Watching a video at the wrong speed and not perceiving any difference

The Psychology UniSR research published on Scientific Reports

Video-indifference and perception jokes: watching a video at the wrong speed and not noticing any difference

Watching an altered video – at lower or faster speed – and not noticing any difference. This is the curious and surprising result of a study by UniSR researchers published on the prestigious Scientific Reports journal, which explores the low perceptual sensitivity at different speeds of a video shown. The authors of the study, conducted at the Laboratory of Action Perception and Cognition of the University, are Prof. Claudio de’Sperati, Associate Professor of Psychophysiology at the Faculty of Psychology and Head of the Unit of Experimental Psychology the San Raffaele Neuroscience Division, and Dr. Gabriel Baud-Bovy, Researcher at the same Faculty and Professor of Psychophysics and Artificial Intelligence.

By using the rigorous experimental paradigms of psychophysics, the two neuroscientists found that accelerating or slowing down a video of a soccer match, even of 10%, goes completely unnoticed.

“We presented the videos to various groups of subjects” says Dr. Baud-Bovy, “trying to figure out if, changing their speed, they had an impression of such manipulations. What we observed is that none of the participants perceived the change of speed, despite the video shown is a very familiar visual stimulus”.

“The study shows how our sense of reality is weak when we look at a video” comments Professor de’Sperati, “even when it comes to a fundamental dimension of experience like the flow of time – not simply psychological but precisely the time of what passes before our eyes”.

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What impact can the results achieved have on a social level? “We live in a world where images, even those in motion, are increasingly artificial. Not only cinema and TV, but also video games, virtual reality and videoclips of all kinds are becoming the everyday nature, especially for the new generations” Prof. de’Sperati finally reflects. “The consequences can be resounding: just think what could change in the tournaments if soccer matches would last, let’s say, 80 minutes – a condition that, according to this study, does not ruin the sense of normality. We should probably get ready for a video system where video speeds will be increasingly pushed, not only in terms of special effects and rhythms of action, things we are already used to, but also in terms of an imperceptible yet not negligible general video acceleration. Then maybe we would have to resort to some “video-diet” of scenes made imperceptibly slower”.