title: Early Binocular Input Is Critical for Development of Audiovisual but Not Visuotactile Simultaneity Perception.
abstract: Temporal simultaneity provides an essential cue for integrating multisensory signals into a unified perception. Early visual deprivation, in both animals and humans, leads to abnormal neural responses to audiovisual signals in subcortical and cortical areas [1-5]. Behavioral deficits in integrating complex audiovisual stimuli in humans are also observed [6, 7]. It remains unclear whether early visual deprivation affects visuotactile perception similarly to audiovisual perception and whether the consequences for either pairing differ after monocular versus binocular deprivation [8-11]. Here, we evaluated the impact of early visual deprivation on the perception of simultaneity for audiovisual and visuotactile stimuli in humans. We tested patients born with dense cataracts in one or both eyes that blocked all patterned visual input until the cataractous lenses were removed and the affected eyes fitted with compensatory contact lenses (mean duration of deprivation = 4.4 months; range = 0.3-28.8 months). Both monocularly and binocularly deprived patients demonstrated lower precision in judging audiovisual simultaneity. However, qualitatively different outcomes were observed for the two patient groups: the performance of monocularly deprived patients matched that of young children at immature stages, whereas that of binocularly deprived patients did not match any stage in typical development. Surprisingly, patients performed normally in judging visuotactile simultaneity after either monocular or binocular deprivation. Therefore, early binocular input is necessary to develop normal neural substrates for simultaneity perception of visual and auditory events but not visual and tactile events.
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada; Department of Experimental Psychology, University of Oxford, 9 South Parks Road, Oxford OX1 3UD, UK.
authors.forename: Yi-Chuan
authors.initials: YC
authors.lastname: Chen
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada; Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada.
authors.forename: Terri L
authors.initials: TL
authors.lastname: Lewis
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada.
authors.forename: David I
authors.initials: DI
authors.lastname: Shore
authors.affiliation: Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4K1, Canada; Department of Ophthalmology and Vision Sciences, The Hospital for Sick Children, 555 University Avenue, Toronto, ON M5G 1X8, Canada. Electronic address: maurer@mcmaster.ca.
authors.forename: Daphne
authors.initials: D
authors.lastname: Maurer
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001307:Auditory Perception / Q000502:physiology*; D002386:Cataract / Q000151:congenital; D002387:Cataract Extraction; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D055698:Touch Perception / Q000502:physiology*; D015348:Vision, Binocular; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult
keywords: audiovisual perception; congenital cataract; crossmodal perception; early visual experience; multisensory perception; simultaneity perception; visual deprivation; visuotactile perception