4 ms·

Your comment doesn't add much value here. Which parts do you find implausible? Note that they are referring to CRT monitors, which do emit a strong electromagne

Your comment doesn't add much value here. Which parts do you find implausible? Note that they are referring to CRT monitors, which do emit a strong electromagnetic field

CamperBob2 4y ago
The fact that if the effect were real, it would have been noticed long before now.
- K0balt 4y ago
  It was noticed. That’s why there is a series of 50 patents or so around the basic principles of the idea dating back to the 1960s.
  - mattkrause 4y ago
    People have been mucking around with external electric fields to modulate neural activity for literally millennia! A Roman physician used electric fish to treat gout and headaches.
    - CamperBob2 4y ago
      Becauser feeling a shock from an electric eel is EXACTLY like feeling EMF from a monitor.
      - mattkrause 4y ago
        Obviously not (see numbers I crunched above) but.... a) The long and fascinating history of brain zapping only starts with fish. There were all kinds of cockamamie inventions in the 1700s-1900s, some of which were a lot of closer to this purported effect. There was also a lot of interest in using weak electric currents to improve sleep c. 1965-1975 ("electrosleep"). Anyway, I just thought it was a cool fact worth a mention. b) It was actually an Atlantic Torpedo (a ray), which is still stronger than this. Weakly electric fish might actually be in the ballpark: they only emit about a volt--and in freshwater.
danielheath 4y ago
The order of magnitude is implausible. Nervous system manipulation via magnetic field has been demonstrated to work - using field strengths of 6+ Tesla from an electromagnet that is physically touching shaved skin close to the targeted region of the brain. Getting a signal through the 30-60cm gap between monitor and user - when field strength drops off by the cube of distance - from a 60w monitor (most of which is going to luminescent output) - is not merely implausible, it's a bad joke.
- K0balt 4y ago
  That’s the whole resonant aspect of the patent. I think you must have missed that. It’s not about creating an impulse, it’s about synchronization of existing signals to create powerful stimulus.
  - jsiva 4y ago
    While resonance is possible, the resonating wave must still overcome the resistance (or whatever analagous "friction" like quantity for the system) in order for the amplitude of the wave. Given the loss from screen-to-skin propagation through air and the loss of the reflected component from air to skin transmission, it is highly unlikely that the wave can be sustained from the initial intensity of a screen.
  - mattkrause 4y ago
    You can do very surprising things to neuronal activity with weak electric fields (this is actually what I study). Some rough estimates (in brain): - 100 V/m: force almost any neuron to spike, essentially on command. Electroconvulsive therapy hits this strength or a bit less. - 20 V/m: force a neuron to spike, if it’s got the right shape and is properly aligned with the electric field. - 0.2-1 V/m: Alter the timing of spikes, so they occur sooner or later than they otherwise might. At this level, you are often competing with ongoing brain activity, so the net effect might be more or less rhythmic spiking. Can do this safely and non-invasively in humans. - 2-10 V/m: As above, but definitely win that competition so neurons tend to fire in sync with this field. Can kinda do this in awake humans, but it’s not comfortable. - 0.04 V/m: Likely upper bound on the CRT field in the brain. It’s probably even weaker.
mattkrause 4y ago
The fields here are still very weak. In the patent, they calculate the strength of the electric field produced in a few different scenarios. The largest value is 0.21 V/m at 70 com from the screen. It’s not clear to me if that’s at the skin (but in the air, where the subject’s head begins) or in it. Even assuming the stronger case, most of the induced current won’t flow into the brain: skin is so much more conductive that current applied to the head mostly shunts through the skin, and only about 20% enters the brain. (This is also the best case where the anode and cathode are both on the head; the path is much weirder with a mostly insulated person). Thus, the field strength in the brain is almost certainly much lower than 0.04 V/m. We know that fields of about 20 V/m in the brain (i.e., 500x stronger) can cause a neuron to fire, but even that’s under the best possible circumstances; You often need 40-100 V/m. Much weaker fields can alter the timing of spikes, making neurons fire a bit sooner or later than they otherwise might; I’ve shown that fields of 0.3 V/m do have an effect in monkeys. I’m loathe to say that a much smaller field has no effect whatsoever, but if so, it must be a very tiny one indeed.

Your comment doesn't add much value here. Which parts do you find implausible? Note that they are referring to CRT monitors, which do emit a strong electromagnetic field

CamperBob2 4y ago

The fact that if the effect were real, it would have been noticed long before now.

K0balt 4y ago
It was noticed. That’s why there is a series of 50 patents or so around the basic principles of the idea dating back to the 1960s.
- mattkrause 4y ago
  People have been mucking around with external electric fields to modulate neural activity for literally millennia! A Roman physician used electric fish to treat gout and headaches.
  - CamperBob2 4y ago
    Becauser feeling a shock from an electric eel is EXACTLY like feeling EMF from a monitor.
    - mattkrause 4y ago
      Obviously not (see numbers I crunched above) but.... a) The long and fascinating history of brain zapping only starts with fish. There were all kinds of cockamamie inventions in the 1700s-1900s, some of which were a lot of closer to this purported effect. There was also a lot of interest in using weak electric currents to improve sleep c. 1965-1975 ("electrosleep"). Anyway, I just thought it was a cool fact worth a mention. b) It was actually an Atlantic Torpedo (a ray), which is still stronger than this. Weakly electric fish might actually be in the ballpark: they only emit about a volt--and in freshwater.

danielheath 4y ago

The order of magnitude is implausible. Nervous system manipulation via magnetic field has been demonstrated to work - using field strengths of 6+ Tesla from an electromagnet that is physically touching shaved skin close to the targeted region of the brain. Getting a signal through the 30-60cm gap between monitor and user - when field strength drops off by the cube of distance - from a 60w monitor (most of which is going to luminescent output) - is not merely implausible, it's a bad joke.

K0balt 4y ago
That’s the whole resonant aspect of the patent. I think you must have missed that. It’s not about creating an impulse, it’s about synchronization of existing signals to create powerful stimulus.
- jsiva 4y ago
  While resonance is possible, the resonating wave must still overcome the resistance (or whatever analagous "friction" like quantity for the system) in order for the amplitude of the wave. Given the loss from screen-to-skin propagation through air and the loss of the reflected component from air to skin transmission, it is highly unlikely that the wave can be sustained from the initial intensity of a screen.
- mattkrause 4y ago
  You can do very surprising things to neuronal activity with weak electric fields (this is actually what I study). Some rough estimates (in brain): - 100 V/m: force almost any neuron to spike, essentially on command. Electroconvulsive therapy hits this strength or a bit less. - 20 V/m: force a neuron to spike, if it’s got the right shape and is properly aligned with the electric field. - 0.2-1 V/m: Alter the timing of spikes, so they occur sooner or later than they otherwise might. At this level, you are often competing with ongoing brain activity, so the net effect might be more or less rhythmic spiking. Can do this safely and non-invasively in humans. - 2-10 V/m: As above, but definitely win that competition so neurons tend to fire in sync with this field. Can kinda do this in awake humans, but it’s not comfortable. - 0.04 V/m: Likely upper bound on the CRT field in the brain. It’s probably even weaker.

mattkrause 4y ago

The fields here are still very weak. In the patent, they calculate the strength of the electric field produced in a few different scenarios. The largest value is 0.21 V/m at 70 com from the screen. It’s not clear to me if that’s at the skin (but in the air, where the subject’s head begins) or in it. Even assuming the stronger case, most of the induced current won’t flow into the brain: skin is so much more conductive that current applied to the head mostly shunts through the skin, and only about 20% enters the brain. (This is also the best case where the anode and cathode are both on the head; the path is much weirder with a mostly insulated person). Thus, the field strength in the brain is almost certainly much lower than 0.04 V/m. We know that fields of about 20 V/m in the brain (i.e., 500x stronger) can cause a neuron to fire, but even that’s under the best possible circumstances; You often need 40-100 V/m. Much weaker fields can alter the timing of spikes, making neurons fire a bit sooner or later than they otherwise might; I’ve shown that fields of 0.3 V/m do have an effect in monkeys. I’m loathe to say that a much smaller field has no effect whatsoever, but if so, it must be a very tiny one indeed.