Saturday, September 27, 2014

Lectures 3-4

Here we are establishing how neurons can "resonate" with inputs coming at particular time intervals. These input impulses must synchronize with the subthreshold oscillations of the target neuron to cause it to fire. In other words, it's not simply the sum of all input impulses and their reaching a threshold that causes firing; they must be timed in a certain way. Otherwise, an input impulse can actually cause inhibition

We can put the networks of such "resonate and fire" neurons together as in this lecture.

Let's remember the big picture. We are looking at how in individual neurons can plausibly sustain a classical-quantum interface. En route, we find that - using classical wave interference like this lecture demonstrates – they can implement important perceptual tasks that integrate-and-fire has problems implementing. This is our last lecture at this level; we then move up to groups of neurons before starting next week at the cognitive level

Please remember the connection with meditation/consciousness and gamma waves. As lucidly described in Francisco Varela's conversation with the Dali Lama, what is happening in the brain in meditation/consciousness is that global gamma waves interact with the subthreshold oscillations of the neurons. Note that the action potential is of the order of millivolts, like gamma waves; EEG, a crude measure with electrodes on the skull, picks up only microvolts. Unlike Varela, we do not believe that phase synchrony has been established – though it is plausible.

Goleman (2000) “The brain's melody” In Goleman (ed) Measuring the immeasurable Boulder Co 2000 Pp 201-210

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