Researchers show brain stimulation restores memory during lapses

April 20, 2017, University of Pennsylvania
Credit: Human Brain Project

A team of neuroscientists at the University of Pennsylvania has shown for the first time that electrical stimulation delivered when memory is predicted to fail can improve memory function in the human brain. That same stimulation generally becomes disruptive when electrical pulses arrive during periods of effective memory function.

The research team included Michael Kahana, professor of psychology and principal investigator of the Defense Advanced Research Projects Agency's Restoring Active Memory program; Youssef Ezzyat, a senior data scientist in Kahana's lab; and Daniel Rizzuto, director of cognitive neuromodulation at Penn. They published their findings in the journal Current Biology.

This work is an important step toward the long-term goal of Restoring Active Memory, a four-year Department of Defense project aimed at developing next-generation technologies that improve in people who suffer from loss. It illustrates an important link between appropriately timed deep- stimulation and its potential therapeutic benefits.

To get to this point, the Penn team first had to understand and decode signaling patterns that correspond to highs and lows of memory .

"By applying machine-learning methods to electrical signals measured at widespread locations throughout the ," said Ezzyat, lead paper author, "we are able to identify neural activity that indicates when a given patient will have lapses of memory encoding."

Using this model, Kahana's team examined how the effects of stimulation differ during poor versus effective memory function. The study involved neurosurgical patients receiving treatment for epilepsy at the Hospital of the University of Pennsylvania, the Thomas Jefferson University Hospital, the Dartmouth-Hitchcock Medical Center, the Emory University Hospital, the University of Texas Southwestern, the Mayo Clinic, Columbia University, the National Institutes of Health Clinical Center and the University of Washington. Participants were asked to study and recall lists of common words while receiving safe levels of .

During this process, the Penn team recorded electrical activity from electrodes implanted in the patients' brains as part of routine clinical care. These recordings identified the biomarkers of successful memory function, activity patterns that occur when the brain effectively creates new memories.

"We found that, when arrives during periods of effective memory, memory worsens," Kahana said. "But when the electrical stimulation arrives at times of poor function, memory is significantly improved."

Kahana likens it to traffic patterns in the brain: stimulating the brain during a backup restores the normal flow of traffic.

Gaining insight into this process could improve the lives of many types of patients, particularly those with traumatic brain injury or neurological diseases, such Alzheimer's. "Technology based on this type of stimulation," Rizzuto said, "could produce meaningful gains in memory performance, but more work is needed to move from proof-of-concept to an actual therapeutic platform."

This past November, the RAM team publicly released an extensive intracranial brain recording and stimulation dataset that included more than 1,000 hours of data from 150 patients performing memory tasks.

Explore further: Brain stimulation used like a scalpel to improve memory

Related Stories

Brain stimulation used like a scalpel to improve memory

January 19, 2017
Northwestern Medicine scientists showed for the first time that non-invasive brain stimulation can be used like a scalpel, rather than like a hammer, to cause a specific improvement in precise memory.

Buzzing the brain with electricity can boost working memory

March 14, 2017
Scientists have uncovered a method for improving short-term working memory, by stimulating the brain with electricity to synchronise brain waves.

Deep brain stimulation may not boost memory

December 7, 2016
Deep brain stimulation (DBS) of areas in the brain known to be involved in making memories does not improve memory performance, according to a study by Columbia University researchers published December 7 in Neuron. The study ...

Improving memory with magnets

March 27, 2017
The ability to remember sounds, and manipulate them in our minds, is incredibly important to our daily lives—without it we would not be able to understand a sentence, or do simple arithmetic. New research is shedding light ...

Sound waves boost older adult' memory, deep sleep

March 8, 2017
Gentle sound stimulation—such as the rush of a waterfall—synchronized to the rhythm of brain waves significantly enhanced deep sleep in older adults and improved their ability to recall words, reports a new Northwestern ...

Mechanism behind the activation of dormant memory cells discovered

February 20, 2014
The electrical stimulation of the hippocampus in in-vivo experiments activates precisely the same receptor complexes as learning or memory recall. This has been discovered for the first time and the finding has now been published ...

Recommended for you

Researchers target immune cells to slow progression of Amyotrophic Lateral Sclerosis

March 22, 2018
New research into Amyotrophic Lateral Sclerosis (ALS) - also known as motor neuron disease - shows that specific immune cells may help slow progression of the disease, an important step towards developing new therapies to ...

Focus on early stage of illness may be key to treating ALS, study suggests

March 22, 2018
A new kind of genetically engineered mouse and an innovation in how to monitor those mice during research have shed new light on the early development of an inherited form of amyotrophic lateral sclerosis (ALS).

Flow of spinal fluid disrupted in inherited developmental disorder

March 22, 2018
Scientists have pinpointed the mechanism behind hydrocephalus, an accumulation of cerebrospinal fluid around the brain, in an inherited developmental disorder called Noonan syndrome.

Obesity trigger identified within the human gut

March 22, 2018
The key chemical for happiness and sadness, serotonin, is also a force in our body's weight gain and calorie control, and scientists say more research could reduce obesity rates.

New wearable brain scanner allows patients to move freely for the first time

March 21, 2018
A new generation of brain scanner, that can be worn like a helmet allowing patients to move naturally whilst being scanned, has been developed by researchers at the Sir Peter Mansfield Imaging Centre, University of Nottingham ...

International team confirms new genetic mutation link to amyotrophic lateral sclerosis

March 21, 2018
Kinesin family member 5A (KIF5A), a gene previously linked to two rare neurodegenerative disorders, has been definitively connected to amyotrophic lateral sclerosis (ALS) by an international team from several of the world's ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.