPU.)
An analogy: "The extraordinary efficiency of the fish as a swimming device is partly due, it now seems, to an evolved capacity to couple its swimming behaviors to the pools of external kinetic energy found as swirls, eddies and vortices in its watery environment. These vortices include both naturally occurring ones (e.g., where water hits a rock) and self-induced ones (created by well-timed tail flaps). The fish swims by building these externally occurring processes into the very heart of its locomotion routines. [...]
"Now consider a reliable feature of the human environment, such as the sea of words. This linguistic surround envelopes us from birth. Under such conditions, the plastic human brain will surely come to treat such structures as a reliable resource to be factored into the shaping of on-board cognitive routines. Where the fish flaps its tail to set up the eddies and vortices it subsequently exploits, we intervene in multiple linguistic media, creating local structures and disturbances whose reliable presence drives our ongoing internal processes. Words and external symbols are thus paramount among the cognitive vortices which help constitute human thought."
(Except our vortices - words - persist over time in the environment, can be shared and depended on. And it's not just words: it's objects, arrangements, dynamic processes, behaviour of others.)
And to finish: "And what about socially-extended cognition? Could my mental states be partly constituted by the states of other thinkers? We see no reason why not, in principle."
(Agreed! Intelligence/expectances (that is, hard-coded assumptions of 'the environment') is articulated as behaviour, which folds into the environment, and becomes extelligence (the ubiquitous computing term for external knowledge). Extelligence then constrains behaviour in the same way as intelligence does... it's habit encoded into the universe - into other people - a cybernetic governer, in a way, part of the causal loop -- time-bound like individual learning, or evolution. Oh, I wrote an Upsideclown on the subject of extelligence a while back.)