title: Body-scaled perception is subjected to adaptation when repetitively judging opportunities for grasping.
abstract: Experimental evidence is given that the perceptual system adapts to repetitive task execution in a perceptual two-choice judgment task. Participants were tested with respect to their perception of opportunities for plank grasping. Participants had to report whether planks were perceived as objects being graspable with either one hand or two hands. When the plank size was gradually increased and subsequently decreased, transitions from one hand judgments to two hands judgments and vice versa were observed. Analysis of the transition scores revealed that the perceptual judgments were body-scaled, as it is known in the literature. However, judgments were also found to be context dependent. Judgment transition scores were affected in a systematic way by the kind of and the number of previously made judgments. The latter quantitative impact was observed in three related experiments and suggests that perceptual judgments about opportunities for action adapt to task repetition. Overall, the experimental findings are consistent with the predictions of a dynamical systems model, which assumes that perceptual judgments are emergent properties of a self-organizing process that involves inhibitory top-down feedback.
authors.affiliation: Center for the Ecological Study of Perception and Action, University of Connecticut, 406 Babbidge Rd., Unit 1020, Storrs, CT, 06269-1020, USA.
authors.forename: Seokhun
authors.initials: S
authors.lastname: Kim
authors.affiliation: Center for the Ecological Study of Perception and Action, University of Connecticut, 406 Babbidge Rd., Unit 1020, Storrs, CT, 06269-1020, USA. till.frank@uconn.edu.
authors.forename: Till D
authors.initials: TD
authors.lastname: Frank
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000293:Adolescent; D000328:Adult; D005260:Female; D006225:Hand / Q000502:physiology; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*; D012858:Size Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: Adaptation; Decision making; Size perception; Top-down feedback