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Discovering a New Form of Communication in the Brain

thedaily.case.edu

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Re: Discovering a New Form of Communication in the Brain

#21

Post by dr_dshiv »

avaidyam wrote: post #5
Zenst wrote: post #3

Earlier quoted context omitted.

I can't say with 100% certainty that it would have no effect, but the following may be of use: Frequency of Brain Waves State Frequency range State of mind Delta 0.5Hz–4Hz Deep sleep Theta 4Hz–8Hz Drowsiness (also first stage of sleep) Alpha 8Hz–14Hz Relaxed but alert Beta 14Hz–30Hz Highly alert and focused

This has very little relevance to the topic at hand as these refer to electroencephalogram measurements taken through a skin (scalp) patch and conductive gel.

Empirically, we'd want data on how corresponding electromagnetic pulses would affect brain activity -- there should be resonance effects, once the amplitude is high enough.

Re: Discovering a New Form of Communication in the Brain

#22

Post by dr_dshiv »

dr_dshiv wrote: post #20

When the electrical field potential changes, it changes the probability of neural firing. It's called ephatic coupling. Brain waves (local field potential) aren't just the measured average of the neural firing, but are a signal propagating force. This supports synchronization through entrainment and other resonance effects that are well characterized. Not sure why this is new, but it is great to see it in the news.

Here is the reference: https://www.nature.com/articles/nn.2727

Re: Discovering a New Form of Communication in the Brain

#24

Post by pkghost »

acrefoot wrote: post #19

Looking at the paper [0], particularly Figure 4, it looks like they cut slices then stick them back together again. This allows the signal to propagate (4.B). But when a gap of 400 microns is added (4.C), the signal doesn't propagate. I'm sure that the actual cutting causes some damage, and perfect realignment is unlikely, but I'm not sure how this is conclusive of ephaptic coupling, or how it eliminates the possibil…

Or, furthermore, by standard induction, or by standard conduction via the extracellular matrix (assuming the ECM can deal w/400microns and axons/dendrites cannot—idk if this holds)

Re: Discovering a New Form of Communication in the Brain

#25

Post by SubiculumCode »

Abstract

Slow periodic activity in the longitudinal hippocampal slice can self‐propagate non‐synaptically by a mechanism consistent with ephaptic coupling

Slow oscillations are a standard feature observed in the cortex and the hippocampus during slow wave sleep. Slow oscillations are characterized by low‐frequency periodic activity (Abstract isn't so flamboyant as the linked article

Re: Discovering a New Form of Communication in the Brain

#27

Post by tbenst »

quickthrower2 wrote: post #2

Does anyone know, how does the strength of these fields compare to the strength of the field in the brain from a wifi router at a reasonable distance? Why doesn’t all the comms gear mess with our thought processes?

Neuroscience PhD student here. The skull acts as a low-pass filter. EEG recordings are typically low pass filtered at 70Hz or lower for example. This is why you can’t decode eg speech from a EEG: the neural encoding is at a higher frequency band than can be recorded. Even though the signal is much stronger, digital comms equipment is orders of magnitude higher in frequency and does not penetrate the skull well.

Re: Discovering a New Form of Communication in the Brain

#28

Post by tbenst »

sircalvin wrote: post #26

Is this different from retinal waves? https://en.wikipedia.org/wiki/Retinal_waves

Very different. Retinal waves are a developmental phenomena and use action potentials for propagation. The study at hand attempts to disrupt all action potential transmission.

Re: Discovering a New Form of Communication in the Brain

#29

Post by est31 »

tbenst wrote: post #27
quickthrower2 wrote: post #2

Does anyone know, how does the strength of these fields compare to the strength of the field in the brain from a wifi router at a reasonable distance? Why doesn’t all the comms gear mess with our thought processes?

Neuroscience PhD student here. The skull acts as a low-pass filter. EEG recordings are typically low pass filtered at 70Hz or lower for example. This is why you can’t decode eg speech from a EEG: the neural encoding is at a higher frequency band than can be recorded. Even though the signal is much stronger, digital comms equipment is orders of magnitude higher in frequency and does not penetrate the skull well.

What about the radio signal used for MRI imaging, is it blocked by the skull as well? Or is it just strong enough to be able to penetrate the skull?

Re: Discovering a New Form of Communication in the Brain

#30

Post by tbenst »

est31 wrote: post #29
tbenst wrote: post #27

Earlier quoted context omitted.

Neuroscience PhD student here. The skull acts as a low-pass filter. EEG recordings are typically low pass filtered at 70Hz or lower for example. This is why you can’t decode eg speech from a EEG: the neural encoding is at a higher frequency band than can be recorded. Even though the signal is much stronger, digital comms equipment is orders of magnitude higher in frequency and does not penetrate the skull well.

What about the radio signal used for MRI imaging, is it blocked by the skull as well? Or is it just strong enough to be able to penetrate the skull?

fMRIs use a crazy strong magnetic field—typically >= 3 Tesla. The signal that is measured is not electrical but rather the blood oxygen level. Effectively, this is a correlate of the metabolic expenditure of nearby neurons. Wass it is also like a low-pass filter except here it’s more like 0.5 Hz or slower. On the plus, you get much improved spatial resolution
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