title: Search superiority in autism within, but not outside the crowding regime.
abstract: Visual cognition of observers with autism spectrum disorder (ASD) seems to show an unbalance between the complementary functions of integration and segregation. This study uses visual search and crowding paradigms to probe the relative ability of children with autism, compared to normal developments children, to extract individual targets from cluttered backgrounds both within and outside the crowding regime. The data show that standard search follows the same pattern in the ASD and control groups with a strong effect of the set size that is substantially weakened by cueing the target location with a synchronous spatial cue. On the other hand, the crowding effect of eight flankers surrounding a small peripheral target is virtually absent in the clinical sample, indicating a superior ability to segregate cluttered visual items. This data, along with evidence of an impairment to the neural system for binding contours in ASD, bring additional support to the general idea of a shift of the trade-off between integration and segregation toward the latter. More specifically, they show that when discriminability is balanced across conditions, an advantage in odd-man out tasks is evident in ASD observers only within the crowding regime, when binding mechanism might get compulsorily triggered in normal observers.
authors.affiliation: Dipartimento di Psicologia, Università di Firenze, Firenze, Italy; Associazione Italiana di Scienze della Visione, Cascina, Pisa, Italy. stefano.baldassi@unifi.it
authors.forename: Stefano
authors.initials: S
authors.lastname: Baldassi
authors.forename: Francesca
authors.initials: F
authors.lastname: Pei
authors.forename: Nicola
authors.initials: N
authors.lastname: Megna
authors.forename: Giorgia
authors.initials: G
authors.lastname: Recupero
authors.forename: Marco
authors.initials: M
authors.lastname: Viespoli
authors.forename: Roberta
authors.initials: R
authors.lastname: Igliozzi
authors.forename: Raffaella
authors.initials: R
authors.lastname: Tancredi
authors.forename: Filippo
authors.initials: F
authors.lastname: Muratori
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cioni
mesh_terms: D001321:Autistic Disorder / Q000503:physiopathology / Q000523:psychology*; D016022:Case-Control Studies; D002648:Child; D003463:Cues; D004192:Discrimination, Psychological; D005133:Eye Movements / Q000502:physiology*; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011601:Psychophysics