Thread

1. paimapi · 1790798924 · focus · HN ↗

   Bit of a sensationalist title - EEG/iEEG measurements have led to worthwhile clinical outcomes but also are an avenue for bunk pseudosccience so it pays to be careful whenever you see the words 'brain waves' paired with some large claim.

   More accurate, much less sexy title: Intracranial Recordings Uncover Spiral and Concentric Brain Waves During Memory Tasks" (study completed only on small cohorts of epilepsy patients performing constrained memory tasks).

   No inner workings revealed or laid bare, just another piece of evidence contributing to a small part of the debate in cortical electrophysiological studies on whether or not some data measures can be discarded as the downstream, messy noise of the neurons firing or actual, high-fidelity signals of activity

   1. Animats · 1790803315 · focus · HN ↗

      And still all slow stuff, 4 to 12 Hz. There must be something in the brain that clocks faster, but nobody seems to have found it yet.

      1. ACCount39 · 1790809153 · focus · HN ↗

         There are faster waves than that, but the brain just doesn't seem to be fully synchronous. It doesn't have to have a fast "clock tree" if a lot of the low timescale activity is inherently async.

         It's not at all how humans build computational devices. But humans run digital signals at gigahertz rates and do intelligent design. Nature doesn't do either.

         I suspect that there are numerous advantages to silicon computation that biological neurons can't touch, but the brain is no slouch either - it was optimized for millions of years to be good for what it does. It's very good at what it does - sometimes because of, and sometimes despite its architecture.

         It's honestly amazing that the brain even works as well as it does, given how slow neurons are. I suspect that distributed population coding that seems to be endemic to neural networks can also serve as a workaround for neurons being unreliable, slow to recover and subject to fatigue.

         1. randomImmigrant · 1790827542 · focus · HN ↗

            > if a lot of the low timescale activity is inherently async.

            But it isn’t. Every neuron runs the core circadian transcription-translation feedback oscillations. Every neuron is on a roughly 24 hour loop, synchronized by the master circadian oscillator, a clump of about 20k cells called the Suprachiasmatic nucleus.

            The faster oscillations nest under that one, including the oscillations in firing rates.

            Jet lag is when the synchrony and phase hierarchy breaks. Shift work does the same.

            Now the brain doesn’t have a fast global clock like a chip. But that’s very much part of the evolutionary design. It’s not very energy efficient to have a fast global clock. And in a system like the brain, what purpose would it serve? In the brain, timing is information. You want the slow arrival of some signal to be slow so you can actually assign some meaning to it. A fast global clock would throw those gaps away.

            In fact, there are neuromorphic and RACE logic chips that dump the global clock for the same efficiency reasons.

            1. ACCount39 · 1790839987 · focus · HN ↗

               Being clocked by the day-night cycle is very much not low timescale.

               1. randomImmigrant · 1790865718 · focus · HN ↗

                  Yes. But you don’t want synchrony in low timescale in a system like the brain, where synchrony in long time scales is constantly being negotiated between the cells, and kept in sync with the environment.

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