title: Apparent speed of sampled motion.
abstract: Perceived speed was measured for stimuli moving unidirectionally in apparent motion with different sampling steps. The stimuli were displayed at successive locations for very brief durations (on-time = 1 msec). The basic result is an elevation of apparent speed produced by increasing the sampling step. This speed-up effect is maximal at low speeds (2 deg/sec), then progressively decreases with higher speeds until it disappears at medium velocities (8 deg/sec). In addition, the speed-up observed at low speeds declines when the ontime is gradually increased from 1 msec to larger values, the largest one corresponding to "staircase motion". These results are consistent with models assuming that speed-encoding is based on an antagonistic comparison of the activity in two broadly tuned temporal filters (low-pass and band-pass). The high temporal frequencies introduced by motion-sampling would activate the band-pass filter relatively more and would thus produce an overestimation of apparent speed.
authors.affiliation: Laboratoire de Psychophysique Sensorielle, Université Louis Pasteur, Strasbourg, France.
authors.forename: E
authors.initials: E
authors.lastname: Castet
mesh_terms: D006801:Humans; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D013997:Time Factors