Why Do Actions in Slow Motion Appear to Last Longer? On the Effect of Video Speed Information

The impact of physical load on duration estimation in sport

We investigated whether physical load has an influence on the accuracy of duration estimation of sporting activities presented in real time and slow motion. 86 participants were studied in two single sessions of 45 min each. Our results showed no general effects for physical load, when comparing physical load versus rest. However, we could replicate findings of past research (Schütz et al., 2021), showing that the duration of sports performance is estimated more accurately when presented in real time compared to slow motion. Further we found, that under physical load, participants perceiving the physical exercise as hard (RPE ≥15) estimated time significantly shorter and more accurately compared to participants perceiving the physical exercise as light or moderate (RPE <15). Thus, our results suggest that using slow motion may worsen the assessment of sports performance. Additionally, we could show that intense physical exertion contributes to reducing the overestimation of time.

Slow motion bias: Exploring the relation between time overestimation and increased perceived intentionality

Recent research on time perception has revealed that actions which are replayed in slow motion are perceived to take longer and rated to be more intentional (e.g., foul plays). Interestingly, the bias on duration estimations seems to disappear when information on the slow motion factor (i.e., the degree the video was slowed down) was provided. Here, we scrutinize the question whether also the intentionality bias disappears when explicit information about the slow motion factor is provided. To this end, two groups watched the same video clips, all displaying foul situations in a basketball match, in different video speeds. While the uninformed group saw the videos without further information, the informed group received additional information about the current slow motion factor. This study replicated the overestimation of original duration with increasing slow motion and indicated that this effect might be reduced when information about the slow motion factor is provided. However, despite generally lower intentionality ratings in the informed group, video speed information was not able to reduce the rise in intentionality ratings with increasing slow motion. Potential reasons and open questions regarding the nature and mechanisms behind these perceptual temporal biases (e.g., different time processing systems) are discussed.

Basketball videos presented on a computer screen appear slower than in virtual reality

Decision-making skills are essential to successful performance. To train them, coaches frequently use video replays to show their athletes how to best respond when facing specific situations. Recently, it has been shown that presenting the videos in virtual reality (VR) led to enhanced transfer, from the laboratory to the playing field, compared to when the videos were presented on a standard computer screen (CS). Interestingly, although the videos were identical, many participants informally reported that the VR videos felt accelerated compared to those they usually see on television. Here, we tested this claim by having varsity-level basketball players perform a decision-making task concomitantly with a playback speed estimation task. All participants observed the same video clips in the VR and CS conditions, and the video clips were either presented at their normal speed or had been accelerated or decelerated by 10%. Our results revealed that participants perceived the VR videos as significantly faster than the CS videos (mean perceived playback speed of 100.7% ± 2.35% and 94.9% ± 2.24%, respectively). This difference was, however, caused by the CS videos appearing slower than they truly were. Our results indicate that VR videos appear immune to the speed underestimation frequently reported with CS videos.