# Time and video speed perception: a comprehensive investigation of the relation between estimated video speed, clip duration and original duration

## TL;DR

This study explores how people perceive video speed and duration, finding that altered video speeds can distort perception, which may impact decision-making.

## Contribution

The study provides new empirical evidence on how video speed manipulation affects human perception of time and duration.

## Key findings

- Participants underestimated video speed in time lapse and overestimated it in slow motion.
- Estimations of clip and original duration were highly correlated but uncorrelated with estimated video speed.
- Distorted perception of original duration may stem from biased interpretations of clip duration and speed.

## Abstract

While decades of research have deepened our understanding of time perception, the perception of (manipulated) video speed has been relatively underexplored but is gaining interest with recent technological advances. This study systematically investigated human perception of video speed, clip duration and original duration across slow motion, original speed and time lapse. Results showed that participants consistently underestimated video speed in time lapse and overestimated it in slow motion, suggesting a tendency toward an internal perceptual standard. A similar pattern emerged for clip duration with videos being generally overestimated in their duration when played in accelerated speed, and underestimated in slow motion. For original duration estimations, this pattern was reversed. Surprisingly, while estimations of clip and original duration were highly correlated in all video speed conditions, both measures were uncorrelated with estimated video speed. However, an exploratory analysis suggested that the distorted perception of original duration may, at least in parts, still be rooted in participants relying on their own (but biased) interpretations of clip duration and video speed. Most importantly, these results reveal distortions in perception caused by altered video speeds, suggesting caution when employing these video techniques for judgments and decision-making. The findings provide foundation for further research, investigating the cognitive mechanisms of human video speed perception.

The online version contains supplementary material available at 10.1186/s41235-025-00637-2.