Brain Bits

I never got on with the idea of parts of the brain, like “this part is for imagining, this part is for counting”. Though I also never really explored why I didn't like the idea. Perhaps because it seemed like a strangely simplistic way of explaining how something so weird and blobby could work.

I kinda imagined the brain as a big mess, where there might be *some* dominance in certain areas for certain activities, but I never saw a convincing case for the idea that if you lost part of a brain (lost? As if you've casually misplaced a lump of gooey grey matter), that the processing that was there disappeared with it.

My mental image was more of a messy, interdependent system that could compensate for damaged or missing parts (within reason), with parts of the brain able to compensate and change depending on the requirements and development of the brain-holder.

Anyway, I recently found a language for this, in the terms “softly assembled systems” and “interaction-dominant dynamics”. Here's an explainer from Anderson:

Certain systems, such as an automobile or a laptop computer, are composed of a series of parts, each of which has a particular role that it fulfills. Other systems, such as flocks of birds, are more fluidly put together. In the latter case, it doesn’t matter which particular birds are part of the flock—any old bird will do—and each bird is capable of taking up each posi-tion in the flock. Indeed, during flight each bird will take up multiple positions in the flock. The flock is softly assembled, in that it is composed of a temporary coalition of entities,engaged in collaborative task. Some softly assembled systems exhibit interaction-dominantdynamics, as opposed to component-dominant dynamics. In component-dominant dynam-ics, behavior is the product of a rigidly delineated architecture of modules, each with prede-termined functions; in interaction-dominant dynamics, on the other hand, coordinatedprocesses alter one another’s dynamics and it is difficult, and sometimes impossible, toassign particular roles to particular components. Sometimes softly assembled systems exhibiting interaction-dominant dynamics are called synergies

I've discovered I've always felt like the brain is a softly-assembler system with interaction-dominant dynamics! And that it's a pretty solid idea:

Most recently, Anderson (2010) and Anderson and Pessoa (2011) conclude from a review of 1,469 fMRIexperiments in 11 task domains (including vision, audition, attention, emotion, language,mathematics, memory, abstract reasoning, and action execution, inhibition, and observation)that a typical anatomical region (as delimited, for example, by Freesurfer) is involved insupporting multiple tasks across nine separate cognitive domains. Even relatively smallpieces of neural real estate (equivalent to 1⁄1000th of the brain) typically support tasksacross more than four of these domains.

So how does the brain do things? One idea is that it's the activation patterns between areas of the brain that matters, and that newly formed human behaviours (talking compared with, like, eating) use wider-spread internal brain activation patterns. E.g. we're (as a species, over thousands of years) finding ways to use the basic machinery of our simplistic mammalian brains for our more amazing purposes:

Anderson demonstrated that the differencesbetween cognitive domains are marked less by differences in the neural circuitry devoted toeach, and more by the different patterns of cooperation between mostly shared circuitry(Anderson, 2008). In addition, it appears that the functional complexes supporting tasks innewer—more recently evolved—cognitive domains utilize more and more widely scatteredcircuitry than do the complexes supporting older functionality like vision and motor control(Anderson, 2007, 2008)

Which, taken to a conclusion that I've made up and couldn't find a quote for from someone more informed, suggests that nurture is vitally important in helping the brain form those activation pathways.