Groundbreaking new study finds significant links between memory and sleep

"MRI scans showing locations of medial-temporal electrodes in a representative patient." (Northwestern Now) Image source: Department of Neurological Surgery, The University of Chicago

Neuroscientists from Northwestern University and clinicians from the University of Chicago Epilepsy Center recently published a study that explored the relationship between memory and sleep.

Researchers studied brain electrical activity in five of the center’s patients in response to sounds administered by the research team as part of a learning exercise. Participates in the study had electrode probes implanted into the brain for the purpose of investigating potential treatments for their seizure disorders.

The next morning, researchers found that participants significantly improved their performance in a recall test after the scientists measured the electrical activity in their brains. The EEG scans were critical in helping the researchers understand how memory storage works by providing visual data identifying the areas of the brain engaged in the process of overnight memory storage.

Ken Paller, the director of the Cognitive Neuroscience Program at Northwestern, was the senior researcher on the study.

“At times, remembering and forgetting seems random,” said Paller. “We can remember irrelevant details while forgetting what we most want to remember. The new answer to this long-standing mystery, highlighted by this research, is that memories are revisited when we sleep, even though we wake up not knowing it happened,” Paller said.

Paller is a professor of psychology and the James Padilla Chair in Arts and Science at Northwestern’s Weinberg College of Arts and Sciences. His research interests include human memory, perception, cognition, and the
biological bases of other mental phenomena.

Learn more in Northwestern Now’s article, “Study looks inside the brain during sleep to show how memory is stored.”