X-Message-Number: 24964
Date: Mon, 1 Nov 2004 20:06:51 -0800
Subject: Electric currents boost brain power 
From: Kennita Watson <>

The news on brains isn't all bad today (kids, don't try this
at home!).

Published online: 26 October 2004; | doi:10.1038/news041025-9
Electric currents boost brain power
Jim Giles
Just 20 minutes with a battery is enough to ramp up verbal prowess.

Connecting a battery across the front of the head can boost verbal 
skills, says a team from the US National Institutes of Health.

A current of two thousandths of an ampere (a fraction of that needed to 
power a digital watch) applied for 20 minutes is enough to produce a 
significant improvement, according to data presented this week at the 
annual meeting of the Society for Neuroscience, held in San Diego. And 
apart from an itchy sensation around the scalp electrode, subjects in 
the trials reported no side-effects.

Meenakshi Iyer of the National Institute of Neurological Disorders and 
Stroke in Bethesda, Maryland, ran the current through 103 initially 
nervous volunteers. "I had to explain it in detail to the first one or 
two subjects," she says. But once she had convinced them that the 
current was harmless, Iyer says, recruitment was not a problem.

The volunteers were asked to name as many words as possible beginning 
with a particular letter. Given around 90 seconds, most people get 
around 20 words. But when Iyer administered the current, her volunteers 
were able to name around 20% more words than controls, who had the 
electrodes attached but no current delivered. A smaller current of one 
thousandth of an amp had no effect.

Trigger happy

Iyer says more work needs to be done to explain the effect, but she 
speculates that the current changes the electrical properties of brain 
cells in the prefrontal cortex, the brain region through which it 
passes. She believes that the cells fire off signals more easily after 
the current has gone by. That would make the brain area, a region 
involved in word generation, generally more active, she suggests.

Iyer's group, which is led by Eric Wassermann, was prompted to run the 
tests after considering problems facing researchers who were studying 
the effect of magnetic fields on the brain. Some neuroscientists hope 
that magnetic fields could have a therapeutic effect, perhaps by 
boosting activity in areas of the brain that have suffered cell loss 
owing to dementia. But magnetic fields can cause seizures and also 
require bulky equipment to generate them.

Iyer hopes that low electric currents will offer a safer and more 
portable alternative. After running further safety tests, she plans to 
test the effect of the current on patients with frontal temporal 
dementia, a brain disease that causes speech problems. "This won't be a 
cure," Iyer cautions. "But it could be used in addition to drugs."

The idea of using electrical current to boost brain activity dates back 
to experiments on animals in the 1950s. The early work showed some 
potential, but fell from favour because of a perceived link to 
electroconvulsive therapy, a controversial technique in which patients 
with depression are treated by having short but intense pulses of 
electricity applied to the brain.

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