title: Invisible collinear structures impair search.
abstract: Visual attention and perceptual grouping both help us from being overloaded by the vast amount of information, and attentional search is delayed when a target overlaps with a snake-like collinear distractor (Jingling & Tseng, 2013). We assessed whether awareness of the collinear distractor is required for this modulation. We first identified that visible long (=9 elements), but not short (=3 elements) collinear distractor slowed observers' detection of an overlapping target. Then we masked part of a long distractor (=9 elements) with continuous flashing color patches (=6 elements) so that the combined dichoptic percept to observers' awareness was a short collinear distractor (=3 elements). We found that the invisible collinear parts, like visible ones, can form a continuous contour to impair search, suggesting that conscious awareness is not a pre-requisite for contour integration and its interaction with selective attention.
authors.affiliation: Department of Psychology, The University of Hong Kong, Hong Kong.
authors.forename: Hiu Mei
authors.initials: HM
authors.lastname: Chow
authors.affiliation: Department of Psychology, The University of Hong Kong, Hong Kong; Department of Psychology, National Taiwan University, Taipei, Taiwan. Electronic address: CH_Tseng@alumni.uci.edu.
authors.forename: Chia-huei
authors.initials: CH
authors.lastname: Tseng
mesh_terms: D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001364:Awareness / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010470:Perceptual Masking; D010775:Photic Stimulation / Q000379:methods*; D013360:Subliminal Stimulation
keywords: Awareness; Collinearity; Invisible; Visual search