title: Adding temporally localized noise can enhance the contribution of target knowledge on contrast detection.
abstract: External noise paradigms are widely used to characterize sensitivity by comparing the effect of a variable on contrast threshold when it is limited by internal versus external noise. A basic assumption of external noise paradigms is that the processing properties are the same in low and high noise. However, recent studies (e.g., Allard & Cavanagh, 2011; Allard & Faubert, 2014b) suggest that this assumption could be violated when using spatiotemporally localized noise (i.e., appearing simultaneously and at the same location as the target) but not when using spatiotemporally extended noise (i.e., continuously displayed, full-screen, dynamic noise). These previous findings may have been specific to the crowding and 0D noise paradigms that were used, so the purpose of the current study is to test if this violation of noise-invariant processing also occurs in a standard contrast detection task in white noise. The rationale of the current study is that local external noise triggers the use of recognition rather than detection and that a recognition process should be more affected by uncertainty about the shape of the target than one involving detection. To investigate the contribution of target knowledge on contrast detection, the effect of orientation uncertainty was evaluated for a contrast detection task in the absence of noise and in the presence of spatiotemporally localized or extended noise. A larger orientation uncertainty effect was observed with temporally localized noise than with temporally extended noise or with no external noise, indicating a change in the nature of the processing for temporally localized noise. We conclude that the use of temporally localized noise in external noise paradigms risks triggering a shift in process, invalidating the noise-invariant processing required for the paradigm. If, instead, temporally extended external noise is used to match the properties of internal noise, no such processing change occurs.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, Paris, Francedaphne.silvestre@inserm.frwww.aging-vision-action.fr.
authors.forename: Daphné
authors.initials: D
authors.lastname: Silvestre
authors.affiliation: Laboratoire Psychologie de la Perception, Université Paris Descartes, Paris, Francepatrick.cavanagh@parisdescartes.frwww.aging-vision-action.fr.
authors.forename: Patrick
authors.initials: P
authors.lastname: Cavanagh
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, Paris, Franceangelo.arleo@inserm.frhttp://www.aging-vision-action.fr.
authors.forename: Angelo
authors.initials: A
authors.lastname: Arleo
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, INSERM, CNRS, Institut de la Vision, Paris, Franceremy.allard@inserm.frwww.aging-vision-action.fr.
authors.forename: Rémy
authors.initials: R
authors.lastname: Allard
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009622:Noise; D009949:Orientation; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D035501:Uncertainty; D055815:Young Adult