Science & Tech
Glimpse into how mind may affect healing

Illustration by Liz Zonarich/Harvard Staff

Christy DeSmith

Harvard Staff Writer

March 1, 2024 4 min read

Study finds bruising fades faster in patients who are led to believe more time has passed than actually has

Time, it is said, heals all wounds. But what if a patient is led to believe even more time has passed than actually has?

According to a new study by Harvard researchers Peter Aungle and Ellen Langer, an individual’s perception of how much time has elapsed substantially impacts the speed at which minor bruising fades. Their study, recently published in Nature Scientific Reports, is the first to demonstrate this psychological effect on the physical healing process.

Aungle, the paper’s lead author and a psychology Ph.D. candidate in the Kenneth C. Griffin Graduate School of Arts and Sciences, designed the study with inspiration from a variety of sources. First and foremost was his primary adviser Langer, a veteran psychology professor and expert on mind-body unity.

Langer’s international bestseller “Mindfulness” (1989) as well as her 1977 paper, concerning the health of nursing-home residents assigned to care for houseplants, are well-known. Another classic is her 1980s study on groups of older men who showed physical improvement after spending five days at a remote monastery outfitted to evoke their younger years.

Peter Aungle.

Kris Snibbe/Harvard Staff Photographer

“I don’t think there’s anyone like Ellen Langer,” Aungle said in a recent interview, gesturing to one of her abstract paintings displayed on the wall behind him. “She’s just a creative person in general.”

Aungle also framed his research based on a set of previous studies concerning the perception of elapsed time, both conducted by post-graduate researchers in Langer’s lab. The first, published in 2016, demonstrated that blood glucose levels for Type 2 diabetics fluctuated according to perceived time rather than real time.

The other study, from the year 2020, looked at how performance on cognitive tests was affected by how much sleep volunteers thought they had the night before. Reaction times proved sharp after just five hours of shut eye when study participants believed they logged a full eight hours. At the same time, slower reactions were recorded by those who slept eight hours but thought it was five.

Mind over matter?

Researchers manipulated perceived time in the lab with a simple timer over 28 minutes

Study participants who thought 14 minutes had passed had a healing rate of 6.17.

Those who thought 56 minutes had lapsed had a mean healing rating of 7.5.

Illustrations by Liz Zonarich/Harvard Staff

With Langer’s guidance, Aungle hypothesized that physical wounds would heal faster when time was manipulated to feel longer. Likewise, he thought speeding up the clock would produce less healing. To test these ideas, he struck upon the idea of using a centuries-old blood-flow therapy that left volunteers with minor bruising on the forearm.

“It came up in a lab meeting,” Aungle recalled. “A student who played hockey had some experience with cupping.”

Perceived time was then manipulated with what Aungle called “a very simple timer with two little digits on a browser screen.” The actual elapsed time was 28 minutes. The perceived time was halved to 14 minutes in one session and doubled to 56 in another. A control session tested physical healing with the timer accurately set. Each experimental condition was completed by all 33 of the study’s participants over about two weeks.

Finally, 25 impartial observers were recruited to compare before-and-after photos of the volunteers’ cupping bruises. Their assignment was to rate healing on a 10-point scale (with 10 being “completely healed”).

Higher rates of healing were recorded in the sessions where volunteers believed more time had passed. Healing rates had a mean rating of 7.5 for participants who thought 56 minutes had passed. Compare that with a mean of 6.17 in the 14-minute condition and 6.43 in the control.

As Aungle and Langer summarize in the paper: “Just over a third of participants had almost completely healed in the 56-min condition — more than double the percentage of participants who had almost completely healed in the 14-min condition.”

Psychological influences on human health have been traditionally understood in terms of emotion (say, ending a stressful workweek felled by a cold) or influences on behavior (eating fresh vegetables, hitting up that yoga class). As Aungle put it, his findings suggest that even “abstract, conceptual beliefs can meaningfully shape how our bodies work.”

Planning is already underway for a field study where the psychological experience of time can be manipulated for those recovering from far more serious wounds post-surgery.