A day on holiday can feel like it lasts longer than a normal day because it is a new and interesting experience, Martin Wiener, the study’s co-author, suggests. Photograph: © Peter Lourenco/Getty Images
If every day appears to go in a blur, try seeking out new and interesting experiences, researchers have suggested, after finding memorable images appear to dilate time.
Researchers have previously found louder experiences seem to last longer, while focusing on the clock also makes time dilate, or drag.
Now researchers have discovered the more memorable an image, the more likely a person is to think they have been looking at it for longer than they actually have. Such images were also easier for participants to recall the next day.
Prof Martin Wiener, co-author of the study who is based at George Mason University in the US, said the findings could help develop improve artificial intelligence that interacts with humans, while they also offer opportunities to tweak our perceptions, given research has previously shown non-invasive brain stimulation can be used to lengthen a perceived interval.
“One idea could be, well, if we can lengthen a perceived interval while showing an image to a person, that image may be remembered better 24 hours later,” Wiener said.
Writing in the journal Nature Human Behaviour, Wiener and colleagues described how they showed scenes of six different sizes and six different levels of clutter to participants for between 300 and 900 ms, and asked them to indicate if they thought the duration was long or short.
The results from two groups, totalling about 100 people, revealed participants were more likely to think they had been looking at small, highly cluttered scenes – such a crammed pantry – for a shorter duration than was the case, whereas the reverse occurred when people viewed large scenes with little clutter, such as the interior of an aircraft hangar.
The team also carried out experiments involving 69 participants that found images known from previous work to be more memorable were more likely to be judged as having been shown for longer than was the case.
Crucially, the effect seemed to go both ways.
“We also found that the longer the perceived subjective duration of an image, the more likely you were to remember it the next day,” said Wiener.
When the team carried out an analysis using deep learning models of the visual system, they discovered more memorable images were processed faster. What’s more, the processing speed for an image was correlated with how long participants thought they had been looking at it.
“Images may be more memorable because they are processed faster and more efficiently in the visual system, and that drives the perception of time,” said Wiener.
The team suggest time dilation might serve a purpose, enabling us to gather information about the world around us.
“When we see things that are more important or relevant, like things that are more memorable, we dilate our sense of time in order to get more information,” Wiener said.
However, he noted the work does not rule out the possibility that the brain also has an internal clock to keep track of time, which would explain how different aspects of an experience can be perceived in synchrony.
Wiener also said the memory findings had broader implications.
“What it suggests is that if we want time to feel like things are [taking] longer, we need to seek out things that are themselves more memorable. And by that I mean things that are novel and interesting and new to us,” he said. “This is why a vacation can seem to last much longer than, say, the equivalent amount of time during your daily routines.”