title: Predictable and self-initiated visual motion is judged to be slower than computer generated motion.
abstract: Self-initiated action effects are often perceived as less intense than identical but externally generated stimuli. It is thought that forward models within the sensorimotor system pre-activate cortical representations of predicted action effects, reducing perceptual sensitivity and attenuating neural responses. As self-agency and predictability are seldom manipulated simultaneously in behavioral experiments, it is unclear if self-other differences depend on predictable action effect contingencies, or if both self- and externally generated stimuli are modulated similarly by predictability. We factorially combined variation in (1) predictability of action effects, (2) spatial congruence, and (3) performance by the self or computer to dissociate these influences on a visual discrimination task. Participants performed 2AFC speed judgments. Self-initiated motion was judged to be slower than computer-initiated motion when action effect contingencies were predictable, while spatial congruence influenced speed judgments only when action effect contingencies were unpredictable. Results are discussed in relation to current theories of sensory attenuation.
authors.affiliation: Department of Cognitive Science, Central European University, Frankel Leó út 30-34, Budapest 1023, Hungary. Electronic address: DeweyJ@ceu.hu.
authors.forename: John A
authors.initials: JA
authors.lastname: Dewey
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Carr
mesh_terms: D000293:Adolescent; D000328:Adult; D003198:Computer Simulation; D005260:Female; D006801:Humans; D007389:Internal-External Control; D007600:Judgment / Q000502:physiology; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D009068:Movement / Q000502:physiology; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance; D012649:Self Concept; D014796:Visual Perception; D055815:Young Adult
keywords: Action effect; Agency; Forward model; Sensory attenuation