Brain zaps boost memory

Today, another "No way, really?!" study gets added to the list. Scientists have boosted memory skills in healthy volunteers by zapping their brains with weak electromagnetic pulses, National Geographic reports. The memory gain was fairly small - not enough for most of us to notice in our everyday lives, the researchers say. But even a modest improvement could be meaningful for people with conditions that damage memory, such as a stroke, heart attack, traumatic brain injury or Alzheimer's disease. "This memory network that we targeted has been shown to be impaired in a variety of disorders," says lead investigator Joel Voss, a neuroscientist at Northwestern University. If people with these disorders show similar memory gains in future experiments, the technology could be easily translated into the clinic, Voss adds. "It's definitely the kind of thing that could be turned into an intervention that could be implemented in the hospital, and eventually maybe a doctor's office." The technology, called transcranial magnetic stimulation or TMS, involves a wand emitting a changing magnetic field. When pressed against the skull, it induces changes in the electrical patterns of nearby neurons. In the new study, published today in Science, the researchers used TMS to stimulate a spot in the outer layers of the brain called the lateral parietal cortex. Activity in this region is known to be strongly synchronized with the hippocampus, a region crucial for memory. (The hippocampus itself is too deep to be directly affected by TMS.) To the person being stimulated, "it feels like somebody flicking the outside of your head with their finger", says Voss, who says he has experienced it hundreds of times. "You can't feel anything in terms of your thinking," he says. "You don't feel souped up afterwards." The researchers stimulated this area in 16 adult volunteers for five consecutive days. Each stimulation session lasted 20 minutes, during which volunteers would feel 2 seconds of pulsing, then 28 seconds of nothing, then 2 seconds of pulsing, and so on. Brain scans of the volunteers before and after their week of stimulation showed that the treatment significantly increased connectivity between the hippocampus and four other areas, including the lateral parietal cortex. So it seems that stimulating one part of the hippocampal memory network (the lateral parietal cortex) led to more robust connections in other parts of the same network. Details at