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Some of the things Musk has claimed are probably physically impossible using the device Neuralink has constructed. For example, there is indeed a treatment for

Some of the things Musk has claimed are probably physically impossible using the device Neuralink has constructed. For example, there is indeed a treatment for depression that involves stimulating parts of the brain using electrodes. But the parts you need to reach are way in there[1]. Neuralink's device is not capable of reaching these areas in its current form. However I'm way out of my depth on this. The best I can do is listen to skepticism and try to evaluate it on its merits vs. the things that Musk says and his track record of over-promising. [1] https://www.shockmd.com/2008/01/20/6-different-locations-for-deep-brain-stimulation-in-depression/ https://www.shockmd.com/2008/01/20/6-different-locations-for...

nvrspyx 4y ago
I won't speak at all on Neuralink, but you don't necessarily need to stimulate that deep into the brain directly. You can piggyback off existing functional connectivity between that deep area and an area closer to the cortical surface. Functional connectivity is when one area sends activation or inhibitory signals to another area when stimulated. This is the mechanism behind using transcranial magnetic stimulation (TMS) to treat depression ([0] as just one example) despite TMS's shallow stimulation depth. Using the functional connectivity also provides an avenue of sending inhibitory signals, not just activation signals. With that said, it requires functional imaging (fMRI) to determine the functional connections. Functional connectivity also isn't indefinitely static and it does change over time. . 0: https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2019.19070720 https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2...
- nvrspyx 4y ago
  I should add that it's much more nuanced and complicated than how I've explained. Along with determining if a functional connection is excitatory or inhibitory, you need to ensure its direction as well because functional connections aren't necessarily bidirectional. You also want to be confident in how stimulating the target endpoint will affect the functional connection over time. It may potentially strengthen it (think "training") or weaken it (think "desensitizing"), thus potentially affecting the efficacy of the stimulation over time. As with most scientific fields, knowledge is built up one step at a time and you need to stand upon the shoulders of prior work before producing an application with confidence.

nvrspyx 4y ago

I won't speak at all on Neuralink, but you don't necessarily need to stimulate that deep into the brain directly. You can piggyback off existing functional connectivity between that deep area and an area closer to the cortical surface. Functional connectivity is when one area sends activation or inhibitory signals to another area when stimulated. This is the mechanism behind using transcranial magnetic stimulation (TMS) to treat depression ([0] as just one example) despite TMS's shallow stimulation depth. Using the functional connectivity also provides an avenue of sending inhibitory signals, not just activation signals. With that said, it requires functional imaging (fMRI) to determine the functional connections. Functional connectivity also isn't indefinitely static and it does change over time. . 0: https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2019.19070720 https://ajp.psychiatryonline.org/doi/full/10.1176/appi.ajp.2...

nvrspyx 4y ago
I should add that it's much more nuanced and complicated than how I've explained. Along with determining if a functional connection is excitatory or inhibitory, you need to ensure its direction as well because functional connections aren't necessarily bidirectional. You also want to be confident in how stimulating the target endpoint will affect the functional connection over time. It may potentially strengthen it (think "training") or weaken it (think "desensitizing"), thus potentially affecting the efficacy of the stimulation over time. As with most scientific fields, knowledge is built up one step at a time and you need to stand upon the shoulders of prior work before producing an application with confidence.