The present study aimed at testing the general assumption that virtual reality can enhance the experience of exercising. More specifically, we tested the effects of sensory input (music and video feedback) during physical training on performance, enjoyment, and attentional focus by means of a computerized ergometer coupled with VR software. Twelve university students participated in the study. The experimental procedure consisted in a 2 × 3 × 4 mixed design, with two types of feedback (video feedback vs. video feedback and music), three course phases (e.g., flat, uphill, and downhill) and four sessions (task repetition). The virtual feedback was a video film of the course that participants had to complete. Video display speed was proportional to the participant's pedaling speed. Force feedback, applied to the real bicycle wheel, was proportional to the instantaneous course slope. The results showed a positive effect of task repetition on participants' performance only when video feedback was associated with listening to music. In an attempt to objectively assess attentional focus, we analyzed participants' gaze orientation. Gaze analysis showed a reduction in the time spent gazing at video feedback across sessions. Associating video feedback with freely chosen music led to a differential use of video feedback as a function of exercise intensity. Finally, sensory stimulation appeared to have a dissociative role on participants' attentional focus during exercise, but adding music listening to video feedback appears to be necessary to maintain (long term) the participants' commitment to the task. The results are discussed in terms of the functional status of sensory stimulation during exercise, and its interactions with exercise intensity, participants' performance, and attentional focus. They also suggest that gaze analysis is one promising way to access attention allocation and its relationships with performance.

Information specifying the future passing distance of an approaching object is available (in units of object size) in the ratio of optical displacement velocity and optical expansion velocity. Despite empirical support for the assumption that object size can serve as a metric in the perception of passing distance, the present series of experiments reveals that in catching a ball subjects do not rely on such "point-predictive" information. The angle at which (real and simulated) balls approached the subject systematically affected verbal and manual estimates of future passing distance, as well as the kinematic characteristics of catching movements. To catch a ball, the actor uses momentary action-related information instead of spatiotemporal estimates. The hand velocity is geared to information specifying the currently required velocity. This secures ending up at the right place in the right time, regardless of where this may be.

The perceived direction of a grating moving behind an elongated aperture is biased towards the aperture's long axis. This “barber pole” illusion is a consequence of integrating one-dimensional (1D) or grating and two-dimensional (2D) or terminator motion signals. In humans, we recorded the ocular following responses to this stimulus. Tracking was always initiated at ultra-short latencies (≈ 85 ms) in the direction of grating motion. With elongated apertures, a later component was initiated 15–20 ms later in the direction of the terminator motion signals along the aperture's long axis. Amplitude of the later component was dependent upon the aperture's aspect ratio. Mean tracking direction at the end of the trial (135–175 ms after stimulus onset) was between the directions of the vector sum computed by integrating either terminator motion signals only or both grating and terminator motion signals. Introducing an elongated mask at the center of the “barber pole” did not affect the latency difference between early and later components, indicating that this latency shift was not due to foveal versus peripheral locations of 1D and 2D motion signals. Increasing the size of the foveal mask up to 90% of the stimulus area selectively reduced the strength of the grating motion signals and, consequently, the amplitude of the early component. Conversely, reducing the contrast of, or indenting the aperture's edges, selectively reduced the strength of terminator motion signals and, consequently, the amplitude of the later component. Latencies were never affected by these manipulations. These results tease apart an early component of tracking responses, driven by the grating motion signals and a later component, driven by the line-endings moving at the intersection between grating and aperture's borders. These results support the hypothesis of a parallel processing of 1D and 2D motion signals with different temporal dynamics.