From treating depression to reducing the effects of Parkinson's disease and awakening patients in a vegetative state, electrical brain stimulation has enormous potential. One new study has focused its efforts on halting cognitive decline by improving memory and learning abilities. An experiment conducted by researchers at Boston University has demonstrated a non-invasive technique that can restore working memory in 70-year-olds to a level that rivals that of people in their 20s.
Many brain stimulation studies use electrodes implanted in specific areas of the brain to deliver electrical impulses. This procedure is called "deep" or "direct" brain stimulation and has its advantages due to the precise positioning of the impact. Nevertheless, the introduction of electrodes into the brain is quite impractical, and simply associated with certain risks of inflammation or infection if all operating standards are not observed.
An alternative is indirect stimulation using a non-invasive (non-surgical) method through electrodes located on the scalp, which allows such manipulations even at home. Rob Reinhart, a neuroscientist at Boston University, decided to use this method in an effort to improve the memory of older people, which, as a rule, weakens with age.
More specifically, his experiments focused entirely on working memory, which kicks in when we remember what we need to pick up at the grocery store, or when we try to find car keys, for example. According to Reinhart, working memory can begin to decline as early as age 30, as different parts of the brain begin to lose their connectivity and become less coherent. When we reach our 60s or 70s, this inconsistency can lead to a marked decline in cognitive function.
The scientist discovered a way to restore broken neural connections. The method is based on two elements of how the brain works. The first is "pairing," when different parts of the brain are activated in sequence, like a finely tuned orchestra. The second is βsynchronization,β where the slower rhythms, known as theta rhythms and associated with the hippocampus, synchronize properly. Both of these functions deteriorate with age and affect memory performance.
For his experiment, Reinhart used a group of young people in their 20s and a group of older people in their 60s and 70s. Each group had to complete a series of specific tasks that involved looking at an image, pausing, looking at a second image, and then recognizing the differences in them from memory.
Not surprisingly, the younger experimental group performed much better than the older group. But then Reinhart applied 25 minutes of gentle cortical stimulation to the elderly, with impulses tuned to each patient's neural circuits according to the area of ββthe cortex responsible for working memory. After that, the groups continued to complete the tasks, and the gap in the accuracy of the task between them disappeared. The effect lasted at least 50 minutes after stimulation. What's more, Reinhart found that he was able to improve memory function even in young adults who performed poorly on tasks.
βWe found that subjects in their 20s who had difficulty completing tasks were also able to benefit from exactly the same stimulation,β says Reinhart. "We were able to improve their working memory even if they weren't in their 60s or 70s."
Reinhart hopes to continue studying how brain stimulation can improve human brain function, especially for those suffering from Alzheimer's disease.
βThis opens up new possibilities for research and treatment,β he says. "And we're very happy about that."
The study was published in the journal Nature Neuroscience.
Source: 3dnews.ru