The Yale School of Medicine is researching the application of transcranial magnetic stimulation (TMS) to silence the voices in the heads of people with schizophrenia. TMS is the non-invasive use of rapidly changing magnetic fields to induce specific electromagnetic fields in the brain. Stimuli are applied to an area of the brain several times per second for several seconds. The quantity, strength, duration and interval between stimuli are refered to as the stimulation parameters. While electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) allow researcher to see which parts of the brain activate when a subject performs a certain task, they can’t prove that those parts are in fact used for the task. But if they can suppress the activity through TMS stimulation, then the part is probably used in the performance. So, by holding magnets over parts of the skull for a few minutes a day, it’s possible to alter the very biochemistry of the brain, stimulating or suppressing different regions, with effects that can last beyond the duration of the application. Yale psychiatrist Ralph Hoffman MD hopes to use this technology to treat tha auditory hallucinations of schizoprenics. By focusing on the Wernicke’s region in the left temporal lobe and another region on the opposite side of the brain (parts used in perceiving words spoken by others), he was able to reduce these hallucinations.

Auditory hallucinations are not the only applications for TMS. Tony Ro at the Rice University, TX, applied TMS to the visual cortex (in the back of the brain, used for seeing) to interrupt the normal visual pathway, thereby enducing the peculiar phenomenon of zombie vision. Better known as ‘blindsight’, it is the condition found in some patients with brain damage who report not seeing something but correctly identify the shape and location when forced to guess. In Ro’s experiments, subjects were shown vertical and horizontal lines on a computer screen, but because the pathways were jammed while under TMS they reported seeing nothing. Still, when asked to guess they gave the right answer 75% of the time. In a similar experiment with red and green dots, their accuracy rose to 81%. "This high degree of accuracy for both the directional orientation and color tasks was significantly above chance," says Ro. "It’s clear that detailed visual information was still being processed unconsciously."

TMS can also enhance areas of the brain, making people exhibit dazzling latent intelligence, sparks of genius one sometimes finds in autistic people. Alan Snyder of the University of Sydney conducted many experiments on university students in which he used TMS to stimulate the frontal lobe and measured subjects’ ability to draw, proofreed and do math. After repeated controlled experiments he found that 40% of the volunteers exhibited extrodinarily inhanced abilities: drawing better than they thought they ever could, catching mistakes they missed before TMS, and solving math problems faster. This has led Snyder to believe that autistic thought is not a biological fluke like some supposed, but rather a variation on thinking we may all be capable of.

Clearly, transcranial magnetic stimulation has many uses. It can strip us of our senses, rendering us unable to perform even the most basic tasks, or it can open our minds, stimulating hidden talents we never knew we had. TMS machines still run for $25,000-50,000 and are not sold to the general public, limiting their use to hospitals and universities. Nor are there any schematics for how to make one on the internet, unlike the make-your-own EEG. So, if you want to get hooked-up, your best bet is probably volunteering for neurology/cognitive science research.

Yale expands research using magnetic stimulation for schizophrenia, EurekAlert.org
Out of sight, out of mind? EurekAlert.org
Savant for a day, NYTimes.com
Transcranial magnetic stimulation, Wiki