Deep, uninterrupted sleep can boost memory, according to a new study. Photo by StockSnap / Pixabay
Jan. 12 (UPI) – Better memory of people’s names and faces may be a matter of improved sleep, according to a study published Wednesday by the journal NPJ: Science of Learning.
Study participants’ name recall improved when memories of newly learned face name associations were reactivated with previously recorded audio while sleeping, with the key being uninterrupted deep sleep, the researchers said.
The data showed that those with uninterrupted sleep who heard recordings of people’s names remembered just over 1.5 more names on average when shown pictures of the people than those who did not experience deep sleep when they heard the recordings.
In study participants with insomnia from electroencephalogram readings, memory reactivation during sleep did not help and may have had a negative effect, they said.
The EEG records electrical activity in the brain through electrodes attached to the scalp, the researchers said.
“We already know that some sleep disorders, like apnea, can affect memory,” study co-author Nathan Whitmore said in a press release.
“Our research suggests a possible explanation for this: Frequent sleep interruptions at night could impair memory,” said Whitmore, a graduate student at Northwestern University in Evanston, Illinois.
Previous studies have shown that more and better sleep can improve memory and brain health, and that light sleep can impair cognitive function.
For this study, Whitmore and his colleagues asked 24 participants, ages 18 to 31, to memorize the faces and names of 40 students from a hypothetical Latin American history class and another 40 from a Japanese history class.
When each face was shown again, they were asked to repeat the associated name, the researchers said.
After the memory exercise, participants took a nap while the researchers carefully monitored brain activity using EEG.
When participants entered a deep sleep state, according to the researchers, some of the names were played softly on a speaker with music associated with one of the classes.
When they woke up, they were retested for their ability to remember the name that went with each face, the researchers said.
Participants, on average, remembered 74 of the 80 names before sleep and 75 of the 80 names after sleep, the data showed.
However, those who experienced deep sleep while playing the name recordings remembered about 1.5 more names on average than those who slept less well, the researchers said.
In future studies, the researchers hope to assess whether a sleep disorder always affects brain function and whether it can be used to weaken unwanted memories like abuse or trauma, they said.
“It’s a new and exciting finding about sleep because it tells us that the way information is reactivated during sleep to improve memory retention is linked to quality sleep,” said Whitmore.