Perceptual load and the capture of spatial attention by color singletons

Recent experiments have cast considerable doubt upon the ability of color singletons to capture spatial attention in a stimulus-driven manner. Despite the lack of evidence for it in the laboratory, there are many anecdotal reports of stimulus-driven capture in real-world settings. Perhaps a critical difference between laboratory and real-world visual scenes is the amount of relevant information, or perceptual load. Scenes with low perceptual load (as when one is focused on a single visual object) might free attentional resources, allowing them to be more easily captured by color singletons. To test this hypothesis, we manipulated perceptual load in a visual search task with irrelevant flanking letters that were sometimes color singletons. If reduced perceptual load increases susceptibility to capture by color singletons, then the presence of a color singleton should slow responses and increase flanker-target compatibility effects. Contrary to this prediction, we found no evidence of capture under high or low perceptual load

“Top-down” Does Not Mean “Voluntary”

Attention researchers have long debated the roles of top-down and bottom-up mechanisms in controlling attention. Theeuwes (2018) has argued that that top-down control is much less common than typically assumed and that a third mechanism—selection history—plays an underappreciated role in guiding visual attention. Although Theeuwes has made a strong case for the importance of selection history, his arguments for a limited role of top-down mechanisms involve conflating the terms “top-down” and “voluntary.” Cognitive psychologists typically use the term “top-down” processing to refer to any perceptual phenomenon that is influenced by context, learning, or expectation, which would include selection history. This highlights a broad problem in attention capture research: The terms used to describe attentional control are often poorly defined, and much current debate seems to be related to the meaning of words. To move forward in understanding the actual mechanisms of attentional control, we must agree on what terms such as “top-down” and “bottom-up” actually mean

Breaking through the attentional window: Capture by abrupt onsets versus color singletons

Theeuwes (2004) proposed that stimulus-driven capture occurs primarily for salient stimuli that fall within the observer's attentional window, such as when performing a parallel search. This proposal, supported by some studies, can explain many seemingly discrepant results in the literature. The present study tested this proposal using a modified pre-cuing paradigm. Search mode was manipulated via target-distractor similarity in color space. In the parallel search condition, the orange target “popped out” from a set of distantly colored distractors (blue and green). In the serial search condition, the orange target was more difficult to find amongst a set of similarly colored distractors (yellow and red). In Experiments 1 and 2, cue validity effects for irrelevant color singleton cues were greater under parallel search than serial search, at least partially replicating previous studies favoring the attentional window account (e.g., Belopolsky et al., 2007). We found the opposite pattern, however, for capture by abrupt onsets (Experiments 3 and 4). Here, capture effects were actually greater under serial search. In sum, parallel search appears to facilitate capture by color singletons, yet inhibit capture by abrupt onsets.Keywords: attentional capture, visual search, spatial attentio

Terms of debate: consensus definitions to guide the scientific discourse on visual distraction

Hypothesis-driven research rests on clearly articulated scientific theories. The building blocks for communicating these theories are scientific terms. Obviously, communication – and thus, scientific progress – is hampered if the meaning of these terms varies idiosyncratically across (sub)fields and even across individual researchers within the same subfield. We have formed an international group of experts representing various theoretical stances with the goal to homogenize the use of the terms that are most relevant to fundamental research on visual distraction in visual search. Our discussions revealed striking heterogeneity and we had to invest much time and effort to increase our mutual understanding of each other’s use of central terms, which turned out to be strongly related to our respective theoretical positions. We present the outcomes of these discussions in a glossary and provide some context in several essays. Specifically, we explicate how central terms are used in the distraction literature and consensually sharpen their definitions in order to enable communication across theoretical standpoints. Where applicable, we also explain how the respective constructs can be measured. We believe that this novel type of adversarial collaboration can serve as a model for other fields of psychological research that strive to build a solid groundwork for theorizing and communicating by establishing a common language. For the field of visual distraction, the present paper should facilitate communication across theoretical standpoints and may serve as an introduction and reference text for newcomers