Search efficiency is not sufficient: The nature of search modulates stimulus-driven attention

Abstract

It has long been debated whether or not a salient stimulus automatically attracts people's attention in visual search. Recent findings showed that a salient stimulus is likely to capture attention especially when the search process was inefficient due to high levels of competition between the target and distractors. Expanding these studies, the present study proposes that a specific nature of visual search, as well as search efficiency, determines whether or not a salient, task-irrelevant singleton stimulus captures attention. To test this proposition, we conducted three experiments, in which participants performed two visual search tasks whose underlying mechanisms are known to be different: orientation-feature search and Landolt-C search tasks. We found that color singleton distractors captured attention when participants performed the orientation-feature search task. The magnitude of this capture effect increased as search efficiency decreased. On the contrary, the capture by singleton distractors was not observed under the Landolt-C search task. This differential pattern of capture effect was not due to differences in search efficiency across the search tasks; even when search efficiency was controlled for, stimulus-driven capture of attention by a salient distractor was found only under the feature search. Based on these results, the present study suggests that in addition to search efficiency, the nature of search strategy and the extent to which attentional control is strained play crucial roles in observing stimulus-driven attentional capture in visual search.

Saliency-Aware Subtle Augmentation Improves Human Visual Search Performance in VR

“…Other studies demonstrated that salient goal-irrelevant distractors could attract the observer's attention, slowing down the search [13][14][15][16]. The large variability of the results reported in the literature supports the notion that a combination of factors affects human attention guiding when looking for a target [17].…”

“…The priority map is considered to combine the representation of bottom-up object's distinctiveness and its topdown relevance to the observer [84,85]. The impact of saliency in visual search guidance has been debated, where the contribution of saliency is apparent in some tasks at hand [13][14][15][16], but not in others [10][11][12]. The neurophysiological studies also demonstrate a varied saliency contribution in the priority map building across different tasks [84].…”

Opposing effects of stimulus-driven and memory-driven attention in visual search

“…In line with this theory, ample evidence has been found that a salient stimulus, even though it is task-irrelevant, captures attention (Theeuwes, 1992(Theeuwes, , 2004. However, a recent study, along with many other previous studies (Bacon & Egeth, 1994;Barras & Kerzel, 2017;Gaspelin, Ruthruff, & Lien, 2016;Lamy & Egeth, 2003), has shown that capture of attention by a salient stimulus does not always take place; the nature of the search task was found to be critical for observing stimulus-driven attentional capture (Jung, Han, & Min, 2019). In this study, when participants performed the orientation feature search task, a singleton distractor captured attention, whereas the salient distractor failed to capture attention under the Landolt-C search task.…”

“…To address this issue, in the present study we tested whether memory-driven attentional capture is also dependent on how a given search is performed. As in our previous study (Jung et al, 2019), we employed two different visual search tasks whose underlying processes are known to be different: Landolt-C search and orientation feature search.…”

“…The participants in the stimulus-driven attention group also performed either the Landolt-C search or the feature search task. Importantly, several studies have provided evidence that the search efficiency/difficulty of the concurrent visual search task is a crucial factor for observing stimulus-driven attentional capture (Barras & Kerzel, 2017;Gaspelin et al, 2016;Jung et al, 2019;Theeuwes, 2004). To investigate whether task difficulty exerts similar effects on memory-driven attention and to control for the difference in search difficulty across search tasks, we manipulated the task difficulty.…”