4 ms·

This is very interesting to me. What are you working on?

mattkrause 8y ago
Non-invasive brain stimulation, and specifically a family of techniques called transcranial electrical stimulation (tES). These use electrodes, placed right on the intact scalp, to generate weak electric fields around the head. The hope is that (some of) it passes through the skin, skull, and CSF and affects the electrical activity of the neurons beneath. While people have gone crazy trying this for every sort of problem (basic science experiments, clinical conditions, performance enhancements), it's been unclear how tES works—or, indeed, if it works at all. The human data is a mess: some of it reports dramatic effects, others find nothing at all, and many of the experiments are...not the best to begin with. Animal data has mostly come from isolated tissue or rodents, which have very different brains and heads (the mouse skull is paper-thin, for example, and the brain is smooth, which makes it easier to get an electric field in there). To address this, we apply tES to awake monkeys playing "video games" (boring ones, but still). Monkey anatomy is pretty similar to humans, as is their behavior, but we can also monitor neural activity via tiny implanted electrodes. To my immense surprise, tES appears to have effects on both brain activity and behavior. In our 2017 study, we used direct current and looked at effects in areas on the brain's surface. Someone wrote a nice blog post about it here: https://hackaday.com/2017/11/13/shockingly-darpas-brain-stimulator-might-not-be-complete-nonsense/ https://hackaday.com/2017/11/13/shockingly-darpas-brain-stim... (which also has a copy of the paper). More recently, we managed to find some effects on individual neurons and in deep brain areas that are often targeted for neurostimulation (twitter thread here: https://twitter.com/prokraustinator/status/1102675189563822080 https://twitter.com/prokraustinator/status/11026751895638220...). Never would have gone down this road without DARPA, but it's been fun (and exhausting). I do like that it's got some fairly obvious clinical applications, unlike my PhD stuff.

Non-invasive brain stimulation, and specifically a family of techniques called transcranial electrical stimulation (tES). These use electrodes, placed right on the intact scalp, to generate weak electric fields around the head. The hope is that (some of) it passes through the skin, skull, and CSF and affects the electrical activity of the neurons beneath. While people have gone crazy trying this for every sort of problem (basic science experiments, clinical conditions, performance enhancements), it's been unclear how tES works—or, indeed, if it works at all. The human data is a mess: some of it reports dramatic effects, others find nothing at all, and many of the experiments are...not the best to begin with. Animal data has mostly come from isolated tissue or rodents, which have very different brains and heads (the mouse skull is paper-thin, for example, and the brain is smooth, which makes it easier to get an electric field in there). To address this, we apply tES to awake monkeys playing "video games" (boring ones, but still). Monkey anatomy is pretty similar to humans, as is their behavior, but we can also monitor neural activity via tiny implanted electrodes. To my immense surprise, tES appears to have effects on both brain activity and behavior. In our 2017 study, we used direct current and looked at effects in areas on the brain's surface. Someone wrote a nice blog post about it here: https://hackaday.com/2017/11/13/shockingly-darpas-brain-stimulator-might-not-be-complete-nonsense/ https://hackaday.com/2017/11/13/shockingly-darpas-brain-stim... (which also has a copy of the paper). More recently, we managed to find some effects on individual neurons and in deep brain areas that are often targeted for neurostimulation (twitter thread here: https://twitter.com/prokraustinator/status/1102675189563822080 https://twitter.com/prokraustinator/status/11026751895638220...). Never would have gone down this road without DARPA, but it's been fun (and exhausting). I do like that it's got some fairly obvious clinical applications, unlike my PhD stuff.