DARIEN, Ill. — People usually start forgetting their dreams moments after waking up. Some of the more bizarre dreams however, full of people we haven’t seen in years or seemingly nonsensical events, can stick with us much longer. Academics and philosophers have debated the true purpose and meaning of dreams for centuries. Now, a new study is offering up some compelling evidence that dreams are a way for our minds to look back on the past and predict the future simultaneously.
According to the findings, dreams result from a process that combines various memories from past experiences while anticipating how future events may unfold.
“Humans have struggled to understand the meaning of dreams for millennia,” says principal investigator Erin Wamsley, an associate professor in the department of psychology and program in neuroscience at Furman University, in a media release. “We present new evidence that dreams reflect a memory-processing function. Although it has long been known that dreams incorporate fragments of past experience, our data suggest that dreams also anticipate probable future events.”
Most of our dreams come from old memories
A total of 48 students took part in this project. Each participant agreed to spend one night in the researchers’ lab for overnight evaluation using a sleep study technique called polysomnography. It wasn’t exactly a restful night: study authors woke the students up 13 times throughout the evening to report on their experiences during sleep onset, REM sleep, and non-REM sleep. In the morning, everyone was asked to connect their dreams from the previous night to any real-life waking memories from the past. In total, the team analyzed 481 dream/memory reports.
Researchers traced over half of the dreams (53.5%) to real-life memories. Just under 50 percent of the reports with a memory source had a connection to multiple past experiences. Meanwhile, 25.7 percent of examined dreams appeared to have a connection to a specific impending event in a student’s life. More than a third (37.4%) of the dreams focusing on the future also had a link to one or more specific memories from the dreamer’s past.
“This is a new description of how dreams draw simultaneously from multiple waking-life sources, utilizing fragments of past experience to construct novel scenarios anticipating future events,” Wamsley adds.
Notably, dreams looking ahead to future events tended to occur more often later in the evening. Prof. Wamsley theorizes this tendency may be due to the “temporal proximity” of upcoming events — or when events occur relatively close to each other in time.
Dreams focusing on the future are rarely realistic or accurate, but the very process of using memories to help look ahead in time “may nonetheless serve an adaptive function,” study authors conclude.
The study appears in the journal Sleep and the team is presenting their findings at the Virtual SLEEP 2021 meeting.