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I had super high hopes when Bryan was developing a MEG (magnetic and electrical signals) helmet... now that it's basically fNIR with some fancy scattering, nodd

I had super high hopes when Bryan was developing a MEG (magnetic and electrical signals) helmet... now that it's basically fNIR with some fancy scattering, nodding to you Dr. (infrared basically), he's left my hopes high and dry. BOLD signals are great, but they are based on oxygenation of blood, which is a latent, and at best a second order effect for metabolic activity, which is then reference to be brain activity... I'll have to dig up the studies, but if you've been paying attention on HN and elsewhere we are starting to find that 'strengthening' neurons with a fiber like substance around it reduces the electrical activity required to achieve the same neural-result. Combine this with recent papers saying that mice smell a rose with a different, migrating, set of neurons each time... and you end up thinking, damn... this really isn't the right approach to BCI / mind reading.

namlem 5y ago
The article was sparse on the details, does the Flux helmet not use OPM-based MEG? I agree that it is by far the most promising technology for neuroimaging, though I wasn't aware of anyone working on it aside from a couple of university labs in England. We're never going to get the kind of fidelity we need for advanced diagnostics (much less mind reading) with fNIRS or fMRI. Bringing down the cost of MEG tech is the only realistic way forward.
asgraham 5y ago
> 'strengthening' neurons with a fiber like substance around it reduces the electrical activity required to achieve the same neural-result. I think you're talking about myelination, which is a result that's been around for quite a while. Myelination probably wouldn't confound this kind of "brain reading" because it's relatively stable, i.e. changes occur over the course of days at a minimum, and supposedly infrequently in the fully developed brain. Any "brain reading" will have to account for changing neural efficacies, as that's what learning is, and the tricky stuff would be learning on the scale of seconds or minutes (e.g. changes in synaptic efficacy) rather than things like myelination. That being said, while the conventional wisdom is that myelin is stable over the course of months/years in the adult brain, perhaps it's results suggesting more ongoing myelin plasticity that are the more recent results you're referring to (a general trend in recent neuroscience). If so, I'd love to see those studies. Disclaimer: I'm soooo skeptical of this kind of extracranial signals being used for "unlocking the brain's secrets." There's lots you can do with those signals, sure, just look at the past decades of EEG research. But they seem to be wanting to go far deeper with fundamentally the same technology, which seems like a dicey proposition to me. So while I think there are lots of potential critiques of this technology, I just don't think myelination is the critique to go with.
DoingIsLearning 5y ago
> BOLD signals are great, but they are based on oxygenation of blood, which is a latent, and at best a second order effect for metabolic activity, which is then reference to be brain activity... To add to this fNIR is only really able to penetrate a marginal depth of a few centimeters of periphery cortical tissue. Even if it was a perfect signal, the functional information it would provide would not give us a full picture of all the sub-cortical activity.

namlem 5y ago

The article was sparse on the details, does the Flux helmet not use OPM-based MEG? I agree that it is by far the most promising technology for neuroimaging, though I wasn't aware of anyone working on it aside from a couple of university labs in England. We're never going to get the kind of fidelity we need for advanced diagnostics (much less mind reading) with fNIRS or fMRI. Bringing down the cost of MEG tech is the only realistic way forward.

asgraham 5y ago

> 'strengthening' neurons with a fiber like substance around it reduces the electrical activity required to achieve the same neural-result. I think you're talking about myelination, which is a result that's been around for quite a while. Myelination probably wouldn't confound this kind of "brain reading" because it's relatively stable, i.e. changes occur over the course of days at a minimum, and supposedly infrequently in the fully developed brain. Any "brain reading" will have to account for changing neural efficacies, as that's what learning is, and the tricky stuff would be learning on the scale of seconds or minutes (e.g. changes in synaptic efficacy) rather than things like myelination. That being said, while the conventional wisdom is that myelin is stable over the course of months/years in the adult brain, perhaps it's results suggesting more ongoing myelin plasticity that are the more recent results you're referring to (a general trend in recent neuroscience). If so, I'd love to see those studies. Disclaimer: I'm soooo skeptical of this kind of extracranial signals being used for "unlocking the brain's secrets." There's lots you can do with those signals, sure, just look at the past decades of EEG research. But they seem to be wanting to go far deeper with fundamentally the same technology, which seems like a dicey proposition to me. So while I think there are lots of potential critiques of this technology, I just don't think myelination is the critique to go with.

DoingIsLearning 5y ago

> BOLD signals are great, but they are based on oxygenation of blood, which is a latent, and at best a second order effect for metabolic activity, which is then reference to be brain activity... To add to this fNIR is only really able to penetrate a marginal depth of a few centimeters of periphery cortical tissue. Even if it was a perfect signal, the functional information it would provide would not give us a full picture of all the sub-cortical activity.