I was having a discussion about the nature of phosphenes and it was proposed that the generation of these light like percepts could be an effect of the tms pulse being conducted down the retinal tracts, stimulating the retina, and then being passed back to the cortex for further processing.
This seems like a very slow process, and a number of sources would agree with me that this does not sound like the most likely mechanism. However, does anybody know of any recent (last 10/20 years) research that has investigated this?
Here is one interesting article that shows thresholds for eliciting phosphenes based on distance of TMS from retina: Kar K; Krekelberg B. Transcranial electrical stimulation over visual cortex evokes phosphenes with a retinal origin. Journal of Neurophysiology. 108(8):2173-8, 2012
Here is another that focused on different areas of visual cortex: Salminen-Vaparanta N; Vanni S; Noreika V; Valiulis V; Moro L; Revonsuo A. Subjective characteristics of TMS-induced phosphenes originating in human V1 and V2. Cerebral Cortex. 24(10):2751-60, 2014
And a couple of reviews papers of phosphenes not dervived from TMS: Brigo F; Storti M; Tezzon F; Manganotti P; Nardone R. Primary visual cortex excitability in migraine: a systematic review with meta-analysis. Neurological Sciences. 34(6):819-30, 2013
Schardt D; Kavatsyuk O; Kramer M; Durante M. Light flashes in cancer patients treated with heavy ions. Brain Stimulation. 6(3):416-7, 2013
You may also find this review useful: Silvanto J. Transcranial magnetic stimulation and vision. Handbook of Clinical Neurology. 116:655-69, 2013.
- Badges
- Science topic