Assessing introspective awareness of attention capture

An examination of the motivation to manage distraction

Individuals exhibit limited awareness of when their attention is captured by salient but irrelevant stimuli, and it has long been argued that involuntary attentional capture by such stimuli is minimally disruptive to information processing. Yet, robust mechanisms of distractor suppression are hypothesized to support the control of attention, which presumably serve in the interest of managing distraction. In the present study, I examine whether participants are aware of the cost of distraction with respect to task performance, and whether they are motivated to manage this cost even when it is effortful to do so. Across three experiments, participants were willing to exert physical effort in order to reduce the frequency with which they encountered physically salient distractors, and in a fourth experiment tended to prefer trials with fewer distractors when given a choice over distractor frequency. Importantly, the amount of physical effort exerted varied as a function of the degree to which task-irrelevant distractors impaired search performance, suggesting that people are sensitive to the cost of distraction.

Attentional suppression of dynamic versus static salient distractors

Attention must be carefully controlled to avoid distraction by salient stimuli. The signal suppression hypothesis proposes that salient stimuli can be proactively suppressed to prevent distraction. Although this hypothesis has garnered much support, most previous studies have used one class of salient distractors: color singletons. It therefore remains unclear whether other kinds of salient distractors can also be suppressed. The current study directly compared suppression of a variety of salient stimuli using an attentional capture task that was adapted for eye tracking. The working hypothesis was that static salient stimuli (e.g., color singletons) would be easier to suppress than dynamic salient stimuli (e.g., motion singletons). The results showed that participants could ignore a wide variety of salient distractors. Importantly, suppression was weaker and slower to develop for dynamic salient stimuli than static salient stimuli. A final experiment revealed that adding a static salient feature to a dynamic motion distractor greatly improved suppression. Altogether, the results suggest that an underlying inhibitory process is applied to all kinds of salient distractors, but that suppression is more readily applied to static features than dynamic features.

Filtering distractors is costly

To find a target in visual search, it is often necessary to filter out task-irrelevant distractors. People find the process of distractor filtering effortful, exerting physical effort to reduce the number of distractors that need to be filtered on a given search trial. Working memory demands are sufficiently costly that people are sometimes willing to accept aversive heat stimulation in exchange for the ability to avoid performing a working memory task. The present study examines whether filtering distractors in visual search is similarly costly. The findings reveal that individuals are sometimes willing to accept an electric shock in exchange for the ability to skip a single trial of visual search, increasingly so as the demands of distractor filtering increase. This was true even when acceptance of shock resulted in no overall time savings, although acceptance of shock was overall infrequent and influenced by a plurality of factors, including boredom and curiosity. These findings have implications for our understanding of the mental burden of distractor filtering and why people seek to avoid cognitive effort more broadly.

The effects of eccentricity on attentional capture

Visual attention may be captured by an irrelevant yet salient distractor, thereby slowing search for a relevant target. This phenomenon has been widely studied using the additional singleton paradigm in which search items are typically all presented at one and the same eccentricity. Yet, differences in eccentricity may well bias the competition between target and distractor. Here we investigate how attentional capture is affected by the relative eccentricities of a target and a distractor. Participants searched for a shape-defined target in a grid of homogeneous nontargets of the same color. On 75% of trials, one of the nontarget items was replaced by a salient color-defined distractor. Crucially, target and distractor eccentricities were independently manipulated across three levels of eccentricity (i.e., near, middle, and far). Replicating previous work, we show that the presence of a distractor slows down search. Interestingly, capture as measured by manual reaction times was not affected by target and distractor eccentricity, whereas capture as measured by the eyes was: items close to fixation were more likely to be selected than items presented further away. Furthermore, the effects of target and distractor eccentricity were largely additive, suggesting that the competition between saliency- and relevance-driven selection was modulated by an independent eccentricity-based spatial component. Implications of the dissociation between manual and oculomotor responses are also discussed.

This is a test: Oculomotor capture when the experiment keeps score

Physically salient stimuli are difficult to ignore, frequently eliciting fixations even when they are known to be task-irrelevant. A recent study demonstrated that distractor fixation-contingent auditory feedback was highly effective in reducing the frequency of fixations on such stimuli. The present study explores more specifically what it is about feedback that makes it effective in curbing oculomotor behavior. In one experiment, we removed the immediacy of the feedback by informing participants after each trial via textual feedback if they had fixated the distractor. A comparable reduction in the frequency of oculomotor capture was observed. In a second experiment, we only provided summary feedback concerning the frequency of oculomotor capture after each block of trials. Not only were the benefits of feedback again robustly comparable, but a benefit was observed even in the first block before any feedback had actually been presented. Simply knowing that the frequency of distractor fixations was being monitored was sufficient to substantially reduce the frequency of oculomotor capture. Interestingly, trial-level feedback predominantly reduced the frequency of capture by slowing oculomotor responses, reflecting a speed-accuracy tradeoff, whereas block-wise feedback resulted in a reduction in the frequency of capture with saccadic reaction time equated, reflecting a bona fide improvement in task performance. Our findings have implications for our understanding of the role of motivation, strategy, and selection history in oculomotor control.

Learning to suppress a location does not depend on knowing which location

The present study investigated whether explicit knowledge and awareness regarding the regularities present in the display affects statistical learning (SL) in visual search. Participants performed the additional singleton paradigm in which a salient distractor was presented much more often in one location than in all other locations. Previous studies have shown that participants learn this regularity as the location that is most likely to contain a distractor becomes suppressed relative to all other locations. In the current study, after each trial, participants had to either indicate the location of the distractor or the location of the target. Those participants that reported the distractor location, were very much aware of the regularity present in the display. However, participants that reported the target location were basically unaware of the regularity regarding the distractor. The results showed no difference between these groups in the amount of suppression of the high-probability location. This indicates that regardless of whether participants had explicit knowledge or not, the suppression was basically the same. We conclude that explicit knowledge and awareness does not contribute to learning to suppress a location. This conclusion is consistent with the notion that statistical learning is automatic, operating without conscious effort or awareness.

Memory precision for salient distractors decreases with learned suppression

Attention operates as a cognitive gate that selects sensory information for entry into memory and awareness (Driver, 2001, British Journal of Psychology, 92, 53-78). Under many circumstances, the selected information is task-relevant and important to remember, but sometimes perceptually salient nontarget objects will capture attention and enter into awareness despite their irrelevance (Adams & Gaspelin, 2020, Attention, Perception, & Psychophysics, 82[4], 1586-1598). Recent studies have shown that repeated exposures with salient distractor will diminish their ability to capture attention, but the relationship between suppression and later cognitive processes such as memory and awareness remains unclear. If learned attentional suppression (indicated by reduced capture costs) occurs at the sensory level and prevents readout to other cognitive processes, one would expect memory and awareness to dimmish commensurate with improved suppression. Here, we test this hypothesis by measuring memory precision and awareness of salient nontargets over repeated exposures as capture costs decreased. Our results show that stronger learned suppression is accompanied by reductions in memory precision and confidence in having seen a color singleton at all, suggesting that such suppression operates at the sensory level to prevent further processing of the distractor object.

Oculomotor feedback rapidly reduces overt attentional capture

People often have limited awareness of the extent to which their attention is captured by salient-but-irrelevant stimuli. In the present study, we examined how providing feedback concerning the frequency of oculomotor capture by such stimuli modulates the control of attention. Our results show that the provision of oculomotor feedback produces a rapid and dramatic decrease in the frequency of distractor fixations. Further probing of this reduction in oculomotor capture by time to fixate the first stimulus revealed further insights into the nature of this experience-dependent effect. A higher frequency of relatively slow fixation latencies was observed in the feedback group, with such responses being generally less prone to capture, reflecting a speed-accuracy tradeoff. Fixations with slower latencies were also associated with a reduced frequency of oculomotor capture in the feedback group, whereas the fastest responses were almost exclusively stimulus-driven across participants and unaffected by feedback. These effects of feedback persisted when feedback was removed and they generalized to novel stimuli. Our findings suggest that, without any instruction concerning how to use the feedback, the oculomotor system defaults to delaying saccadic responses to allow more time for goal-directed influences on selection to come online, reflecting a history-dependent shift in oculomotor processing.

Oculomotor inhibition and location priming in schizophrenia

Schizophrenia is widely thought to involve elevated distractibility, which may reflect a general impairment in top-down inhibitory processes. Schizophrenia also appears to involve increased priming of previously performed actions. Here, we used a highly refined eye-tracking paradigm that makes it possible to concurrently assess distractibility, inhibition, and priming. In both healthy control subjects (HCS, N = 41) and people with schizophrenia (PSZ, N = 46), we found that initial saccades were actually less likely to be directed toward a salient "singleton" distractor than toward less salient distractors, reflecting top-down suppression of the singleton. Remarkably, this oculomotor suppression effect was as strong or stronger in PSZ than in HCS, indicating intact inhibitory control. In addition, saccades were frequently directed to the location of the previous-trial target in both groups, but this priming effect was much stronger in PSZ than in HCS. Indeed, PSZ directed gaze toward the location of the previous-trial target as often as they directed gaze to the location of the current-trial target. These results demonstrate that-at least in the context of visual search-PSZ are no more distractable than HCS and are fully capable of inhibiting salient-but-irrelevant stimuli. However, PSZ do exhibit exaggerated priming, focusing on recently attended locations even when this is not beneficial for goal attainment. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Progress Toward Resolving the Attentional Capture Debate

For over 25 years, researchers have debated whether physically salient stimuli capture attention in an automatic manner, independent of the observer's goals, or whether the capture of attention depends on the match between a stimulus and the observer's task set. Recent evidence suggests an intermediate position in which salient stimuli automatically produce a priority signal, but the capture of attention can be prevented via an inhibitory mechanism that suppresses the salient stimulus. Here, proponents from multiple sides of the debate describe how their original views have changed in light of recent research, as well as remaining areas of disagreement. These perspectives highlight some emerging areas of consensus and provide new directions for future research on attentional capture.