A certain fictional Dr. Frankenstein thought that putting a bunch of spare human parts together and zapping them with an electrical current would create a splendid new human being. We know how that turned out.
But the idea is still around and some scientists and tinkerers have been using a weak electric current to stimulate their brains, hoping to improve their brainpower in the process.
But a study by researchers at the University of North Carolina School of Medicine finds that the most common form of electric brain stimulation had a statistically significant detrimental effect on IQ scores -- the opposite of the result the do-it-yourselfers were hoping for.
Published in the journal Behavioural Brain Research, the study adds to the increasing amount of literature showing that transcranial direct current stimulation - tDCS - has mixed results when it comes to cognitive enhancement.
"It would be wonderful if we could use tDCS to enhance cognition because then we could potentially use it to treat cognitive impairment in psychiatric illnesses," said Flavio Frohlich, PhD, study senior author. "So, this study is bad news. Yet, the finding makes sense. It means that some of the most sophisticated things the brain can do, in terms of cognition, can't necessarily be altered with just a constant electric current."
Ah, but wait ...
Frohlich, though, said that using less common alternating current stimulation - so-called tACS - could be a better approach, one that he has been investigating. Earlier this year, Frohlich's lab found that tACS significantly boosted creativity, likely because he used it to target the brain's natural electrical alpha oscillations, which have been implicated in creative thought.
With tDCS, scientists don't target these brain waves, which represent neuronal patterns of communication throughout regions of the brain. Instead, they use tDCS to target brain structures, such particular regions of the cortex.
Some researchers have reported good results from tDCS experiments but Frohlich said that some of the studies that have made waves were poorly designed. Some studies were not properly double-blinded or properly placebo controlled. Other studies were very small -- fewer than 10 people.
Jury still out
A recent meta-analysis of a large number of tDCS papers showed that tDCS is far from a magic pill for cognitive enhancement or brain-related health conditions.
"Aside from stimulating the motor cortex, which has very exciting implications for stroke rehabilitation, I think the jury is still out on tDCS," said Frohlich, who is a member of the UNC Neuroscience Center.
Frohlich stressed that the scientific community should be careful not to create simplistic storylines about tDCS being a 'magic pill' for many brain-related conditions. "There could be dangerous consequences, especially if tDCS is used daily," he said. "Ours was an acute study. We don't know what the long-term effects are. There is so much more we need to understand before tDCS is ready for home use without medical supervision."