Transcranial magnetic stimulation (TMS) is a fascinating field of study in which it is clearly possible to affect the brain, but researchers are still in the comparatively early stages of finding out how to reliably produce and measure useful end results. The research noted here is an example of one of the more positive findings, a way to enhance memory function. It doesn't address underlying causes of dysfunction in aging, unfortunately, rather being a possible methodology to compensate somewhat for losses. This isn't the preferred direction for medicine if we seek true prevention and cure of age-related loss of function, but as for many such things, one has to ask "why not see whether or not this can be applied all the time, for everyone?"
In the past, TMS has been used in a limited way to temporarily change brain function to improve performance during a test, for example, making someone push a button slightly faster while the brain is being stimulated. The study shows that TMS can be used to improve memory for events at least 24 hours after the stimulation is given.
It isn't possible to directly stimulate the hippocampus with TMS because it's too deep in the brain for the magnetic fields to penetrate. So, using an MRI scan, [researchers] identified a superficial brain region a mere centimeter from the surface of the skull with high connectivity to the hippocampus. [They] wanted to see if directing the stimulation to this spot would in turn stimulate the hippocampus. It did. When TMS was used to stimulate this spot, regions in the brain involved with the hippocampus became more synchronized with each other, as indicated by data taken while subjects were inside an MRI machine, which records the blood flow in the brain as an indirect measure of neuronal activity. The more those regions worked together due to the stimulation, the better people were able to learn new information.
Scientists recruited 16 healthy adults ages 21 to 40. Each had a detailed anatomical image taken of his or her brain as well as 10 minutes of recording brain activity while lying quietly inside an MRI scanner. Doing this allowed the researchers to identify each person's network of brain structures that are involved in memory and well connected to the hippocampus. The structures are slightly different in each person and may vary in location by as much as a few centimeters. Each participant then underwent a memory test, consisting of a set of arbitrary associations between faces and words that they were asked to learn and remember. After establishing their baseline ability to perform on this memory task, participants received brain stimulation 20 minutes a day for five consecutive days. Then, at least 24 hours after the final stimulation, they were tested again. Both groups performed better on memory tests as a result of the brain stimulation. It took three days of stimulation before they improved.
In an upcoming trial, [researchers] will study the electrical stimulation's effect on people with early-stage memory loss, [but] cautioned that years of research are needed to determine whether this approach is safe or effective for patients with Alzheimer's disease or similar disorders of memory.