2 replies to this topic

[3AlarmLampscooter]

I've recently been reading about the fascinating work Allan Snyder has done with repetitive transcranial magnetic stimulation (rTMS) to temporarily induce savant abilities in normal people.

I've recently started work reverse engineering TMS hardware, and I'm intent on repeating his results.

For those uninitiated, a bit of background info:
https://en.wikipedia...Savant_syndrome
https://en.wikipedia...tic_stimulation

Some previous threads on savant syndrome:
http://www.longecity...ndrome-article/
http://www.longecity...avant-syndrome/
http://www.longecity...ectromagnetism/
http://www.longecity...credible-brain/

Old rTMS proposal:
http://www.longecity...lation-methods/

A couple of Snyder's papers on experiments in healthy volunteers:

Savant-like skills exposed in normal people by suppressing the left fronto-temporal lobe
Snyder AW, Mulcahy E, Taylor JL, Mitchell DJ, Sachdev P, Gandevia SC.
Journal of Integrative Neuroscience, Vol 2, No. 2, 149-158 (2003)

The astonishing skills of savants have been suggested to be latent in everyone, but are not normally accessible without a rare form of brain impairment. We attempted to simulate such brain impairment in healthy people by directing low-frequency magnetic pulses into the left fronto-temporal lobe. Significant stylistic changes in drawing were facilitated by the magnetic pulses in four of our 11 participants. Some of these "facilitated" participants also displayed enhanced proofreading ability. Our conclusions are derived from 11 right-handed male university students, eight of whom underwent placebo stimulation. We examined performance before, during and after exposure to the stimulation.

Savant-like numerosity skills revealed in normal people by magnetic pulses
Snyder A, Bahramali H, Hawker T, Mitchell DJ.
Perception. 2006;35(6):837-45.

Oliver Sacks observed autistic twins who instantly guessed the exact number of matchsticks that had just fallen on the floor, saying in unison "111". To test the suggestion that normal individuals have the capacity for savant numerosity, we temporarily simulated the savant condition in normal people by inhibiting the left anterior temporal lobe of twelve participants with repetitive transcranial magnetic stimulation (rTMS). This site has been implicated in the savant condition. Ten participants improved their ability to accurately guess the number of discrete items immediately following rTMS and, of these, eight became worse at guessing as the effects of the pulses receded. The probability of as many as eight out of twelve people doing best just after rTMS and not after sham stimulation by chance alone is less than one in one thousand.

His review the cognitive phenomenon behind it, citing a lot of good further neuroscience reading:

Explaining and inducing savant skills: privileged access to lower level, less-processed information
Allan Snyder
Phil. Trans. R. Soc. B 27 May 2009 vol. 364 no. 1522 1399-1405

I argue that savant skills are latent in us all. My hypothesis is that savants have privileged access to lower level, less-processed information, before it is packaged into holistic concepts and meaningful labels. Owing to a failure in top-down inhibition, they can tap into information that exists in all of our brains, but is normally beyond conscious awareness. This suggests why savant skills might arise spontaneously in otherwise normal people, and why such skills might be artificially induced by low-frequency repetitive transcranial magnetic stimulation. It also suggests why autistic savants are atypically literal with a tendency to concentrate more on the parts than on the whole and why this offers advantages for particular classes of problem solving, such as those that necessitate breaking cognitive mindsets. A strategy of building from the parts to the whole could form the basis for the so-called autistic genius. Unlike the healthy mind, which has inbuilt expectations of the world (internal order), the autistic mind must simplify the world by adopting strict routines (external order).

An interview of his with Psychology Today: http://www.psycholog...ty-allan-snyder

My reddit thread on proposed DIY rTMS savant induction: https://reddit.com/r...aled_in_normal/

Another reddit thread with serious discussion of savant syndrome: http://www.reddit.co...shallow/ceucdhw

tl;dr it's the Savant-o-tron

Any input would be welcome. Thus far I've been trying to figure out optimal pulse forming network, coil and power supply design (whether electrolytic capacitors with clamping diodes are suitable for main energy storage or non-polar ones are required, etc).

I'd especially love to hear input from anyone who's made (or tried to make) an rTMS machine before.

I intend to post full plans once I'm up and running.

[adamh]

Why would you be sure the impulses inhibited that portion of the brain? Might it instead have stimulated it or brought out these abilities? That seems at least as likely as inhibiting it and that somehow bringing out the abilities.

I have heard about TMS as a method to help people sleep. I even looked into getting one of those machines but they are hugely expensive and potentially dangerous in inexperienced hands. They do make a toy version that runs off a 9v battery and they ask ridiculous amounts even for that. A real machine uses large amounts of electricity to produce the pulses.

[3AlarmLampscooter]

Excellent question!

It's covered (IMO best) in one of the citations on the first paper; a more specialized study of rTMS on the brain that goes into the electrical aspects more heavily, and excitatory versus inhibitory conditions.

Although on the face of it, a temporary inhibitory role of rTMS fits perfectly with reports of the kind of highly focal brain damage frequently seen in true acquired savants.

Transcranial magnetic stimulation: studying the brain-behaviour relationship by induction of 'virtual lesions'.
A Pascual-Leone, D Bartres-Faz, and J P Keenan
Philos Trans R Soc Lond B Biol Sci. 1999 July 29; 354(1387): 1229–1238.

Transcranial magnetic stimulation (TMS) provides a non-invasive method of induction of a focal current in the brain and transient modulation of the function of the targeted cortex. Despite limited understanding about focality and mechanisms of action, TMS provides a unique opportunity of studying brain-behaviour relations in normal humans. TMS can enhance the results of other neuroimaging techniques by establishing the causal link between brain activity and task performance, and by exploring functional brain connectivity.