Eurekalert reports on research by A. Pogosyan and others (here) that gives evidence that brain waves can cause effects in brain cells.
“At last we have some direct experimental proof that brain waves influence behavior in humans, in this case how fast a movement is performed. The implication is that it is not just how active brain cells are that is important, but also how they couple their activity into patterns like beta activity… The electrical current used increased normal beta activity, a wave that earlier studies linked to sustained muscle activities, such as holding a book. Beta activity drops before people make a move.
Unlike most previous work, which used constant brain stimulation, the new study employed an oscillating current, more like that underlying normal brain activity. As a result, people’s fastest times on the computer task were 10 percent slower… researchers were surprised that the electrical currents used in the study—which were very small and imperceptible to the participants—could have such a measurable effect… The current findings provide the first interventional evidence of a causal link between increased beta synchrony and the slowing of voluntary movement in otherwise healthy individuals, the researchers report, noting that earlier studies have shown altered brain waves to influence memory. ”
This will certainly complicate how we view feedback loops in the brain. Brain waves might not just be indicators of what is be going on, but may be players in their own right.