Time passes slower when we see people moving

Recent research led by a scientist from the University of Coimbra

A recent investigation led by a scientist from the University of Coimbra, published in the journal Experimental Brain Research, concluded that the human being has the perception that time passes more slowly when biological movements are observed, when compared to artificial movements.

The study took place at the Federal University of ABC (São Paulo, Brazil) and had the collaboration of 32 participants. The team sought to know how the human being assesses the elapsed time when viewing a video that mimics the movement of a human body running (biological movement) and another one in a geometric shape moving like a pendulum (artificial movement).

Although the stimuli have the same duration, the participants considered that the biological movement lasts longer than the artificial one at plausible speeds.

“Since human movement is more complex, the way we perceive and process this visual stimulus is different and probably more complex than the way we perceive visual stimuli from artificial objects. For this reason, the participants believe that the duration of the human movement stimulus is greater than the duration of the artificial stimulus”, explains Giuliana Giorjiani, now a researcher at the Proaction Lab responsible for the study.

The researchers also varied the speed of the videos, increasing and decreasing the number of frames (or frames) per second in order to find the speed made biological movement more natural. Next, they verified what was happening in the brain, namely in a region called the Superior Temporal Sulcus (STS), which is known to respond to human movement and form.

To do this, they used a technique called Functional Near-Infrared Light Spectroscopy which, similarly to oximeters that are placed at the fingertips of patients in a hospital, measure the presence of oxygen in the blood.

“By measuring the amount of hemoglobin in the blood with and without oxygen, we were able to verify that there was greater activity in the STS when the participants visualized biological movement in relation to the artificial one”, explains the researcher.

The human brain is still a big mystery to researchers. “We know that our brain has several biases, such as the perception of time. Knowing how these processes work can help society to use them in our favor”, he concludes.

A demonstration of the stimuli is available at https://youtu.be/0Lkg1F3ZEIc

Giorjiani, GM, Biazoli, CE & Caetano, MS Differences in perceived durations between plausible biological and non-biological stimuli. Exp Brain Res (2020) https://doi.org/10.1007/s00221-020-05904-w


Author Daniel Ribeiro (Proaction lab)
© 2021 – Science in the Regional Press / Ciência Viva
Daniel Ribeiro is a biologist from the University of Minho and a Master in Science Communication from the Universidade Nova de Lisboa. He has already worked as a Science Communicator at i3S – Institute for Research and Innovation in Health, in Porto, as well as at the National Museum of Natural History and Science, in Lisbon.
He is currently part of the communication team of the PROACTION Lab, a research laboratory in Psychology/Neurosciences of the Faculty of Psychology and Educational Sciences of the University of Coimbra, focused on the perception and recognition of objects and actions.