Two complementary studies recently found that noninvasive and extremely mild brain stimulation could be used to improve episodic and working memory in older adults. We can make these 60 and 70-year-olds look strikingly like our 20-year-old participants," researcher Robert Reinhart [said]. The first study used a technique called transcranial magnetic stimulation (TMS) to induce mild neural firing in the brain. The research team stimulated the participants' brains for half an hour a day for five days. They then measured the adults' memory ability 24 hours after the final day of stimulation and found their recall ability on a memory test had improved 31 per cent. The second study, led by Robert Reinhart from ... Boston University, used a different technology, and stimulated different regions of the brain. Using electroencephalography, or EEG, which records the electrical activity of the brain, Reinhart found evidence that older adults' brain waves were out-of-sync in critical brain regions used by working memory or short-term memory. Reinhart then tried to ameliorate the problem by using a precise and customizable electrical stimulation technology called "high definition transcranial alternating current stimulation," or HD-tACS for short. The team applied current for 25 minutes to 42 older participants' brains, and saw improvements during this time on a memory test that they did before they received stimulation. As in Voss' study, the subjects' performance increased to the point that it was equal to that of 20-year-olds.