Brain Behavior and Behaving like Brains
October 13th, 2009 Rafael AlvaradoMusings on Zacks, the Hippocampus, and Kafka
NOTE: This article has been modified slightly since I originally posted it. The section on the hippocampus has been subordinated to an inline note. It is interesting (at least I think so) but not part of the main argument I’m trying to make here.
A few weeks ago I had the good fortune of seeing Jeff Zacks give a talk entitled “Film, Narration, and Cognitive Neuroscience” at the Curry School of Education at U.Va. He was invited to speak by my colleague Glen Bull as part of the school’s Tea & Technology series (every Thursday at noon in Ruffner Library if you’re around). It was an excellent talk not only for its content, but for Zacks’ gift of clarity. At no point did the science overwhelm, and the talk had the useful effect of raising lots of interesting questions in
my mind and in the minds of others.
Zacks’ thesis is relatively straightforward: human beings have the capacity to perceive events as a series of discrete segments, and this capacity to segment events is correlated with the long-term memory of those events, as well as the ability to focus on and form concepts about the goings on in an event. There are big cognitive pay-offs to performing this work of segmentation, pay-offs which (predictably) are thought to correlate to evolutionary advantage. Interestingly, the boundaries that people spontaneously define for events — such as a sequence in a French film or a film of a man washing dishes (two examples used in Zacks’ experiments) — are widely shared. Where there is variance, subjects are either older or suffering from dementia (which gives me a really good feeling about the aging process). The mechanism for segmenting thus appears to be hard-coded and deeply rooted, probably in the hippocampus.
One of the things that intrigues me about Zacks’ work is the light it sheds on the hippocampus — the odd, chili pepper shaped organ that sits in the center of the brain. Conventional wisdom (based on research with rats’ brains, it turns out) is that this region of the brain is devoted to spatial orientation and long term memory. This is what a neuroscientist friend of mine told me in the ’80s, and it’s reflected in the Wikipedia article linked to above. These two functions may appear to have no obvious relationship, but as a structural cultural anthropologist, it has always made sense to me — to my way of thinking, the hippocampus must be involved with the process of symbolization, the encoding of experiences into symbolic structures, many of whose structural armatures map onto spatial metaphors, such as left|right, up|down, etc.
Now what Zacks (or some recent research he builds on) adds to the picture is that the hippocampus also plays a role in segmentation where time perception and short term memory are in operation. So there is some sense in which the proportion — short-term memory : time :: long-term memory : space — links these core ontological dimensions at the basis of cognition. I find this idea very interesting because (1) it correlates memory with ontology, and (2) it’s the opposite of what you might think — surely time perception (perception beyond the present) involves long-term memory, and space perception would scaffold short-term memory. Perhaps in the transduction of experience into memory, such a reversal is necessary. (Or perhaps this view is the product of too philosophical a mind, one prone to seeing connections between abstractions where there are none.)
One of the most interesting parts of Zacks’ thesis is the process by which event boundaries are perceived, or rather, defined by the brain. Apparently, boundaries are inserted where the brain experiences what Zacks calls “prediction error” — when things break a pattern of repetition and thus signal to the brain a boundary that is used to construct the temporal model for the event — its typical sequence. Zacks did not mention this, but I would be surprised if this capacity were not in some way connected with the capacity of the brain to perceive information in Shannons’s sense. For prediction error is an excellent name for the newness that his negative entropy equation defines. My tentative hypothesis is that we must be wired to both perceive information in this sense, and to make use of it in the formation of perceptual structures which, in turn, become the materials from which cognitive structures are built.
Now I mention this because the response of the audience — comprised mainly of educational experts — and of Zacks himself is that one practical lesson from his research is that creators of narrative content, such as film, should make an effort to provide more obvious segmentation in their products. Clearly, if this is how the brain works, we should work this way too.
I think this is a major fallacy that pervades the reception of brain science research. People tend to assume that if the brain works a certain way, then so should we. I call it the fallacy of brain-behavior mirroring (at least until I come up with a better name), a more recent variant of the mirror of nature fallacy described by Rorty. For example, since we know (since Kant and then Gestalt psychology) that the brain actively constructs objects from experience, then, the argument goes, we should have students actively construct things too. But clearly, if the brain already works a certain way, then it works that way — in spite of, or perhaps because of, how we behave, oblivious to a detailed description of its workings. In the case of event segmentation, it seems clear to me that Zacks’ research suggests an opposite lesson — it says that people who can perceive prediction failures can also segment experiences, and thereby gain cognitively. If so, then the lesson is to get good at perceiving and creating event boundaries, which requires not pre-segmented media, but the opposite — hard to grasp art, stuff that violates expectations and rewards the perciever with a different perspective. In fact, giving students media with well defined boundaries may cause their capacity to construct boundaries to atrophy, much as caffeine causes our adrenal glands to shrink. (I know, it’s a good reason to stop drinking coffee.)
Now it turns out that some research form the University of California at Santa Barbara corroborates this view. According to the headline of the New York Times,’ piece in this work, nonsense — such as the absurdist work of Kafka — sharpens the intellect. (Another summary of this research is entitled This is Your Brain on Kafka.) Essentially, your brain has to work hard to make sense of things, which it is evolved to do, and this has the side effect of making you smarter, or at least sharper in the period following the effort to make sense where there is none. And what is nonsense but prediction failure on a large scale?
So, what is the pedagogical and media design lesson here? Learning Teaching is not about making content easy to ingest, it’s about creating environments where students can play this game of meaning formation, which isn’t always stress-free. Marketers may disagree, but they are in the business of indoctrination, not teaching.
