Thursday, May 31, 2012

Baboons Decide, Beethoven 9

Reading Latour’s recent essay reminds me that he’s done some work on baboons. I haven’t, but a particular bit of baboon behavior has been on my mind for years: collective decision-making. Here’s a passage from Beethoven’s Anvil (pp. 107-110) where I talk about baboon decision-making and compare it to the opening of the last movement of Beethoven’s Ninth Symphony.

Let’s consider an example of real social interaction, but not among humans. Let us follow Hans Kummer in observing a resting troop of baboons deciding where to go next. As you read this account you might imagine that you are a baboon situated somewhere in the middle of a troop having, say, eighty members. This is what Kummer sees from his vantage point outside the troop:
The troop performs slow on-the-spot movements, changing its shape like an undecided amoeba. Here and there, males move a few yards away from the troop and sit down, facing in a particular direction away from the center. Pseudopods are generally formed by the younger adult males and their groups. For a time, pseudopods protrude and withdraw again, until one of the older males in the center of the troop rises and struts toward one of the pseudopods. At this, the entire troop is alerted and begins to depart in the indicated direction.
There is thus a fair amount of milling about in which the group ponders its options and, after due deliberation, an elder makes a decision. The troop pulls together and heads out. By comparison you might think about the opening of the final movement of Beethoven’s Ninth Symphony: distinctly different musical ideas mill about at until one of them, the “Ode to Joy,” takes charge.

Let’s think about the older males at the group’s center. They cannot see the entire troop in a glance nor even by scanning from a fixed point of view. Each is checking out the various pseudopods and one another, glancing about, picking up indications here and there and integrating it all until one of them decides both that he’s the one to signal a direction, and what that direction is. Whatever the exact nature of the neural dynamics that performs these tasks, all this attending, updating, and integrating requires a pretty sophisticated control system to scan the scene and integrate tens or hundreds of indications about the state of the troop.

I suggest the neurodynamics of a single human musicker is comparable to the collective decision-making of this baboon troop and that humans use their Central Social Circuitry to track the music in the same way that baboons track their fellows. The troop’s milling behavior is typical of intentional systems as they “hunt” for a stable state. Unlike musicking humans, however, the baboons are not coupled in rhythmic interaction. The fact that musicking humans are coupled means that the group acts in a unified way that is impossible for a baboon troop.

Imagine then that it is May 7, 1824, and you are attending the premier of Beethoven’s Ninth Symphony at the Kärntnerthortheater in Vienna. On the stage you see not only a full symphony orchestra, with its strings, woodwinds, brass, and percussion, but also a full chorus and four solo vocalists. As the music unfolds you have to makes sense of it all. At times that is relatively easy, for only a few instruments are playing. At other times the full orchestra is playing, with the strings, brass, and woodwinds, all playing multiple parts—and then we have the chorus and soloists as well. The problem you have is not unlike that of the older males at the center of the baboon troop: You face a complex system of sonic activity and must make some integrated sense of it and maintain your own sense of direction amid all the hubbub. The difference between your group and the baboons, however, is that everyone in your group is effectively an older male scanning the scene, even the musicians.

You direct your attention here and there. Now you’re listening to the violins, then the cellos attract your interest, then the flute, which gives way to the French horn, only to be supplanted by the tympany, and so forth. Even as you attend to this or that specific musical line you remain aware of other lines.

Perhaps one thing that pulls your attention here and there is a mismatch between what is currently happening in a specific part and what you been unconsciously expecting based on what you had previously heard. One can imagine all sorts of things. If Beethoven has done his job as composer, and as conductor—despite his deafness, he is conducting the premier you are listening to—then all the interacting strands of melody will be where they need to be when you check on them. The music will flow naturally and you’ll hardly be aware of all the effort you’re expending to track all those sounds.

The parallel between our baboon troop and our Beethoven premier is not an exact one, and I have certainly pushed it to it’s limit. The principles of Equivalence and Ensemble State Collapse show how music allows a human group to function with the coherence of a single brain. Together they constitute the forge in which the Central Social Complex shapes the forms of group interaction and individual neurodynamics into a coherent culture.

At a more humble level, one where we have experimental evidence, consider the possibility that subcortical structures in your brain are treating each instrumental line as the activity of a single human actor, a virtual being. This is what Albert Bregman’s book, Auditory Scene Analysis, suggests. The human auditory system evolved to segregate the soundscape into seperate auditory streams, each of which is presumed to reflect the activities of a single causal agent somewhere in the world. Many of these causal agents are other animals, perhaps prey or predator, or fellow humans. When this system is presented with music, it operates in the same way, identifying streams and treating them as signs of actions by various agents. When you hear Beethoven’s music your brain is responding to a carnival of virtual beasts, cavorting and fighting, licking their wounds, meeting and greeting old friends, gathering at the water hole for a refreshing drink, nuzzling and snoozing the night away.

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ADDENDUM: Where do we locate the agency for the baboon troop's decision? Is it with the senior baboon who finally indicates the direction, or is it with the group that had been involved in making the decision?

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