Videos look faster as children grow up: Sense of speed and impulsivity throughout primary school

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.

If You Are Old, Videos Look Slow. The Paradoxical Effect of Age-Related Motor Decline on the Kinematic Interpretation of Visual Scenes

Perception and action are tightly coupled. However, there is still little recognition of how individual motor constraints impact perception in everyday life. Here we asked whether and how the motor slowing that accompanies aging influences the sense of visual speed. Ninety-four participants aged between 18 and 90 judged the natural speed of video clips reproducing real human or physical motion (SoS, Sense-of-Speed adjustment task). They also performed a finger tapping task and a visual search task, which estimated their motor speed and visuospatial attention speed, respectively. Remarkably, aged people judged videos to be too slow (speed underestimation), as compared to younger people: the Point of Subjective Equality (PSE), which estimated the speed bias in the SoS task, was +4% in young adults (<40), +12% in old adults (40–70) and +16% in elders. On average, PSE increased with age at a rate of 0.2% per year, with perceptual precision, adjustment rate, and completion time progressively worsening. Crucially, low motor speed, but not low attentional speed, turned out to be the key predictor of video speed underestimation. These findings suggest the existence of a counterintuitive compensatory coupling between action and perception in judging dynamic scenes, an effect that becomes particularly germane during aging.

Cortical Resonance to Visible and Invisible Visual Rhythms

Humans are rather poor in judging the right speed of video scenes. For example, a soccer match may be sped up so as to last only 80 min without observers noticing it. However, both adults and children seem to have a systematic, though often biased, notion of what should be the right speed of a given video scene. We therefore explored cortical responsiveness to video speed manipulations in search of possible differences between explicit and implicit speed processing. We applied sinusoidal speed modulations to a video clip depicting a naturalistic scene as well as a traditional laboratory visual stimulus (random dot kinematogram, RDK), and measured both perceptual sensitivity and cortical responses (steady-state visual evoked potentials, SSVEPs) to speed modulations. In five observers, we found a clear perceptual sensitivity increase and a moderate SSVEP amplitude increase with increasing speed modulation strength. Cortical responses were also found with weak, undetected speed modulations. These preliminary findings suggest that the cortex responds globally to periodic video speed modulations, even when observers do not notice them. This entrainment mechanism may be the basis of automatic resonance to the rhythms of the external world.