Peter Cariani

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As an MIT freshman, I was one of Jerry's Concourse students. He had organized the 1974-5 Concourse theme as "Mind, Machine, and Meaning". It was a major reason that I decided to come to MIT, and it was by far the most enlightening part of my MIT experience. In retrospect, we had a parade of amazing intellectuals teaching in the program and visiting us. There were lectures by Noam Chomsky, Joe Weizenbaum, Murray Eden, Dirk Struik, Lewis Mumford, and Langdon Winner.

At the time I did not understand much of what Jerry was talking about regarding the nervous system, but I think much of it must have sunk in by osmosis. At the time I also thought that the nervous system was incomprehensibly inscrutable (taking physiological psychology instead of Teuber's introduction to neuroscience also reinforced this impression that nobody really had a comprehensive grasp of any of it -- I should have taken Jerry's neuroscience course, but for reasons I don't remember never did). At various points, Jerry advised me to steer clear of a career in neuroscience because of the highly risky nature of the venture in terms of staying funding and obtaining a permanent position -- he was always dead right in his rants about the intellectually vacuous and unimaginative scientific culture that the NIH has spawned. I concentrated on problems of biological organization and complexification (emergence of new functions) and how organisms are radically different from present-day machines. In the search for open-ended adaptivity in my doctoral work, I was drawn back into theoretical neuroscience via cybernetics and neural networks and discovered the renegade literature of temporal coding.

Lo and behold, Jerry had been there with his multiple meanings in visual units, and had proposed a theory of the multiplexing neuron based on axonal branchpoints. I fortunately was able to come into neuroscience as a postdoctoral fellow working on neural coding of pitch in the auditory system. It's all timing in the form of interspike intervals, and I ended up re-inventing the CLOOGE plot in order to follow complex changes in interspike interval distributions of auditory neurons over time. If you care to look in virtually all of the other sensory modalities as well (color vision, flutter vibration, pain, smell, taste, echolocation, electroreception, etc), there are temporal patterns that covary along perceptual dimensions. So, I came to propose neural timing nets based on delay-coincidence arrays that can carry out neural signal processing on temporally-coded inputs in the form of analog pulse pattern codes. I envision an alternative conception of the brain that is signal-centric and based on temporal coding and multiplexing of signals circulating in weakly amplificative loops (such that signals can be liberated from wires and that the effective dimensionality of the signal space can be easily increased by tuning of temporal responses of neuronal assemblies).

I could never get a straight answer out of Jerry about what he thought of such ideas or of whether his friends McCulloch, Pitts, Wiener, and Licklider entertained such notions. At various points, I felt that Jerry (and perhaps Warren before him) must have had it all figured out, but at other times I think that this is (somewhat) too optimistic. Whether or not he finally comprehended it all (and the vistas of epistemology and the structure of our subjective existences that ensue), I think he was one of those people who constantly gazed in that direction and saw more than the rest of us.

We will likely be discovering more of his tracks and pondering their significance for a long time to come.

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