"Two simple pendulums that swing with perfect regularity can, when yoked together, move in a chaotic trajectory. Given that the billions of neurons in our brain are each like a pendulum, oscillating back and forth between resting and firing, and connected to 10,000 other neurons, isn’t chaos in our nervous system unavoidable?...
Chaos seems unqualified as a mechanism of biological information processing, as it allows noise to propagate without bounds, corrupting information transmission and storage.
At the same time, chaos has its advantages. On a behavioral level, the arms race between predator and prey has wired erratic strategies into our nervous system.1 A moth sensing an echolocating bat, for example, immediately directs itself away from the ultrasound source. The neurons controlling its flight fire in an increasingly erratic manner as the bat draws closer, until the moth, darting in fits, appears to be nothing but a tumble of wings and legs. More generally, chaos could grant our brains a great deal of computational power, by exploring many possibilities at great speed...
The philosopher Gilles Deleuze and psychiatrist Felix Guattari contended that the brain’s main function is to protect us, like an umbrella, from chaos. It seems to have done so by exploiting chaos itself. At the same time, neural networks are also capable of near-perfect reliability, as with the beating heart. Order and disorder enjoy a symbiotic relationship, and a neuron’s firing may wander chaotically until a memory or perception propels it into an attractor. Sensory input would then serve to “stabilize” chaos. Indeed, the presentation of a stimulus reduces variability in neuronal firing across a surprising number of different species and systems,11 as if a high-dimensional chaotic trajectory fell into an attractor. By “taming” chaos, attractors may represent a strategy for maintaining reliability in a sensitive system."
I really want to learn more about chaos theory, especially as it relates to the brain. I randomly first encountered it in a talk by a guy trying to use twitter to measure emotional responses around different issues. He demonstrated that emotion typically operates chaotically, but if you choose your issue carefully you can find patterns.
The idea of chaotic dynamics is not that it's completely random, but instead that the rules and interactions are so complex that it isn't possible to predict what the outcome will be based on the initial conditions.
But I read a paper **find paper, was that Chen's???** suggesting that the nervous system has both chaotic and non-chaotic states, or sort of has non-chaotic elements that measure the chaotic elements and then react when the chaos enters a certain state. Because, again, the chaos isn't random, it is reacting to stimuli and it is therefore providing information about both that stimulation and about the rules operating on the chaotic system at the time of the stimulation. And our brains have, at some level, some knowledge of how to read that.
Which is, like, wow.
Related: Constrained chaos in evolution (an article from the same site that has phenomenal graphics); neural circuits might be introducing chaos even at the most basic level - in this paper, in rod cells (was it rods?) in our eyes that can detect single photons and were always thought to guard against the chaos of single-photon sensitivity
FB: "Chaos is not the same as disorder. While disordered systems cannot be predicted, chaos is actually deterministic: The present state of the system determines its future. Yet even so, its behavior is only predictable on short time scales: Tiny differences in inputs result in vastly different outcomes. Chaotic systems can also exhibit stable patterns called “attractors” that emerge to the patient observer. Over time, chaotic trajectories will gravitate toward them. Because chaos can be controlled, it strikes a fine balance between reliability and exploration. Yet because it’s unpredictable, it’s a strong candidate for the dynamical substrate of free will."
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