title: Adaptation of egocentric distance perception under telestereoscopic viewing within reaching space.
abstract: Telestereoscopic viewing provides a method to distort egocentric distance perception by artificially increasing the interpupillary distance. Adaptation to such a visual rearrangement is little understood. Two experiments were performed in order to dissociate the effects of a sustained increased vergence demand, from those of an active calibration of the vergence/distance mapping. Egocentric distances were assessed within reaching space through open-loop pointing to small targets in the dark. During the exposure condition of the first experiment, subjects were instructed to point to the targets without feedback, whereas in the second experiment, hand visual feedback was available, resulting in a modified relationship between vergence-specified distance and reach distance. The visual component of adaptation in the second experiment was assessed on the unexposed hand. In the post-tests of both experiments, subjects exhibited a constant distance overestimation across all targets, with a more than twice larger aftereffect in the second one. These findings suggest two different processes: (1) an alteration in the vergence effort following sustained increased vergence; (2) a calibration of the vergence/distance mapping uncovering the visual component of adaptation.
authors.affiliation: Institut de recherche biomédicale des armées, Brétigny-sur-Orge, France.
authors.forename: Anne-Emmanuelle
authors.initials: AE
authors.lastname: Priot
authors.forename: Rafael
authors.initials: R
authors.lastname: Laboissière
authors.forename: Olivier
authors.initials: O
authors.lastname: Sillan
authors.forename: Corinne
authors.initials: C
authors.lastname: Roumes
authors.forename: Claude
authors.initials: C
authors.lastname: Prablanc
mesh_terms: D000223:Adaptation, Psychological; D000328:Adult; D001828:Body Image; D003624:Darkness; D030141:Feedback, Psychological; D005260:Female; D006225:Hand; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D010775:Photic Stimulation; D011597:Psychomotor Performance; D011601:Psychophysics; D013028:Space Perception; D013647:Task Performance and Analysis; D014796:Visual Perception; D055815:Young Adult