A team of researchers with the University of Southern California and the Wake Forest School of Medicine has conducted experiments involving implanting electrodes into the brains of human volunteers to see if doing so might improve memory recall. The group gave a presentation at this year's Society for Neuroscience meeting recently outlining the study and what they found.
Prior research has shown that inserting electrodes into the brains of animals can improve memory recall—in this new effort, the researchers discovered the same is true for humans.
To test the idea that sending tiny electrical pulses to parts of the brain involved in memory recall might improve memory, the researchers worked with doctors treating epilepsy patients—each of the patients was scheduled to have a brain electrode implanted as a treatment option. The researchers got 20 of the patients to agree to having another similar electrode implanted into their brains at the same time.
The experiment consisted of two parts. The first was to use the implant to listen for and record electrical activity in the brain while the volunteers engaged in memory exercises. The second part involved mimicking the signals that had been recorded in the first part—sending tiny pulses of electricity to parts of the brain involved in memory retention and retrieval.
The experiments sought to measure two kinds of memory, short-term and working memory. The first, as the name implies, is the ability to remember something that happened recently. Working memory, on the other hand, is used to keep track of things as they are happening.
In looking at all the data from all of the patients, the researchers reported that they found brain stimulation via implants led to an average 15% improvement in short-term memory and a 25% improvement in working memory across all the volunteers—similar to the results found in test animals. They noted that applying random bursts of electrical stimulation, on the other hand, tended to make memory recall worse.
While the experiments were conducted to learn more about memory retention and recall in general, the research is aimed specifically at helping people with memory loss due to ailments such as dementia and Alzheimer's disease.