Why In The World Would You Try Deep Brain Stimulation?

That’s what I remember thinking the first time I figured out that they were talking about opening your skull and planting electrodes into your brain. Then I thought… Imagine being so desperate that that would seem like a sensible next step in your course of treatment. And then I thought… Wouldn’t it be amazing if tDCS, Focused Ultrasound, or now Temporal Interference, could replicate the results without the surgery.

Recently the always excellent Invisibilia podcast covered DBS as applied to depression and OCD. We hear from the patient, her boyfriend and the doctors involved. I have a completely new understanding of the procedure and its effects. I highly recommend a listen to this episode.

Higher, Better, Stronger, Faster — Elise Hu, NPR

Nicely done (for a media outlet) six week experiment to test efficacy of HaloNeuro‘s Halo Sport tDCS device. Elise’s takeaway is that she wishes the effect was a little more dramatic. But her trainer tells her that extra 1-1/2″ is actually significant. Certainly in pro sports settings I’m sure it would be. Nice overview of hypothetical understanding of how tDCS works. She also interviews HaloNeuro co-founder Daniel Chao and Olympic volleyball athlete Kim Glass. Elise on Twitter

Why Can’t We Stimulate The Surface of the Brain Non-Invasively?

No doubt a naive question, but something I’m super-curious about.

Certain neurosurgeries require patients to remain awake in order to communicate with the surgeon. In this paper,  Cingulum stimulation enhances positive affect and anxiolysis to facilitate awake craniotomy, the authors demonstrate that stimulation of “the left dorsal anterior cingulum bundle was discovered to reliably evoke positive affect”. A low current stimulation evoked a smile and a “really good feeling”.

Many years ago, perhaps even as a boy, I saw this clip of Wilder Penfield eliciting memories from brain surgery patients, and it really stuck with me. Probably the notion of one’s entire stream of consciousness existing somewhere in the brain waiting to be unlocked with a bit of stimulation is incorrect, but nevertheless, to hear these actual recordings of patients suddenly recalling events from their past is fascinating.

My question is, Why can’t non-invasive brain stimulation, like tDCS, evoke similar responses to those outlined in these two videos? If it’s that tDCS stimulates too broadly, then perhaps something like Temporal Interference (where stimulation occurs at the point where two frequencies meet) could be used to stimulate these areas. Certainly an experiment worth thinking about.