Learned distractor rejection persists across target search in a different dimension.

Attention is guided by several factors, including task-relevant target features, which attract attention, but also statistical regularities associated distractors, which repel attention away from themselves. However, whether feature-based distractor regularities (e.g., color) are extracted automatically from a feature dimension orthogonal to the target-guiding dimension (e.g., shape) remains to be tested. In two experiments, we tested if learned distractor rejection by color operated when color was not part of the attentional control settings, specifically, while attention was guided by a shape-based target template. Participants performed a visual search task for a task-relevant shape in displays containing two unsegregated colors. These displays allowed us to manipulate target guidance (based on shape) independently from distractor-based regularities (based on color). In both experiments we found clear evidence for learned distractor rejection: faster mean response times to locate the target when a consistent distractor color was present than when it was absent. Critically, these task-irrelevant learned distractor rejection effects were robust despite strong target guidance by an orthogonal search dimension. These findings corroborate recent demonstrations of learned distractor rejection during strong target guidance, indicating that learned distractor rejection and target guidance can operate on separate feature dimensions.

Testing the underlying processes leading to learned distractor rejection: Learned oculomotor avoidance.

Target templates stored in visual memory guide visual attention toward behaviorally relevant target objects. Visual attention also is guided away from nontarget distractors by longer-term learning, a phenomenon termed "learned distractor rejection." Template guidance and learned distractor rejection can occur simultaneously to further increase search efficiency. However, the underlying processes guiding learned distractor rejection are unknown. In two visual search experiments employing eye-tracking, we tested between two plausible processes: proactive versus reactive attentional control. Participants searched through two-color, spatially unsegregated displays. Participants could guide attention by both target templates and consistent nontarget distractors. We observed fewer distractor fixations (including the first eye movement) and shorter distractor dwell times. The data supported a single mechanism of learned distractor rejection, whereby observers adopted a learned, proactive attentional control setting to avoid distraction whenever possible. Further, when distraction occurred, observers rapidly recovered. We term this proactive mechanism "learned oculomotor avoidance." The current study informs theories of visual attention by demonstrating the underlying processes leading to learned distractor suppression during strong target guidance.

Does hand position affect orienting when no action is required? An electrophysiological study.

Previous research has shown that attention can be biased to targets appearing near the hand that require action responses, arguing that attention to the hand facilitates upcoming action. It is unclear whether attention orients to non-targets near the hand not requiring responses. Using electroencephalography/event-related potentials (EEG/ERP), this study investigated whether hand position affected visual orienting to non-targets under conditions that manipulated the distribution of attention. We modified an attention paradigm in which stimuli were presented briefly and rapidly on either side of fixation; participants responded to infrequent targets (15%) but not standard non-targets and either a hand or a block was placed next to one stimulus location. In Experiment 1, attention was distributed across left and right stimulus locations to determine whether P1 or N1 ERP amplitudes to non-target standards were differentially influenced by hand location. In Experiment 2, attention was narrowed to only one stimulus location to determine whether attentional focus affected orienting to non-target locations near the hand. When attention was distributed across both stimulus locations, the hand increased overall N1 amplitudes relative to the block but not selectively to stimuli appearing near the hand. However, when attention was focused on one location, amplitudes were affected by the location of attentional focus and the stimulus, but not by hand or block location. Thus, hand position appears to contribute only a non-location-specific input to standards during visual orienting, but only in cases when attention is distributed across stimulus locations.

Learned distractor rejection in the face of strong target guidance.

Visual attention is guided toward behaviorally relevant objects by target "templates" stored in visual memory. Visual attention also is guided away from nontarget distractors by learned distractor rejection. In a series of 5 visual search experiments, we asked if learned distractor rejection operated while attention was simultaneously guided by a target template. Participants performed a visual search in 2-color, spatially unsegregated displays where we manipulated attentional guidance by both target templates and consistent nontarget distractors. We observed faster mean response times to the target when a consistent nontarget distractor was present than when it was absent-the hallmark of learned distractor rejection-despite the use of strong target guidance. Learned distractor rejection indeed operates alongside guidance from a target template, indicating that theories of visual attention should incorporate guidance by both target templates and learned nontargets. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Feature-based statistical regularities of distractors modulate attentional capture.

Ignoring salient distracting information is paramount to efficiently guiding attention during visual search. Learning to reject or suppress these strong sources of distraction leads to more effective visual search for targets. Participants can learn to overcome salient distractors if given reliable search regularities. If salient distractors appear in 1 location more frequently than any other, the visual system can use this environmental regularity to reduce attentional capture at the more frequent location (Wang & Theeuwes, 2018). We asked if reduced attentional capture is limited to location-based regularities, or, if the visual attentional system is configured to use feature-based regularities in reducing attentional capture as well. In 4 experiments examining attentional capture by task-irrelevant color singletons, participants searched for a shape singleton target among homogenously colored distractors. Critically, on a proportion of trials, a salient, color singleton distractor was presented. Color singleton distractors that appeared at a frequent location captured attention less than color singleton distractors that appeared at infrequent locations, replicating previous findings. In subsequent experiments we manipulated the frequency of the colors of the color singleton distractors and observed robust increases in capture based on color feature regularities. Despite strong location information, we observed reliable attentional capture attenuation by frequently presented distractor colors. Our results suggest that attentional capture is attenuated by both location and feature information. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Learned and cued distractor rejection for multiple features in visual search.

Ignoring distracting information is critical for effective visual search. When individuals are cued to ignore a stimulus, they first attend the to-be-ignored stimulus before learning to reject it. Individuals can learn to overcome the initial distraction produced by the explicit cues, although this cued distractor rejection appears for only one distractor feature. Multiple distractor colors cannot be rejected effectively, even with extensive experience. We asked if this apparent limit on distractor rejection was caused by a restriction on the number of different features (i.e., colors) that could be learned and rejected as distractors. To explore this potential capacity limitation, we asked if attention can learn to reject the smallest possible number of multiple distractors, namely, two. In four experiments examining cued distractor rejection, individuals searched through heterogeneously colored arrays containing reliable, non-target color information. In Experiments 1 and 2, we explicitly cued individuals with which of two colors (both colors in Experiment 1 or one color in Experiment 2) could be safely ignored. Cued distractors were not reliably rejected, replicating previous findings. Additionally, in Experiment 2, we presented a to-be-ignored color without explicit cues and we found that these "uncued" distractors were reliably rejected. In Experiments 3 and 4, we presented the to-be-ignored color information without explicit cues; individuals learned to reliably ignore multiple distractor colors without explicit cueing. These results suggest that learned distractor rejection is better suited to experience-driven learning than explicitly cued distractor learning: Explicit cueing reliably interferes with learned distractor rejection.

Rejecting salient distractors: Generalization from experience.

Distraction impairs performance of many important, everyday tasks. Attentional control limits distraction by preferentially selecting important items for limited-capacity cognitive operations. Research in attentional control has typically investigated the degree to which selection of items is stimulus-driven versus goal-driven. Recent work finds that when observers initially learn a task, the selection is based on stimulus-driven factors, but through experience, goal-driven factors have an increasing influence. The modulation of selection by goals has been studied within the paradigm of learned distractor rejection, in which experience over a sequence of trials enables individuals eventually to ignore a perceptually salient distractor. The experiments presented examine whether observers can generalize learned distractor rejection to novel distractors. Observers searched for a target and ignored a salient color-singleton distractor that appeared in half of the trials. In Experiment 1, observers who learned distractor rejection in a variable environment rejected a novel distractor more effectively than observers who learned distractor rejection in a less variable, homogeneous environment, demonstrating that variable, heterogeneous stimulus environments encourage generalizable learned distractor rejection. Experiments 2 and 3 investigated the time course of learned distractor rejection across the experiment and found that after experiencing four color-singleton distractors in different blocks, observers could effectively reject subsequent novel color-singleton distractors. These results suggest that the optimization of attentional control to the task environment can be interpreted as a form of learning, demonstrating experience's critical role in attentional control.

Active Listening Delays Attentional Disengagement and Saccadic Eye Movements.

Successful goal-directed visual behavior depends on efficient disengagement of attention. Attention must be withdrawn from its current focus before being redeployed to a new object or internal process. Previous research has demonstrated that occupying cognitive processes with a secondary cellular phone conversation impairs attentional functioning and driving behavior. For example, attentional processing is significantly impacted by concurrent cell phone use, resulting in decreased explicit memory for on-road information. Here, we examined the impact of a critical component of cell-phone use-active listening-on the effectiveness of attentional disengagement. In the gap task-a saccadic manipulation of attentional disengagement-we measured saccade latencies while participants performed a secondary active listening task. Saccadic latencies significantly increased under an active listening load only when attention needed to be disengaged, indicating that active listening delays a disengagement operation. Simple dual-task interference did not account for the observed results. Rather, active cognitive engagement is required for measurable disengagement slowing to be observed. These results have implications for investigations of attention, gaze behavior, and distracted driving. Secondary tasks such as active listening or cell-phone conversations can have wide-ranging impacts on cognitive functioning, potentially impairing relatively elementary operations of attentional function, including disengagement.

Goal-directed attentional selection: Limitations from input variables, not imprecision.

When searching for a target object in a cluttered scene, the currently attended object is typically matched against a target template, a memory representation of the object being actively searched for. To determine if the currently attended item is the target requires a high degree of similarity to the template; any imprecision would make it difficult to distinguish between targets and visually similar nontargets. Thus, for attention to be efficient in finding targets requires the target template to be highly precise. Initial research on the precision of the target template suggested that the template was a highly precise depiction of the target object. In contrast, more recent findings suggested an imprecise template, demonstrating that participants were inaccurate in detecting a target when it appeared among visually similar distractors. In the current experiments, we demonstrate that visually similar distractors can hinder attentional selection because of limitations in selection and masking, not because of template imprecision. We conclude that the target template can be highly precise yet performance limited by factors not related to the target template itself. (PsycINFO Database Record

Stimulus recognition occurs under high perceptual load: Evidence from correlated flankers.

A dominant account of selective attention, perceptual load theory, proposes that when attentional resources are exhausted, task-irrelevant information receives little attention and goes unrecognized. However, the flanker effect-typically used to assay stimulus identification-requires an arbitrary mapping between a stimulus and a response. We looked for failures of flanker identification by using a more-sensitive measure that does not require arbitrary stimulus-response mappings: the correlated flankers effect. We found that flanking items that were task-irrelevant but that correlated with target identity produced a correlated flanker effect. Participants were faster on trials in which the irrelevant flanker had previously correlated with the target than when it did not. Of importance, this correlated flanker effect appeared regardless of perceptual load, occurring even in high-load displays that should have abolished flanker identification. Findings from a standard flanker task replicated the basic perceptual load effect, with flankers not affecting response times under high perceptual load. Our results indicate that task-irrelevant information can be processed to a high level (identification), even under high perceptual load. This challenges a strong account of high perceptual load effects that hypothesizes complete failures of stimulus identification under high perceptual load. (PsycINFO Database Record

The Relationship between Sitting and the Use of Symmetry As a Cue to Figure-Ground Assignment in 6.5-Month-Old Infants.

Two experiments examined the relationship between emerging sitting ability and sensitivity to symmetry as a cue to figure-ground (FG) assignment in 6.5-month-old infants (N = 80). In each experiment, infants who could sit unassisted (as indicated by parental report in Experiment 1 and by an in-lab assessment in Experiment 2) exhibited sensitivity to symmetry as a cue to FG assignment, whereas non-sitting infants did not. Experiment 2 further revealed that sensitivity to this cue is not related to general cognitive abilities as indexed using a non-related visual habituation task. Results demonstrate an important relationship between motor development and visual perception and further suggest that the achievement of important motor milestones such as stable sitting may be related to qualitative changes in sensitivity to monocular depth assignment cues such as symmetry.

Funny money: the attentional role of monetary feedback detached from expected value.

Stimuli associated with monetary reward can become powerful cues that effectively capture visual attention. We examined whether such value-driven attentional capture can be induced with monetary feedback in the absence of an expected cash payout. To this end, we implemented images of U.S. dollar bills as reward feedback. Participants knew in advance that they would not receive any money based on their performance. Our reward stimuli-$5 and $20 bill images-were thus dissociated from any practical utility. Strikingly, we observed a reliable attentional capture effect for the mere images of bills. Moreover, this finding generalized to Monopoly money. In two control experiments, we found no evidence in favor of nominal or symbolic monetary value. Hence, we claim that bill images are special monetary representations, such that there are strong associations between the defining visual features of bills and reward, probably due to a lifelong learning history. Together, we show that the motivation to earn cash plays a minor role when it comes to monetary rewards, while bill-defining visual features seem to be sufficient. These findings have the potential to influence human factor applications, such as gamification, and can be extended to novel value systems, such as the electronic cash Bitcoin being developed for use in mobile banking. Finally, our procedure represents a proof of concept on how images of money can be used to conserve expenditures in the experimental context.

The time-limited visual statistician.

The visual system can calculate summary statistics over time. For example, the multiple frames of a movie showing a dynamically changing disk can be collapsed to form a single representation of that disk's mean size. Summary representations of dynamic information may engage online updating processes that establish a running average of the mean by continuously adjusting the persisting representation of the average in tandem with the arrival of incoming information. Alternatively, summary representations may involve subsampling strategies that reflect limitations in the degree to which the visual system can integrate information over time. Observers watched movies of a disk that changed size smoothly at different rates and then reported the disk's average size by adjusting the diameter of a response disk. Critically, the movie varied in duration. Size estimates depended on the duration of the movie. They were constant and fairly accurate for movie durations up to approximately 600 ms, at which point accuracy decreased with increasing duration to imprecise levels by about 1,000 ms. Summary statistics established over time are unlikely to be updated continuously and may instead be restricted by subsampling processes, such as limited temporal windows of integration. (PsycINFO Database Record

Enhanced spatial resolution on figures versus grounds.

Much is known about the cues that determine figure-ground assignment, but less is known about the consequences of figure-ground assignment on later visual processing. Previous work has demonstrated that regions assigned figural status are subjectively more shape-like and salient than background regions. The increase in subjective salience of figural regions could be caused by a number of processes, one of which may be enhanced perceptual processing (e.g., an enhanced neural representation) of figures relative to grounds. We explored this hypothesis by having observers perform a perceptually demanding spatial resolution task in which targets appeared on either figure or ground regions. To rule out a purely attentional account of figural salience, observers discriminated targets on the basis of a region's color (red or green), which was equally likely to define the figure or the ground. The results of our experiments showed that targets appearing on figures were discriminated more accurately than those appearing in ground regions. In addition, targets appearing on figures were discriminated better than those presented in regions considered figurally neutral, but targets appearing within ground regions were discriminated more poorly than those appearing in figurally neutral regions. Taken together, our findings suggest that when two regions share a contour, regions assigned as figure are perceptually enhanced, whereas regions assigned as ground are perceptually suppressed.

Hand position biases processing toward task irrelevant flankers.

An unresolved issue in describing the impact of hand position on visual processing is whether near hand perceptual differences occur automatically or in a strategic and task-dependent fashion. A number of recent studies have demonstrated that the area in the graspable space of the hands is processed differently, and often preferentially, compared with areas distant from the hands (Abrams, Davoli, Du, Knapp, & Paull, 2008; Gozli, West, & Pratt, 2012; Reed, Grubb, & Steele, 2006). However, it is unclear whether the near-hand bias is automatic, or because of a strategic prioritization of search at near-hand locations. In the current studies, we used a flanker task, which did not require search for the target, to differentiate between these 2 alternatives. The task included 1 critical distractor that was either in the graspable space of a hand or on the opposite side of the screen. This critical distractor was either congruent or incongruent with the correct response. Our results indicate an impact of distractor congruency only when the critical distractor was presented in near-hand space. The congruency of distractors opposite the hand had no impact on response times. Further, we find that the near-hand effect is dependent on the inclusion of congruent flankers. These findings demonstrate that the allocation of preferential processing is conditionally automatic when near-hand locations can contain beneficial information, and absent when these locations contain only interfering and neutral information. (PsycINFO Database Record

A dynamic neural field model of temporal order judgments.

Temporal ordering of events is biased, or influenced, by perceptual organization-figure-ground organization-and by spatial attention. For example, within a region assigned figural status or at an attended location, onset events are processed earlier (Lester, Hecht, & Vecera, 2009; Shore, Spence, & Klein, 2001), and offset events are processed for longer durations (Hecht & Vecera, 2011; Rolke, Ulrich, & Bausenhart, 2006). Here, we present an extension of a dynamic field model of change detection (Johnson, Spencer, Luck, & Schöner, 2009; Johnson, Spencer, & Schöner, 2009) that accounts for both the onset and offset performance for figural and attended regions. The model posits that neural populations processing the figure are more active, resulting in a peak of activation that quickly builds toward a detection threshold when the onset of a target is presented. This same enhanced activation for some neural populations is maintained when a present target is removed, creating delays in the perception of the target's offset. We discuss the broader implications of this model, including insights regarding how neural activation can be generated in response to the disappearance of information.

Selection of multiple cued items is possible during visual short-term memory maintenance.

Recent neuroimaging studies suggest that maintenance of a selected object feature held in visual short-term/working memory (VSTM/VWM) is supported by the same neural mechanisms that encode the sensory information. If VSTM operates by retaining "reasonable copies" of scenes constructed during sensory processing (Serences, Ester, Vogel, & Awh, 2009, p. 207, the sensory recruitment hypothesis), then attention should be able to select multiple items represented in VSTM as long as the number of these attended items does not exceed the typical VSTM capacity. It is well known that attention can select at least two noncontiguous locations at the same time during sensory processing. However, empirical reports from the studies that examined this possibility are inconsistent. In the present study, we demonstrate that (1) attention can indeed select more than a single item during VSTM maintenance when observers are asked to recognize a set of items in the manner that these items were originally attended, and (2) attention can select multiple cued items regardless of whether these items are perceptually organized into a single group (contiguous locations) or not (noncontiguous locations). The results also replicate and extend the recent finding that selective attention that operates during VSTM maintenance is sensitive to the observers' goal and motivation to use the cueing information.

Value-driven attentional capture in adolescence.

Adolescence has been characterized as a period of both opportunity and vulnerability. Numerous clinical conditions, including substance-use disorders, often emerge during adolescence. These maladaptive behaviors have been linked to problems with cognitive control, yet few studies have investigated how rewards differentially modulate attentional processes in adolescents versus adults. Here, we trained adults and adolescents on a visual task to establish stimulus-reward associations. Later, we assessed learning in an extinction task in which previously rewarded stimuli periodically appeared as distractors. Both age groups initially demonstrated value-driven attentional capture; however, the effect persisted longer in adolescents than in adults. The results could not be explained by developmental differences in visual working memory. Given the importance of attentional control to daily behaviors and clinical conditions such as attention-deficit/hyperactivity disorder, these results reveal that cognitive control failures in adolescence may be linked to a value-based attentional-capture effect.

Differential effect of one versus two hands on visual processing.

Hand position in the visual field influences performance in several visual tasks. Recent theoretical accounts have proposed that hand position either (a) influences the allocation of spatial attention, or (b) biases processing toward the magnocellular visual pathway. Comparing these accounts is difficult as some studies manipulate the distance of one hand in the visual field while others vary the distance of both hands, and it is unclear whether single and dual hand manipulations have the same impact on perception. We ask if hand position affects the spatial distribution of attention, with a broader distribution of attention when both hands are near a visual display and a narrower distribution when one hand is near a display. We examined the effects of four hand positions near the screen (left hand, right hand, both hands, no hands) on both temporal and spatial discrimination tasks. Placing two hands near the display compared to two hands distant resulted in improved sensitivity for the temporal task and reduced sensitivity in the spatial task, replicating previous results. However, the single hand manipulations showed the opposite pattern of results. Together these results suggest that visual attention is focused on the graspable space for a single hand, and expanded when two hands frame an area of the visual field.

Visual statistical learning can drive object-based attentional selection.

Recent work on statistical learning has demonstrated that environmental regularities can influence aspects of perception, such as familiarity judgments. Here, we ask if statistical co-occurrences accumulated from visual statistical learning could form objects that serve as the units of attention (i.e., object-based attention). Experiment 1 demonstrated that, after observers first viewed pairs of shapes that co-occurred in particular spatial relationships, they were able to recognize the co-occurring pairs, and were faster to discriminate two targets when they appeared within a learned pair ("object") than when the targets appeared between learned pairs, demonstrating an equivalent of an object-based attention effect. Experiment 2 replicated the results of Experiment 1 using a different set of shape pairs, and revealed a negative association between the attention effect and familiarity judgments of the co-occurred pairs. Experiment 3 reports three control experiments that validated the task procedure and ruled out alternative accounts.