DOI:10.6129/CJP.202103_63(1).0001
Chinese Journal of Psychology 2021, Vol.63, No.1, 1-22

Perceptual Grouping Strength can Modulate the Size of the Collinear Masking Effect in a isual Search

Yen-Ting Liu（Graduate Institute of Biomedical Sciences, China Medical University）；Li Jingling（Graduate Institute of Biomedical Sciences, China Medical University）

Abstract

Visual search efficiency can usually be promoted if the target is salient. However, Jingling & Tseng (2013) found that if the salient structure was composed of collinear bars, search would be more difficult — a phenomenon called the collinear masking effect. In their experiment, the collinear structure was composed of bars in a head-to-tail alignment. Thus, it is possible that perceptual grouping of the collinear distractor may play a role in the collinear masking effect. The current study aimed to reduce the strength of the perceptual grouping of the whole search display and to test whether the size of collinear masking effect also reduced. In Experiment 1, the scale of the bars (the size ratios of bars and spacing) was increased, and in Experiment 2, the spacing between bars was increased to reduce the grouping strength of the whole display. In Experiment 3, possible confounding of bar orientation of the target was removed. Our data showed that the strength of the collinear masking effect was indeed reduced because of the weakening of the perceptual grouping of the search display. Simply changing the orientation of the bar where target was on did not affect responses. We infer that the reduction of perceptual grouping strength of the whole display also reduced the grouping strength of collinear distractor, and hence the size of the effect. Therefore, collinearity grouping strength might be an important factor for the emergence of the collinear masking effect.

Keywords: collinear masking effect, perceptual grouping, perceptual salience, visual search