title: Effects of speeding up or slowing down animate or inanimate motions on timing.
abstract: It has recently been suggested that time perception and motor timing are influenced by the presence of biological movements and animacy in the visual scene. Here, we investigated the interactions among timing, speed and animacy in two experiments. In Experiment 1, observers had to press a button in synchrony with the landing of a falling ball while a dancer or a whirligig moved in the background of the scene. The speed of these two characters was artificially changed across sessions. We found striking differences in the timing of button-press responses as a function of the condition. Responses were delayed considerably with increasing speed of the whirligig. By contrast, the effect of the dancer's speed was weaker and in the opposite direction. In Experiment 2, we assessed the perceived animacy of these characters and found that the dancer was rated as much more animate than the whirligig, irrespective of the character speed. The results are consistent with the hypothesis that event timers are selectively biased as a function of perceived animacy, implicating high-level mechanisms for time modulation. However, response timing interacts with perceived animacy and speed in a complex manner.
authors.affiliation: Cell Biology and Neurobiology Institute, National Research Council, 00143, Rome, Italy. m.carrozzo@hsantalucia.it
authors.forename: Mauro
authors.initials: M
authors.lastname: Carrozzo
authors.forename: Francesco
authors.initials: F
authors.lastname: Lacquaniti
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology*; D013997:Time Factors; D013998:Time Perception / Q000502:physiology*; D055815:Young Adult