When I look up studies about tdcs, it is always assumed that the electrical current produces polarisation only at the electrode surface. I have never been able to find any studies who clarify exactly why that happens.
If I have understood it correctly it has something to do with the fact that the current is either entering the brain or leaving it, but I don't understand why the current would have no effect "in" the brain.
Also if you perform a bihemispherical montage (such as a bitemporal or bifrontal montage), would the current stimulate areas along the longitudinal fissure, since the current is going out and into the brain at that spot.
hi,
I think you may be able to get some answers for your questions from these articles:
Singh A, Erwin-Grabner T, Goya-Maldonado R, Antal A. Transcranial Magnetic and Direct Current Stimulation in the Treatment of Depression: Basic Mechanisms and Challenges of Two Commonly Used Brain Stimulation Methods in Interventional Psychiatry. Neuropsychobiology. 2020;79(6):397-407. doi: 10.1159/000502149
Arshad Q, Siddiqui S, Ramachandran S, Goga U, Bonsu A, Patel M, Roberts RE, Nigmatullina Y, Malhotra P, Bronstein AM. Right hemisphere dominance directly predicts both baseline V1 cortical excitability and the degree of top-down modulation exerted over low-level brain structures. Neuroscience. 2015 Dec 17;311:484-9. doi: 10.1016/j.neuroscience.2015.10.045
Who says that it does??
Rashed, E. A., Gomez-Tames, J., & Hirata, A. (2020). End-to-end semantic segmentation of personalized deep brain structures for non-invasive brain stimulation. Neural Networks, 125, 233-244.
Gerry Leisman:
Thank you, that is exactly what I was looking for !
The reason I thought tdcs had no direct impact on subcortical structures was because it was implied in the studies, example: Studies that have tried to treat PTSD or anxiety disorders have almost exclusively focussed on targeting the vmpfc and dlpfc but not the amygdala. (maybe because it is difficult to target)
Another example would be the conclusions drawn from studies: let's say you perform a bilateral stimulation of the temporal cortex (T4+, T3-) and you show that it increases creativity. Some studies will conclude by saying that the right temporal cortex stimulation and left temporal cortex inhibition is responsible for this effect, even though this montage probably also affects the insula, the hippocampus, the amygdala, the thalamus, and many more...
- Badges
- Science topic