6 February 2012
What if a drug could improve learning and cognition and had no untoward medical consequences? Wouldn’t it be justified to make it widely available? A group of scientists concluded three years ago that it would be.
No such drug exists, but the question arises anew because of a brain-stimulation technique that appears on paper to fit the bill. The technology, transcranial direct-current stimulation, involves applying weak electrical currents to the scalp through electrodes. It appears to alter brain activity in a long-lasting way that can enhance cognition.
Electrical therapies for the nervous system have a lengthy history. In about 45 AD, the Roman physician Scribonius Largus helped relieve pain by applying electric fish to a patient’s skin. Simple electric stimulation to the scalp appears to have myriad effects, possibly improving motor skills, vision, decision-making, problem-solving attention and mathematical reasoning in healthy individuals.
“Where can I get one?” you might ask. Take your choice. You might buy one for less than $1,000. Or you could make your own: it’s really just a 9-volt battery with a few electrodes, seemingly the perfect high-school science project.
Seems too good to be true. Let’s go now to the ethicists. “Is anything wrong with this picture?” asks an article in press in Current Biology. [Accessible as a PDF through an Oxford University science blog.]
The authors, Roi Cohen Kadosh and a group of scientists and ethicists mostly from Oxford University, note that the electrical brain stimulator really does appear to be pretty safe in healthy adults: there are no reports of seizures, one of the first concerns for any intervention that turns up the volume on neural circuits. In the blog on the University of Oxford site, Cohen Kadosh was quoted: “I can see a time when people plug a simple device into an iPad so that their brain is stimulated when they are doing their homework, learning French or taking up the piano.”
The ethical issue at hand is what happens when you use a technology willy-nilly on an autistic patient, the self-enhancing Wall Street trader or, in particular, healthy children. Direct-current stimulation has, as yet, no training guidelines for health-care workers, let alone e-manuals for self-experimenters or enhancement gurus. “At best, this situation could result in the exploitation of vulnerable patients or parents for financial gain; at worst, it may risk long-term damage to the brain…” the authors wrote. Repeated stimulation to one segment of the brain’s outer layer, the cortex, to enhance number-crunching skills in a child “could even worsen performance and lead to atypical brain development,” relates the Current Biology paper. Enhancing one cognitive function, moreover, could potentially diminish performance of another.
All of these risks are hypothetical, and the researchers acknowledge that a tool that can improve cognitive function and potentially help people with psychiatric disorders or neurological conditions should not be discarded out of hand. At this point, completed studies with adult subjects might provide the basis for formulating guidelines for studies on children. The studies should start small and subjects should be monitored closely for chemical, anatomical and behavioral changes, the Current Biology commentary suggests. The message: wait a bit. It’s not time yet to start a run on 9-volt batteries at Radio Shack.
Source: Roi Cohen Kadosh