Miscellanea

For years, I've been using the phrase "brain = behavior, there isn't anything else" in my teaching as a way to get people to think more deeply about the presumptions they bring to studies of the nervous system and emphasize the distinctiveness of a non-dualist approach to understanding behavior. And it is useful for those purposes.

Among other things, the phrase triggers challenges, some answerable and others less so. Over the years, one set of challenges that has recurred has to with organisms that don't have nervous systems but clearly exhibit behavior (such as single celled organisms and plants). Another recurring challenge has to do with organisms with nervous systems (like ourselves): doesn't the body (exclusive of the nervous system) influence behavior?

For a long time, my tendency has been to brush off these two challenges in one way or another. Yes, there is behavior in organisms without nervous systems but we're concerned with those that have them. Yes, the body influences behavior but does so by its influence on the brain, which is the final common path for all influences on behavior. "Brain = behavior, there's nothing else" isn't "Truth" but a summary of observations, a way to think about things that may or may not be useful ...

A conversation with Ian yesterday persuaded me that its time to acknowledge and make explicit the limitations of that usefulness. Ian is working on "social neurobiology", the problem of how one can make sense of interactions among biology in terms of brain function. And in that context it suddenly hit me that it is clearly important to recognize that bodies can indeed be an influence on behavior independently of the brain.

How one person behaves can be influenced by another person's body in ways that may be independent of any influence of that person's body on their brain. And indeed in ways that may be independent of any influence of that person's body on anybody's brain (two bodies cannot occupy the same location whether either is represented in a brain or not). Clearly, "social neurobiology" requires a recognition that there are influences on behavior (even in organisms that have nervous systems) that do not involve the brain. One can legitimately, in such circumstances, speak of the brain not as the final common path through which all influences on behavior function but rather as one of several influences on behavior, with the body (independent of the part of it called the brain) being one of them.

Its interesting to me that the effort to move to the social level would cause me to see why it is important to explicitly admit the possibility that behavior has multiple influences, of which the brain is one. And to reflect on why I've been resistant to that notion. "Brain = behavior", as I said above, was coined to call attention to and offer an alternative to dualist presumptions, and I still think it useful for that purpose. The body is an organized material structure, like the brain, and so including it as a separate influence can be done without appeal to some additional non-material entity to account for behavior.

More importantly, though, "brain = behavior" was coined to call attention to and offer a non-dualist alternative not so much for ALL behavior (Descartes himself was happy to account for much of behavior in material terms) but rather in particular for those aspects of behavior (feeling, thinking, imagining, aspiring) that seemed most difficult to make sense of in such terms. And here the phrase seems to me still useful in its more absolute form: the brain is not one influence on our experiences of things (including ourselves), it IS our experiences; here there is indeed the brain and "nothing else" in the sense that the brain is the final common path for experiencing.

What this implies is that indeed organisms (and other things) can "behave" without a nervous system; what they can't do is have experiences of things (including themselves). What it additionally implies is that our experiences of things (including ourselves) are not actually of the things themselves but rather of ways our brain makes sense of things, ways that may differ in different people. So maybe the useful challenge isn't so much "brain = behavior" but rather "experiencing = behavior"? With the implication that not that there isn't anything else but rather that what we know of it is always subject to revision?

"We are, and we can think ..." but never know. Is that true? I don't know. Is it a good story? One that is relevant to, among other things, finding new ways to think about "social neurobiology"? I think so.