One and something year old Jonas is playing games. Self-designed, highly entertaining games - at least for his two biggest fans. The semantics of the game are sometimes difficult to assess, but the behavior has a clear, observable, repeatable structure and it is clearly something new that was not witnessed before.
For instance, Jonas will walk to his mother, slap her knees with both hands, laugh with excitement, turn round, walk to his father who sits at the other side of the table, slap his knees with both hands, laugh with excitement, and repeat the procedure again and again, walking back and forth between his two parents. I had not seen this kind of structured, repetitive behavior before, it emerged somewhere in the last week or weeks. The behavior is marked by some arbitrarily sequence of acts that is being repeated over and over.
And now, the little man is asleep. As fatherly pride slowly fades, philosophical reflection appears on the scene.
If we try to describe what we, observers, experience while watching the child, we would quickly choose some appropriate words for what we experience to be 'a new behavioral capacity'. In the example above the words are 'playing games'. Cognitive science excels in the next step, which is to replace these words with other words that supposedly catch the 'essence' of the observed phenomenon. We can expect analyses such as this one: Playing games, is "essentially" the ability to express and follow a rule-structure.
At the same time, neuro-scientists are carefully investigating what has changed in the neural organisation of the brain, since it is clear, at least to these scientists, that new behavioral capacities must be caused by significant changes in brain organisation.
Suppose the brain-scientist indeed discovers a structural brain change that is reliably associated with the onset of 'game playing' behavior in small children. Would that be proof of the theory that the new neural organisation is responsible for "the ability to express and follow a rule structure"?
I'm afraid not.
What we have, as a fact, is that there is a brain change that correlates with a behavioral change. The behavior is complex, it is real, it is located in space and in time, it emerges within a physical and social environment. The 'game' is played using a physical body with physical properties. It is played in a context of social relations between father, mother and child. It emerged out of a situation in which the mother and father were sitting opposite each other at a table from which the child was just leaving after having had dinner. Within this *practical, real* situation, a brain change had its effect. Game playing was the result.
Abstracting away from the observed phenomenon to the underlying 'essence' is a dangerous activity. It is often grounded in values, beliefs and perceptions of the observer. It is also constrained by the language in which the abstraction is expressed.
But even if the abstraction is a valid one, there is no proof whatsoever that the brain change is in itself corresponding to (representing) this 'essence' that is described by the abstraction. It could be that the brain change, in itself, is something very different. Something that, in itself, has nothing to do with 'following a rule-structure'. The newly observed behavior of game playing, and its associated 'essence' - following rules - might be emerging only when the 'updated' brain is operating in an appropriate physical and an appropriate social environment, preceded by an appropriate history of actions.
Cognitive science has a strong history of what Churchland calls 'vertical analysis', in which behavior is broken down into several, vertical, 'columns', corresponding to the classic 'faculties' of mind, and its modern heirs, the computational-representational 'modules'. "Rule-following" is such a module. But in the process of breaking down the observed phenomenon into meaningful abstractions (essences), we can also choose to cut reality in horizontal slices. A horizontal slice corresponds to a full-blown, functional, complete sensorimotor loop in which parts of the brain, the body and the environment take part. Structurally new behaviors that clearly mark cognitive developmental phases, such as the emergence of 'game playing', might be explained by the development of a new second order influence within the brain upon such a horizontal, existing, and operational, sensorimotor cycle. The brain change thus comprises not of a new module that represents the new 'capacity', but it comprises of a new *bias* upon the existing agent-environment interaction.
As they say in pop-music: the band and the audience make the show.
