- "Cognition has an anatomical substrate" (205).
- "Integration involves dynamic coordination (synchrony, coherence, linear and nonlinear coupling) as well as convergence" (205).
- "Stimuli and cognitive tasks act as perturbations of existing network dynamics" (206).
I find it easy for my own New Age imagination to posit some cosmic Mind emerging from the idea of cognition as network, but Sporns assiduously avoids any hint of the New Age, keeping his conversation firmly grounded in the physical anatomy of the brain and its observable and verifiable behaviors. As he says, "All cognitive processes occur within anatomical networks, and the topology of these networks imposes powerful constraints on cognitive architectures" (205).
These neural networks have "small-world attributes" that are similar to other networks that are perhaps more familiar to us: social networks, the Internet, Wikipedia, or gene networks (Small-world network). Small-world networks are characterized by clustering, which groups nodes about a more well-connected node, thus facilitating quick connectivity to most any other node in the large-scale network. This is similar to the way Google works on the Net: it is a well-connected node that reduces the hops between us as individual nodes and most any other node on the Net. It may be the way an orchestra works with clusters of violins, bassoons, and drums, with a lead violinist about whom the other violins cluster and who connects those violins to the rest of the orchestra.
This small-world architecture means that cognitive processes are both segregated and integrated. An act of knowing relies on segregated clusters of neurons firing in different regions of the brain (different instruments sounding in different regions of the orchestra), and these segregated firings are then integrated (apparently within milliseconds) into a coherent thought, much like all the sounds of the orchestra. Which brings us to Sporns' second trait of cognition as network phenomenon.
The brain apparently has a couple of mechanisms for integrating segregated patterns of neuronal firings into a coherent whole pattern. First, the brain can synchronize neuronal firings, or perhaps the better way to say this is that the neurons can synchronize themselves, much as a jazz band can find its way back to a chord progression, time signature, or tune to synchronize the various flights of solo fantasy. Then, various firings can converge in a particular firing which takes the inputs and feedforwards them as a single input.
Dynamic Coordination and Convergence
I do not understand neurophysiology well enough yet (perhaps never) to understand how synchrony and convergence work in the brain, but I understand the import: the brain is an incredibly rich orchestra of instruments which can sound or not, in unison or not, according to an internal rhythm, pitch, timbre, tone, and volume, and the brain's clusters of instruments—say, the woodwinds—can converge to create a single tone amongst the tones from the other regions of the orchestra. Every single instrument is vital to the orchestra, but no single instrument makes the orchestra. Every instrument must maintain its own integrity (the trumpet must not try to become a cello) just as surely as it must find its place in the orchestral network.
I think Sporns is using perturbation in its scientific sense as a variation or deviance in a system caused by some outside effect, and this is perhaps the most amazing trait of cognition as a network phenomenon. We in education typically think of external inputs (classroom lectures, for instance) as the most important aspect of learning, yet if Sporns is correct, then external inputs are best seen as an interruption of or as a more-or-less complimentary addition to the internal system. As I noted in a previous post, any external input must earn its place in the orchestra. An external input hardly ever totally supplants the music the orchestra of the brain is already playing, except in the case of trauma or other profound experiences. Of course, anyone who has ever tried to get the attention of twenty-five kindergarteners (or of twenty-five kindergarten teachers, for that matter) knows how difficult it is to keep them focused on your external input, whatever it is. This, it seems, is the natural state of things. Education is not the systematic, mechanical input of data into the blank data banks of students' minds; rather, education is an attempt to join and to modulate the tunes already playing in our students' minds. Surely these two processes are radically different and require radically different pedagogies.
the While I love the metaphor of the mind as an orchestra,"with clusters of violins, bassoons, and drums, with a lead violinist," many parts working in concert with one another, it will only take us so far.ReplyDelete
Accepting Sporn's comment that "cognition is a network phenomenon" we must understand the twin hemispheric nature of the brain.
Louis Cozolino's book, "The Neuroscience of Human Relationship" says, "We have learned a great deal about the brain over the last 100 years, and our ideas about the roles of each hemisphere and their working relationship with one another have become increasingly sophisticated." The right hemisphere in mammals are characterized by a bias in the control of emotion, bodily experience, and autonomic processing, The left hemisphere "usually takes the lead in semantic and conscious processing."
With the right brain in charge of emotions and the left brain tending to the cognitive we have a partnership akin to Lennon and McCarthney. However this leaves the left hemisphere to develop in a way that allows it to separate itself from the body and emotions and filter or inhibit the input of the right hemisphere.
You are correct, Theodore, that metaphors will take us only so far, but that's true of all metaphors—this one no exception. And yes, we must account for the bicameral brain, yet to my mind, this bicameralism simply adds to the magic of networks as the structural device by which consciousness is illuminated. I find it remarkable that a single thought can be spread across both hemispheres of the brain, with their substantially different wiring and processing habits. To extend our metaphor just a bit, the brain is perhaps more like two orchestras—one classical and one jazz—and to play, they must figure out how to play together.ReplyDelete
BTW, I love the Lennon/McCartney motif in your comments. It works for me.