5 ms·

Ex-BCI research student here. The nerves that control your arm are wired directly into your central nervous system and can active your muscles in direct respon

Ex-BCI research student here. The nerves that control your arm are wired directly into your central nervous system and can active your muscles in direct response to action potentials fanned out from a single neuron. These noninvasive technologies pick up aggregate signals from hundreds of thousands of neurons all firing pseudo-randomly, filtered spatially by the dura (thick layer of membrane that protects the brain), skull, flesh, skin and hair. A more "HN" analogy would be like comparing a directly wired Ethernet connection (nerves connected to the CNS) to a side channel attack on an air-gapped system (noninvasive EEG). While randomly running background processes (normally) won't affect the data transmitted to the network, they will absolutely foil most side channel attacks.

zaptrem 5y ago
This is a great analogy.
westurner 5y ago
What about with realtime NIRS with an (inverse?) scattering matrix? From https://www.openwater.cc/technology https://www.openwater.cc/technology : > Below are examples of the image quality we have achieved with our breakthrough scanning systems that use just red and near-infrared light and ultrasound pings. https://en.wikipedia.org/wiki/Near-infrared_spectroscopy https://en.wikipedia.org/wiki/Near-infrared_spectroscopy Another question: is it possible to do ah molecular identification similar to idk quantum crystallography with photons of any wavelength, such as NIRS? Could that count things in samples? https://twitter.com/westurner/status/1239012387367387138 https://twitter.com/westurner/status/1239012387367387138 : > ... quantum crystallography: https://en.wikipedia.org/wiki/Quantum_crystallography https://en.wikipedia.org/wiki/Quantum_crystallography There's probably some limit to infrared crystallography that anyone who knows anything about particles and lattices would know about ?
- omgitsabird 5y ago
  A couple of studies linked in Wikipedia for this use (one retracted): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049706/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049706/ Retracted: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002593 https://journals.plos.org/plosbiology/article?id=10.1371/jou... Table with resolution differences between different techniques: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116487/table/T1/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116487/table/T...
  - westurner 5y ago
    > Table with resolution differences between different techniques: Looks like MEG has the best temporal and spatial resolutions.
- AussieWog93 5y ago
  > What about with realtime NIRS with an (inverse?) scattering matrix? I've purged a lot of the knowledge from that time from my brain, but from what I recall fNIRS takes a long time (on the order of multiple seconds) to take a single reading. It also only really shows which regions of the brain are receiving more blood supply. While a huge improvement in spacial precision over EEG, it's still not anywhere near the same level of precision that a directly-wired nerve has. That doesn't mean it's useless technology, just probably not viable for the low-latency, high-accuracy control you'd want for a military drone. >Another question: is it possible to do ah molecular identification similar to idk quantum crystallography with photons of any wavelength, such as NIRS? Could that count things in samples? I have absolutely no idea about molecular identification or quantum crystallography, so probably can't give you a good answer on that one.
  - mattkrause 5y ago
    The newer systems can sample much faster (10-100 Hz), but they're still limited by the fact that they're measuring a hemodynamic signal that lags behind neural activity.
    - westurner 5y ago
      Which other strong and weak forces could [photonic,] sensors detect? IIUC, they're shooting for realtime MRI resolution with NIRS; to be used during surgery to assist surgery in realtime. edit: https://en.wikipedia.org/wiki/Neural_oscillation#Overview https://en.wikipedia.org/wiki/Neural_oscillation#Overview says brainwaves are 1-150 Hz? IIRC compassion is acheivable on a bass guitar.
- cknizek 5y ago
  Most NIRS systems use continuous-wave (CW) systems detecting blood oxygenation/chromophore concentration. I say this because, in the time domain, you're looking at 5-7 seconds to see changes in cerebral oxygenation. It's also noteworthy that you're dealing with huge amounts of noise, very low resolution, and are limited to the cortical surface. This limits the applications in the BCI-domain. I'm currently researching the feasability of fast optical imaging. This has to be done in the frequency domain, but may yield temporal resolution in the milliseconds. The downside is finding an incoherent light source that's able to be modulated fast enough to detect the scattering changes.
  - westurner 5y ago
    You mentioned "time-domain", and I recalled "time-polarization". From https://twitter.com/westurner/status/1049860034899927040 https://twitter.com/westurner/status/1049860034899927040 : https://web.archive.org/web/20171003175149/https://www.omnisense.org/2016/10/electronic-warfare-patents-directed-energy-weapon-patents-v2k-patents.html?m=1 https://web.archive.org/web/20171003175149/https://www.omnis... "Mind Control and EM Wave Polarization Transductions" (1999) > To engineer the mind and its operations directly, one must perform electrodynamic engineering in the time * domain, not in the 3-space EM energy density domain.* Could be something there. Topological Axion antiferromagnet https://phys.org/news/2021-07-layer-hall-effect-2d-topological.html https://phys.org/news/2021-07-layer-hall-effect-2d-topologic... : > Researchers believe that when it is fully understood, TAI can be used to make semiconductors with potential applications in electronic devices, Ma said. The highly unusual properties of Axions will support a new electromagnetic response called the topological magneto-electric effect, paving the way for realizing ultra-sensitive, ultrafast, and dissipationless sensors, detectors and memory devices. Optical topological antennas https://engineering.berkeley.edu/news/2021/02/light-unbound-optical-topological-antennas/ https://engineering.berkeley.edu/news/2021/02/light-unbound-... : > The new work, reported in a paper published Feb. 25 in the journal Nature Physics, throws wide open the amount of information that can be multiplexed, or simultaneously transmitted, by a coherent light source. A common example of multiplexing is the transmission of multiple telephone calls over a single wire, but there had been fundamental limits to the number of coherent twisted light waves that could be directly multiplexed. Rydberg sensor https://phys.org/news/2021-02-quantum-entire-radio-frequency-spectrum.html https://phys.org/news/2021-02-quantum-entire-radio-frequency... : > Army researchers built the quantum sensor, which can sample the radio-frequency spectrum—from zero frequency up to 20 GHz—and detect AM and FM radio, Bluetooth, Wi-Fi and other communication signals. > The Rydberg sensor uses laser beams to create highly-excited Rydberg atoms directly above a microwave circuit, to boost and hone in on the portion of the spectrum being measured. The Rydberg atoms are sensitive to the circuit's voltage, enabling the device to be used as a sensitive probe for the wide range of signals in the RF spectrum. > "All previous demonstrations of Rydberg atomic sensors have only been able to sense small and specific regions of the RF spectrum, but our sensor now operates continuously over a wide frequency range for the first time,"
deleted 5y ago
[deleted]

zaptrem 5y ago

This is a great analogy.

westurner 5y ago

What about with realtime NIRS with an (inverse?) scattering matrix? From https://www.openwater.cc/technology https://www.openwater.cc/technology : > Below are examples of the image quality we have achieved with our breakthrough scanning systems that use just red and near-infrared light and ultrasound pings. https://en.wikipedia.org/wiki/Near-infrared_spectroscopy https://en.wikipedia.org/wiki/Near-infrared_spectroscopy Another question: is it possible to do ah molecular identification similar to idk quantum crystallography with photons of any wavelength, such as NIRS? Could that count things in samples? https://twitter.com/westurner/status/1239012387367387138 https://twitter.com/westurner/status/1239012387367387138 : > ... quantum crystallography: https://en.wikipedia.org/wiki/Quantum_crystallography https://en.wikipedia.org/wiki/Quantum_crystallography There's probably some limit to infrared crystallography that anyone who knows anything about particles and lattices would know about ?

omgitsabird 5y ago
A couple of studies linked in Wikipedia for this use (one retracted): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049706/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4049706/ Retracted: https://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002593 https://journals.plos.org/plosbiology/article?id=10.1371/jou... Table with resolution differences between different techniques: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116487/table/T1/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8116487/table/T...
- westurner 5y ago
  > Table with resolution differences between different techniques: Looks like MEG has the best temporal and spatial resolutions.
AussieWog93 5y ago
> What about with realtime NIRS with an (inverse?) scattering matrix? I've purged a lot of the knowledge from that time from my brain, but from what I recall fNIRS takes a long time (on the order of multiple seconds) to take a single reading. It also only really shows which regions of the brain are receiving more blood supply. While a huge improvement in spacial precision over EEG, it's still not anywhere near the same level of precision that a directly-wired nerve has. That doesn't mean it's useless technology, just probably not viable for the low-latency, high-accuracy control you'd want for a military drone. >Another question: is it possible to do ah molecular identification similar to idk quantum crystallography with photons of any wavelength, such as NIRS? Could that count things in samples? I have absolutely no idea about molecular identification or quantum crystallography, so probably can't give you a good answer on that one.
- mattkrause 5y ago
  The newer systems can sample much faster (10-100 Hz), but they're still limited by the fact that they're measuring a hemodynamic signal that lags behind neural activity.
  - westurner 5y ago
    Which other strong and weak forces could [photonic,] sensors detect? IIUC, they're shooting for realtime MRI resolution with NIRS; to be used during surgery to assist surgery in realtime. edit: https://en.wikipedia.org/wiki/Neural_oscillation#Overview https://en.wikipedia.org/wiki/Neural_oscillation#Overview says brainwaves are 1-150 Hz? IIRC compassion is acheivable on a bass guitar.
cknizek 5y ago
Most NIRS systems use continuous-wave (CW) systems detecting blood oxygenation/chromophore concentration. I say this because, in the time domain, you're looking at 5-7 seconds to see changes in cerebral oxygenation. It's also noteworthy that you're dealing with huge amounts of noise, very low resolution, and are limited to the cortical surface. This limits the applications in the BCI-domain. I'm currently researching the feasability of fast optical imaging. This has to be done in the frequency domain, but may yield temporal resolution in the milliseconds. The downside is finding an incoherent light source that's able to be modulated fast enough to detect the scattering changes.
- westurner 5y ago
  You mentioned "time-domain", and I recalled "time-polarization". From https://twitter.com/westurner/status/1049860034899927040 https://twitter.com/westurner/status/1049860034899927040 : https://web.archive.org/web/20171003175149/https://www.omnisense.org/2016/10/electronic-warfare-patents-directed-energy-weapon-patents-v2k-patents.html?m=1 https://web.archive.org/web/20171003175149/https://www.omnis... "Mind Control and EM Wave Polarization Transductions" (1999) > To engineer the mind and its operations directly, one must perform electrodynamic engineering in the time * domain, not in the 3-space EM energy density domain.* Could be something there. Topological Axion antiferromagnet https://phys.org/news/2021-07-layer-hall-effect-2d-topological.html https://phys.org/news/2021-07-layer-hall-effect-2d-topologic... : > Researchers believe that when it is fully understood, TAI can be used to make semiconductors with potential applications in electronic devices, Ma said. The highly unusual properties of Axions will support a new electromagnetic response called the topological magneto-electric effect, paving the way for realizing ultra-sensitive, ultrafast, and dissipationless sensors, detectors and memory devices. Optical topological antennas https://engineering.berkeley.edu/news/2021/02/light-unbound-optical-topological-antennas/ https://engineering.berkeley.edu/news/2021/02/light-unbound-... : > The new work, reported in a paper published Feb. 25 in the journal Nature Physics, throws wide open the amount of information that can be multiplexed, or simultaneously transmitted, by a coherent light source. A common example of multiplexing is the transmission of multiple telephone calls over a single wire, but there had been fundamental limits to the number of coherent twisted light waves that could be directly multiplexed. Rydberg sensor https://phys.org/news/2021-02-quantum-entire-radio-frequency-spectrum.html https://phys.org/news/2021-02-quantum-entire-radio-frequency... : > Army researchers built the quantum sensor, which can sample the radio-frequency spectrum—from zero frequency up to 20 GHz—and detect AM and FM radio, Bluetooth, Wi-Fi and other communication signals. > The Rydberg sensor uses laser beams to create highly-excited Rydberg atoms directly above a microwave circuit, to boost and hone in on the portion of the spectrum being measured. The Rydberg atoms are sensitive to the circuit's voltage, enabling the device to be used as a sensitive probe for the wide range of signals in the RF spectrum. > "All previous demonstrations of Rydberg atomic sensors have only been able to sense small and specific regions of the RF spectrum, but our sensor now operates continuously over a wide frequency range for the first time,"

deleted 5y ago

[deleted]