Faraday stimulation

The stimulation method could not address the role of the elaboration areas and the study of brain damaged patients or lesion studies of animals is hampered by the lack of temporal resolution. What is needed for another wave of reverse engineering, then, is the ability to stimulate the brain while it is doing something, or to be able to reversibly disrupt its functioning to give the lesion method a temporal dimension. The story of how we are able to achieve both of these takes us back to Faraday.. . . ... 

Michael Faraday reported in 1821 that chlorine addition to alkenes is Stimulated by sunlightand today this is taken to indicate the involvement of a free radical process (equation 26). Free radical chain mechanisms were proposed in 1927 by Berthoud and Beraneck for the isomerization of stilbene catalyzed by Br2 (equation 27), and by Wachholtz for bromine addition to ethyl maleate (equation 28).Later studies showed inhibition of halogen addition by reaction of the intermediate radicals with oxygen, and a free radical chain mechanism for solution and gas phase halogenations as in equation (26) was shown (equation 29). Kinetic and mechanistic... 

The measurement and control of electrostatic charge has been studied more extensively on textile materials than on hair fibers. Methods reported in the literature for static charge measurements include resistivity measurements, Faraday cage [197], dielectric losses, and TSC (thermally stimulated current) spectroscopy [198],... 

Faraday also experimented with the effects of gelatin on the red to blue colour change that was stimulated by the addition of common salt. He reported... 

Interestingly enough, for chemistry, one of the most thorough accounts of static electrical phenomena was that published by Joseph Priestley, The History and Present State of Electricity , London, 1767, in two volumes. It was an article in Encyclopaedia Britannica on the history of electricity by Tytler, copiously illustrated by diagrams of electrostatic machines, based in part on Priestley s volumes, that first stimulated Faraday to construct his first scientific instruments. 

R. M. Wightman When you go to very small electrodes, you indeed have very small currents to measure. It turns out that with modern electronics it is not a particularly difficult problem. Only two precautions were taken first, experiments were done in a Faraday cage, second, all our equipment is home-made so that we can build into it the noise-free level current measurements that I showed you here. It is important to have very low currents, because if we pass high currents we may stimulate the neurons themselves and perturb the system that we are trying to make a measurement on. So the fact that we use very small electrodes has two advantages we have very small currents and we cause minimum perturbation to our tissues. 

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