During the study, the research team delivered neurostimulation to study participants during visual recognition memory tasks. (Credit: Wake Forest Baptist)

A team of scientists has demonstrated the first successful use of a neural prosthetic device to recall specific memories. This groundbreaking research was derived from research that showed the successful implementation of a prosthetic system that uses a person’s own memory patterns to facilitate the brain’s ability to encode and recall memory.

In the previous study, the team’s electronic prosthetic system was based on a multi-input multi-output (MIMO) nonlinear mathematical model, and the researchers influenced the firing patterns of multiple neurons in the hippocampus, a part of the brain involved in making new memories.

In this study, researchers built a new model of processes that assists the hippocampus in helping people remember specific information. When the brain tries to store or recall information such as, “I turned off the stove” or “Where did I put my car keys?” groups of cells work together in neural ensembles that activate so that the information is stored or recalled. Using recordings of the activity of these brain cells, the researchers created a memory decoding model (MDM), which let them decode what neural activity is used to store different pieces of specific information. The neural activity decoded by the MDM was then used to create a pattern, or code, which was used to apply neurostimulation to the hippocampus when the brain was trying to store that information.

The team delivered MDM electrical stimulation during visual recognition memory tasks to see if the stimulation could help people remember images better. They found that when they used this electrical stimulation, there were significant changes in how well people remembered things. In about 22 percent of cases, there was a noticeable difference in performance.

When they looked specifically at participants with impaired memory function, who were given the stimulation on both sides of their brain, almost 40 percent of them showed significant changes in memory performance.

The team’s goal is to create an intervention that can restore memory function that’s lost because of Alzheimer’s disease, stroke or head injury.