I have a question about your article "The thrifty brainotype" found
at: http://johnhawks.net/weblog/topics/minds/philosophy/clark-2011-thrifty-b...Instead of having the whole brain evolve as a single type (information
processing efficiency vs energy efficiency) why have only parts of the
brain be one way or the other? Given our brain has evolved from much
earlier brains, why couldn't a distant ancestor evolve a very energy
efficient brain, a later ancestor evolve a visual processing portion
that's extremely information processing efficient and then as we come
into being take these pieces and keep some pieces and discard others?Is there any reason why the issue is being discussed as a single whole
brain archetype, and not as a piecemeal "some of this and some of
that" type?
Thanks so much for this question. I agree entirely, on a functional and evolutionary level of analysis, there is no reason why different cognitive systems should be constrained in the same way. I take Clark's model as a heuristic of how "brain" might be organized along information processing lines, but I think the heuristic fails at the level of a whole organism.
In contrast, the "expensive brain" heuristic really does apply at the organismal level because brain tissue uses energy, and the brain mass is a useful (if imprecise) way of considering energy consumption.
I don't think we can break up the brain into functional modules uncritically, but there are only certain ways in which it is useful to consider it as a whole.
