A recent scientific study published in Experimental Brain Research has discovered that humans perceive that time passes by slower when they observe biological movement as opposed to non-biological movement.
The study was conducted at the Federal University of ABC (São Paulo, Brazil) and gathered data from 32 participants. The researchers’ goal was to evaluate how humans perceive the elapsed time when watching a video of a person running (biological movement) and a non-biological geometrical shape moving back and forth.
Although both have the same exact duration of 15 seconds, participants believed that the biological stimulus lasted longer than the non-biological one. But why?
“Since the human movement is more complex, the way we understand and process that visual stimulus is different and most likely more complex than when we process non-biological movement of objects. For that reason, participants think the duration of the biological stimulus is higher,” explains Giuliana Giorjiani, the lead researcher now working at the University of Coimbra.
The team of researchers also played with stimuli speeds, increasing and decreasing frame rates in order to find the speed that made the biological stimulus seem more natural. With that in mind, they studied what exactly happened in the brain, namely the superior temporal sulcus (STS), known to process information related to movement and the human shape.
For that, they used a technique called functional near infrared spectroscopy (fNIRS) that, similarly to some fit bands and watches, measures blood oxygenation levels.
“By measuring the amount of oxygenated and non-oxygenated hemoglobin, we verified there is an increased activity of the STS region when participants watched the biological movement stimulus compared to the movement of a geometric shape,” clarifies the researcher.
The human brain is yet a great mystery to the scientific community. “We know our brain has many biases, such as the perception of time. By knowing how these biases work, we might be able to help society using them in our favor,” he concludes.
The study, “Differences in perceived durations between plausible biological and non-biological stimuli“, was authored by Giuliana Martinatti Giorjiani, Claudinei Eduardo Biazoli Jr. and Marcelo Salvador Caetano.