title: Egocentric and allocentric spatial representations in Williams syndrome.
abstract: Williams syndrome (WS) is a neurodevelopmental disorder characterized by severe visuospatial deficits, particularly affecting spatial navigation and wayfinding. Creating egocentric (viewer-dependent) and allocentric (viewer-independent) representations of space is essential for the development of these abilities. However, it remains unclear whether egocentric and allocentric representations are impaired in WS. In this study, we investigate egocentric and allocentric frames of reference in this disorder. A WS group (n = 18), as well as a chronological age-matched control group (n = 20), a non-verbal mental age-matched control group (n = 20) and a control group with intellectual disability (n = 17), was tested with a computerized and a 3D spatial judgment task. The results showed that WS participants are impaired when performing both egocentric and allocentric spatial judgments even when compared with mental age-matched control participants. This indicates that a substantial deficit affecting both spatial representations is present in WS. The egocentric impairment is in line with the dorsal visual pathway deficit previously reported in WS. Interestingly, the difficulties found in performing allocentric spatial judgments give important cues to better understand the ventral visual functioning in WS.
authors.affiliation: Visual Neuroscience Laboratory, IBILI, Faculty of Medicine, University of Coimbra, Coimbra, Portugal. ibernardino@fmed.uc.pt
authors.forename: Inês
authors.initials: I
authors.lastname: Bernardino
authors.forename: Susana
authors.initials: S
authors.lastname: Mouga
authors.forename: Miguel
authors.initials: M
authors.lastname: Castelo-Branco
authors.forename: Marieke
authors.initials: M
authors.lastname: van Asselen
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D003463:Cues; D004532:Ego; D005260:Female; D006801:Humans; D007600:Judgment / Q000502:physiology*; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D013028:Space Perception / Q000502:physiology*; D014795:Visual Pathways; D018980:Williams Syndrome / Q000503:physiopathology* / Q000523:psychology*; D055815:Young Adult