Recording memory patterns and feeding back can boost memory by up to 37% in Alzheimers patients

Scientists at Wake Forest Baptist Medical Center and the University of Southern California (USC) have demonstrated 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.

Advanced Lifelogging seems needed to support memory boosting. Most Healthy early lifelogging adopters found it not useful

For a real-world version of this memory aid, it seems like a constant life logging and recording device that records video and brain scans. This would need to be combined with an AI interface to determine which brain scan memories to reinforce for each situation.

Early adopters of lifelogging generally gave up on the practice in 2016. Most found it was not useful.

Reinforcing memory

In the pilot study, published in today’s Journal of Neural Engineering, participants’ short-term memory performance showed a 35 to 37 percent improvement over baseline measurements. The research was funded by the U.S. Defense Advanced Research Projects Agency (DARPA).

“This is the first time scientists have been able to identify a patient’s own brain cell code or pattern for memory and, in essence, ‘write in’ that code to make existing memory work better, an important first step in potentially restoring memory loss,” said the study’s lead author Robert Hampson, Ph.D., professor of physiology/pharmacology and neurology at Wake Forest Baptist.

The study focused on improving episodic memory, which is the most common type of memory loss in people with Alzheimer’s disease, stroke and head injury. Episodic memory is information that is new and useful for a short period of time, such as where you parked your car on any given day. Reference memory is information that is held and used for a long time, such as what is learned in school.

Journal of Neural Engineering – Developing a hippocampal neural prosthetic to facilitate human memory encoding and recall

Researchers demonstrated the first successful implementation in humans of a proof-of-concept system for restoring and improving memory function via facilitation of memory encoding using the patient’s own hippocampal spatiotemporal neural codes for memory. Memory in humans is subject to disruption by drugs, disease and brain injury, yet previous attempts to restore or rescue memory function in humans typically involved only nonspecific, modulation of brain areas and neural systems related to memory retrieval.

Approach. They constructed a model of processes by which the hippocampus encodes memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of short-term memory. A nonlinear multi-input, multi-output (MIMO) model of hippocampal CA3 and CA1 neural firing is computed that predicts activation patterns of CA1 neurons during the encoding (sample) phase of a delayed match-to-sample (DMS) human short-term memory task.

Main results. MIMO model-derived electrical stimulation delivered to the same CA1 locations during the sample phase of DMS trials facilitated short-term/working memory by 37% during the task. Longer term memory retention was also tested in the same human subjects with a delayed recognition (DR) task that utilized images from the DMS task, along with images that were not from the task. Across the subjects, the stimulated trials exhibited significant improvement (35%) in both short-term and long-term retention of visual information.

Significance. These results demonstrate the facilitation of memory encoding which is an important feature for the construction of an implantable neural prosthetic to improve human memory.

Statement from the researcher

“We were looking to see if it was possible to use the patient’s own code for memory; to strengthen that and feed it back in so that we could essentially restore the ability to encode and retrieve memory. Our study was designed to work with patients that already had electrodes in their hippocampus. That patient population is epilepsy patients who have seizures that will require some form of surgery to correct their seizures. These patients have electrodes placed into areas of the brain, including the hippocampus, and they stay there for about two weeks. While the patients are in the hospital… when they’re not doing the studies necessary for their medical care, we can go in and we can test. We have the patient play a computer game that involves memory, and we record the activity of the brain cells, the neurons, in hippocampus.

“So what we found is that when we tested patients by stimulating their hippocampus with a pattern that was derived from their own neural activity in hippocampus, we were able to improve their short-term memory by quite a bit. We had two tests: one was a very short-term memory that lasted about 120 seconds—two minutes—and we found that we could improve their performance on the memory test at that range about 37%. We had a second test, that worked very similar, in which we were able to test memory that was lasting more than an hour—up to 75 min—and we found in that case we were able to improve memory performance by 35%. So under both conditions we were able to see quite a substantial improvement in memory.

“Our goal is to restore memory, and right now we’re working with patients that already have electrodes, and what we would like to do is to be able to help people who are not necessarily in that same patient population we’re working with right now. That is going to require some decisions by the doctors, by the patients, and by the researchers as to when we put electrodes in and who we’re going to help; but our target is to help people who have had a traumatic brain injury, who have had stroke, people who have memory loss due to aging Alzheimer’s or any number of other diseases that can affect the memory.

“In one sense we were not surprised to find that this worked. We had a long history of animal studies in which we were testing this concept in other species—in animals in the laboratory—and we were having success. What surprised us was how successful it was. Thirty-five percent improvement in memory is huge; and the results that we have compared to some other techniques indicate this is a very successful attempt to restore memory.