How Dreams Might Prepare You for What’s Next

June 16, 2021 — What you experience in your dreams might feel random and disjointed, but that chaos during sleep might serve a function, according to Erin Wamsley, PhD, an associate professor of psychology and neuroscience at Furman University in Greenville, SC. In fact, evidence uncovered by Wamsley and her team suggests that dreams can prepare the mind for future situations it will encounter.

Previous research and anecdotal evidence have shown that dreams use fragments of past experiences, Wamsley explains. While studying dreams, her team found that the mind is using select fragments of past experiences to prepare for a known upcoming event.

“This is new evidence that dreams reflect a memory-processing function,” says Wamsley, who presented the work at the virtual SLEEP 2021 conference.

Some high performers already use past experiences to excel in future events. For instance, Michael Phelps, the most decorated Olympic swimmer, with 28 medals, would “mentally rehearse” his swims for up to 2 hours a day, according to his coach, Bob Bowman.

Using sleep to strengthen this process is an exciting prospect that scientists have been eager to figure out, says Allison Brager, PhD, director of human performance at the U.S. Army Warrior Fitness Training Center. Deep, rapid-eye-movement, or REM, sleep can lead to improved learning and memory, she says. “So, hypothetically, better dreams mean better sleep, and that equals better performance.”

For their research, Wamsley’s team hooked 48 students up to a polysomnography machine to measure sleep cycles and how often they were in a deep REM sleep. The students who took part in the study spent the night in a sleep lab.

The students were woken up multiple times during the night and asked to report what they were dreaming about.

In the morning, they were given their reports and asked to identify familiar features or potential sources for particular dreams. More than half the dreams were tied to a memory the students recalled. One-quarter of the dreams were related to specific upcoming events the students reported. And about 40% of the dreams with a future event in them also included memories of past experiences. This was more common the longer the students dreamed, the scientists explain.