Collinear search impairment is luminance contrast invariant

Abstract

Collinear search impairment (CSI) is a phenomenon where a task-irrelevant collinear structure impairs a target search in a visual display. It has been suggested that CSI is monocular, occurs without the participants’ access to consciousness and is possibly processed at an early visual site (e.g. V1). This effect has frequently been compared with a well-documented opposite effect called attentional capture (AC), in which salient and task-irrelevant basic features (e.g. color, orientation) enhance target detection. However, whether this phenomenon can be attributed to non-attentional factors such as collinear facilitation (CF) has not yet been formally tested. Here we used one well-established property of CF, i.e. that target contrast modulates its effect direction (facilitation vs suppression), to examine whether CSI shared similar signature profiles along different contrast levels. In other words, we tested whether CSI previously observed at the supra-threshold level was reduced or reversed at near-threshold contrast levels. Our results showed that, regardless of the luminance contrast levels, participants spent a longer time searching for targets displayed on the salient singleton collinear structure than those displayed off the structure. Contrast invariance suggests that it is unlikely that CSI is exclusively sub-served by an early vision mechanism (e.g. CF).

Testing the effect of display organization in the collinear search impairment

“…Nevertheless, a shape target (Tseng & Jingling, 2015) or a brighter/dimmer target (Jingling et al, 2017) still being masked by the collinear distractors. Alternatively, the collinear grouping via lateral connections may induce perceptual filling-in (Zhaoping & Jingling, 2008) and smear the target visibility; however, Tseng et al (2021) found that lowered down the luminance of bars to the threshold level (which should avoid collinear grouping via lateral connections) did not remove collinear search impairment. Another possibility is that the collinear grouping may provide location information that interferes location uncertainty of attentional distribution (Shioiri et al, 2016), which might lead to reduce uncertainty to the non-overlapping target more than overlapping targets.…”

“…Such saliency could enhance target search if the target happens to overlap with a salient item, compare to the target non-overlapping with a salient item (Turatto & Galfano, 2001; Turatto et al, 2004; Yantis & Jonides, 1984). Nevertheless, the combination of orientation singleton and good continuity, which is “super salient” (Jingling & Zhaoping, 2008), counterintuitively impairs visual search (Jingling et al, 2017; Jingling & Tseng, 2013; Tseng et al, 2021; Tseng & Jingling, 2015). In particular, a local target that overlapped with a collinear structure is identified slower and less accurate than that non-overlapped with the collinear structure.…”

Testing the effects of perceptual grouping on visual search in older adults

“…Relative salience between the target and the distractor 6 , attentional control setting on task demands 6,12 , and attentional focus size 5 could not alter such search impairment. In addition, such impairment was still observed when the luminance of items in a search display to threshold levels was decreased, suggesting that collinear facilitation mechanism in the early visual cortex could not explain the effect 11 . Nevertheless, the collinear search impairment is associated with the grouping strength of the collinear distractor: the longer the collinear distractor, the stronger the observed impairment 8 .…”

“…The current study focused on the collinear search impairment, an impairment in visual search induced by collinear grouping previously observed in younger adults [5][6][7][8][9][10][11][12] . In our previous study, collinear search impairment was demonstrated when a local target overlapped with a collinear structure (Figure 1A): an impairment compared to the condition where the target was in the background.…”

Testing the effects of perceptual grouping on visual search in older adults

“…Relative salience between the target and the distractor 11 , 15 , attentional control setting on task demands 11 , 17 , and attentional focus size 10 could not alter such search impairment. The critical processing for the collinear search impairment was inferred to be at or beyond neural computations in the early visual cortex 16 , 22 . Nevertheless, the collinear search impairment is associated with the grouping strength of the collinear distractor: the longer the collinear distractor, the stronger the observed impairment 13 .…”