Rapid and selective updating of the target template in visual search.

Frequent target stimuli are detected more rapidly than infrequent ones. Here, we examined whether the frequency effect reflected durable attentional biases toward frequent target features, and whether the effect was confined to featural properties that defined the target. Participants searched for two specific target colors among distractors of heterogeneous colors and reported the line orientation of the target. The target was more often in one specific feature (e.g., a specific color or a specific orientation) than another in a training phase. This frequency difference was removed or reversed in a testing phase. Experiments 1 and 2 showed that when frequency differences were introduced to the target's defining feature, participants more rapidly found the high-frequency target than the low-frequency target. However, changes in attention were not durable-the search advantage vanished immediately when the frequency differences were removed. Experiments 3-5 showed that only featural properties that defined the target facilitated search of the more frequent feature. Features that did not define the target, such as the target feature that participants reported, sped up response but did not facilitate search. These data showed that when searching for multiple targets in a feature search task, people selectively and rapidly adapt to the frequency in the target's defining feature.

Changing viewer perspectives reveals constraints to implicit visual statistical learning.

Statistical learning-learning environmental regularities to guide behavior-likely plays an important role in natural human behavior. One potential use is in search for valuable items. Because visual statistical learning can be acquired quickly and without intention or awareness, it could optimize search and thereby conserve energy. For this to be true, however, visual statistical learning needs to be viewpoint invariant, facilitating search even when people walk around. To test whether implicit visual statistical learning of spatial information is viewpoint independent, we asked participants to perform a visual search task from variable locations around a monitor placed flat on a stand. Unbeknownst to participants, the target was more often in some locations than others. In contrast to previous research on stationary observers, visual statistical learning failed to produce a search advantage for targets in high-probable regions that were stable within the environment but variable relative to the viewer. This failure was observed even when conditions for spatial updating were optimized. However, learning was successful when the rich locations were referenced relative to the viewer. We conclude that changing viewer perspective disrupts implicit learning of the target's location probability. This form of learning shows limited integration with spatial updating or spatiotopic representations.

Redundancy gains in retinotopic cortex.

It is widely claimed that interactions among simultaneously presented visual stimuli are suppressive and that these interactions primarily occur when stimuli fall within the same receptive field (Desimone and Duncan 1995). Here, we show evidence for a novel form of interaction between simultaneously presented but distant stimuli that does not fit either pattern. To examine interactions between simultaneously presented stimuli, we measure the response to a single stimulus as a function of whether or not other stimuli are also presented simultaneously, and we further ask how the response to a given stimulus is affected by whether the simultaneously present stimuli are identical or different from each other. Our method reveals a new phenomenon of "redundancy gain:" the visual response to a stimulus is higher when accompanied by identical stimuli than when that stimulus is presented alone, even though the stimuli are displayed in separate visual quadrants. This pattern is observed throughout the visual hierarchy, including V1 and V2, and we show that it is distinct from the well-known simultaneous suppression effect (Kastner et al. 1998). We propose that the redundancy gain in early retinotopic cortex results from feedback from higher visual areas and may underlie perceptual averaging and other ensemble coding phenomena observed behaviorally.

Body and head tilt reveals multiple frames of reference for spatial attention.

Most modern theories of spatial attention suggest that it is based on a maplike representation that prioritizes information in some spatial locations over others. However, movement through space changes the relationship between what is "out there" and a person's viewpoint. Does spatial attention move with the viewer, or does it stay in environmental locations? Several recent psychophysical and neuroscience studies have attempted to address this question by probing attention following saccadic eye movements. The alignment of the head and body to the external environment in these studies, however, makes it impossible to determine whether attention is based on the viewer's location in space or on the external environment. The current study therefore introduces a head and/or body tilt through the vertical plane to dissociate viewer-centered from environment-centered representations. Participants first acquired a long-lasting attentional bias to a region of the search display that was likely to contain a target. They then tilted their head or body, and the location of the spatial bias was evaluated. The results suggest that attention has both a viewer-centered component that rotates with the viewer's head and an environment-centered component that is tied to environmental locations.

Visual search and location probability learning from variable perspectives.

Do moving observers code attended locations relative to the external world or relative to themselves? To address this question we asked participants to conduct visual search on a tabletop. The search target was more likely to occur in some locations than others. Participants walked to different sides of the table from trial to trial, changing their perspective. The high-probability locations were stable on the tabletop but variable relative to the viewer. When participants were informed of the high-probability locations, search was faster when the target was in those locations, demonstrating probability cuing. However, in the absence of explicit instructions and awareness, participants failed to acquire an attentional bias toward the high-probability locations even when the search items were displayed over an invariant natural scene. Additional experiments showed that locomotion did not interfere with incidental learning, but the lack of a consistent perspective prevented participants from acquiring probability cuing incidentally. We conclude that spatial biases toward target-rich locations are directed by two mechanisms: incidental learning and goal-driven attention. Incidental learning codes attended locations in a viewer-centered reference frame and is not updated with viewer movement. Goal-driven attention can be deployed to prioritize an environment-rich region.

Selection of events in time enhances activity throughout early visual cortex.

Temporal selection poses unique challenges to the perceptual system. Selection is needed to protect goal-relevant stimuli from interference from new sensory input. In addition, contextual information that occurs at the same time as goal-relevant stimuli may be critical for learning. Using fMRI, we characterized how visual cortical regions respond to the temporal selection of auditory and visual stimuli. Critically, we focused on brain regions that are not involved in processing the target itself. Participants pressed a button when they heard a prespecified target tone and did not respond to other tones. Although more attention was directed to auditory input when the target tone was selected, activity in primary visual cortex increased more after target tones than after distractor tones. In contrast to spatial attention, this effect was larger in V1 than in V2 and V3. It was present in regions not typically involved in representing the target stimulus. Additional experiments demonstrated that these effects were not due to multimodal processing, rare targets, or motor responses to the targets. Thus temporal selection of behaviorally relevant stimuli enhances, rather than reduces, activity in perceptual regions involved in processing other information.

"Guidance of spatial attention by incidental learning and endogenous cuing": Retraction.

Reports the retraction of "Guidance of spatial attention by incidental learning and endogenous cuing" by Yuhong V. Jiang, Khena M. Swallow and Gail M. Rosenbaum (Journal of Experimental Psychology: Human Perception and Performance, 2013[Feb], Vol 39[1], 285-297). The retraction is at the request of the authors. There was an unintentional error in the MATLAB experimental script used for Experiment 5 that caused one experimental condition to be incorrectly recorded in the data files. The authors confirmed that the MATLAB scripts used for Experiments 1 and 2 did not contain any errors and the findings and conclusions remain valid. However, for Experiments 3 and 4, the programming error led to two issues: (a) one variable was incorrectly written to the data files, and (b) the actual number of trials per condition during the training phase was unbalanced. To ensure that the scientific record is adequately corrected, the authors have uploaded additional information, including the MATLAB scripts for all experiments, the reanalysis of the data from Experiments 3, 4, and 5, and the validation of Experiments 1 and 2, to this OSF repository: https://osf.io/k79j4/?view_only=2220d62d0bb643f9b4ca53 e7a6da872f. The first author of the paper, who programmed the MATLAB scripts, takes full responsibility for the error. The authors sincerely regret this error and apologize for its effects on the editors, reviewers, and the broader scientific community. All authors of the original article joined in the request for the retraction. (The following abstract of the original article appeared in record 2012-09470-001). Our visual system is highly sensitive to regularities in the environment. Locations that were important in one's previous experience are often prioritized during search, even though observers may not be aware of the learning. In this study we characterized the guidance of spatial attention by incidental learning of a target's spatial probability, and examined the interaction between endogenous cuing and probability cuing. Participants searched for a target (T) among distractors (Ls). The target was more often located in one region of the screen than in others. We found that search reaction time (RT) was faster when the target appeared in the high-frequency region rather than the low-frequency regions. This difference increased when there were more items on the display, suggesting that probability cuing guides spatial attention. Additional data indicated that on their own, probability cuing and endogenous cuing (e.g., a central arrow that predicted a target's location) were similarly effective at guiding attention. However, when both cues were presented at once, probability cuing was largely eliminated. Thus, although both incidental learning and endogenous cuing can effectively guide attention, endogenous cuing takes precedence over incidental learning. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Advancing Research on Medical Image Perception by Strengthening Multidisciplinary Collaboration.

Medical image interpretation is central to detecting, diagnosing, and staging cancer and many other disorders. At a time when medical imaging is being transformed by digital technologies and artificial intelligence, understanding the basic perceptual and cognitive processes underlying medical image interpretation is vital for increasing diagnosticians' accuracy and performance, improving patient outcomes, and reducing diagnostician burnout. Medical image perception remains substantially understudied. In September 2019, the National Cancer Institute convened a multidisciplinary panel of radiologists and pathologists together with researchers working in medical image perception and adjacent fields of cognition and perception for the "Cognition and Medical Image Perception Think Tank." The Think Tank's key objectives were to identify critical unsolved problems related to visual perception in pathology and radiology from the perspective of diagnosticians, discuss how these clinically relevant questions could be addressed through cognitive and perception research, identify barriers and solutions for transdisciplinary collaborations, define ways to elevate the profile of cognition and perception research within the medical image community, determine the greatest needs to advance medical image perception, and outline future goals and strategies to evaluate progress. The Think Tank emphasized diagnosticians' perspectives as the crucial starting point for medical image perception research, with diagnosticians describing their interpretation process and identifying perceptual and cognitive problems that arise. This article reports the deliberations of the Think Tank participants to address these objectives and highlight opportunities to expand research on medical image perception.

Location probability learning in 3-dimensional virtual search environments.

When a visual search target frequently appears in one target-rich region of space, participants learn to search there first, resulting in faster reaction time when the target appears there than when it appears elsewhere. Most research on this location probability learning (LPL) effect uses 2-dimensional (2D) search environments that are distinct from real-world search contexts, and the few studies on LPL in 3-dimensional (3D) contexts include complex visual cues or foraging tasks and therefore may not tap into the same habit-like learning mechanism as 2D LPL. The present study aimed to establish a baseline evaluation of LPL in controlled 3D search environments using virtual reality. The use of a virtual 3D search environment allowed us to compare LPL for information within a participant's initial field of view to LPL for information behind participants, outside of the initial field of view. Participants searched for a letter T on the ground among letter Ls in a large virtual space that was devoid of complex visual cues or landmarks. The T appeared in one target-rich quadrant of the floor space on half of the trials during the training phase. The target-rich quadrant appeared in front of half of the participants and behind the other half. LPL was considerably greater in the former condition than in the latter. This reveals an important constraint on LPL in real-world environments and indicates that consistent search patterns and consistent egocentric spatial coding are essential for this form of visual statistical learning in 3D environments.

Simulated central vision loss impairs implicit location probability learning.

Some eye diseases, especially macular degeneration, can cause central vision loss (CVL), impairing goal-driven guidance of attention. Does CVL also affect implicit, experience-driven attention? We investigated how simulated central scotomas affected young adults' ability to prioritize locations frequently containing visual search targets (location probability learning). Participants searched among distractor letter 'L's for a target 'T' that appeared more often in one screen quadrant than others. To dissociate potential impairments to statistical learning of target locations and attentional guidance, two experiments each included search with and without simulated scotomas. Experiment 1 successfully induced probability learning in a no-scotoma phase. When participants later searched both with and without simulated scotomas, they showed persistent, statistically equivalent spatial biases in both no-scotoma and scotoma search. Experiment 2 trained participants with a central scotoma. While Experiment 1's participants acquired probability learning regardless of their self-reported awareness of the target's location probability, in Experiment 2 only aware participants learned to bias attention to the high probability region. Similarly, learning with a scotoma affected search with no scotoma in aware but not unaware participants. Together, these results show that simulated central vision loss interferes with the acquisition of implicitly learned location probability learning, supporting a role of central vision in implicit spatial attentional biases.

Inferior parietal lobule supports decision making under uncertainty in humans.

The optimal responses for many decisions faced by humans are ill defined, yet we are able to choose well by associating choices with outcomes, and employing this information in decision making. Previous studies suggest that the parietal cortex is involved in "uncertain" decision making, yet uncertainty is confounded with increased difficulty and attention. Here we aim to dissociate the role of parietal cortex in decision making and attention. Using functional magnetic resonance imaging we measured brain activity while participants played a "matching-pennies" game. We found that the inferior parietal lobule is involved in decision making under uncertainty, showing higher activity when the decision was uncertain rather than certain and when humans were given trial-by-trial feedback on choice outcomes than when they were not. Crucially, increasing attentional load with secondary tasks reduced inferior parietal activity when decisions were made under uncertainty, suggesting that general attention does not drive its activation. This pattern was consistent for visual or auditory feedback, and for direct (symbols representing wins and losses) or indirect (only the opponent's choices were shown) feedback. It contrasted with results from medial superior frontal gyrus, which was driven primarily by increased attentional load. We suggest that decision making under uncertainty is dissociable from general attention in the brain.

The visual attractor illusion.

In many visual illusions, the perceived features of an object such as its size or orientation are influenced by nearby objects. In contrast, the presence of nearby, static objects often enhances the perceived spatial location of another object. Here we present a type of visual illusion in which the presence of a static object alters another object's perceived location. Participants localized the edge of a briefly presented and masked target object. Localization was accurate when the masked target was presented in isolation. However, when another nearby object was presented at the same time as the target, localization deviated toward the nearby object (the "attractor"). This "visual attractor illusion" was stronger when the attractor object was task-relevant rather than irrelevant and diminished as the experiment progressed, suggesting that it was modulated by attention. Visual transients also play an important role in the illusion, which depends on the sudden onset of the attractor object and backward masking of the target. We suggest that the brief appearance of an object (the attractor) distorts perceptual space and draws in the perceived location of a neighboring object. Alternatively, localization of a masked target may be weighted toward the position of a concurrently presented visual transient.

The yellow light: Predictability enhances background processing during behaviorally relevant events.

The attentional boost effect refers to the observation that when simultaneously performing a scene memory task and a target detection task, participants better remember scenes that appear at the same time as the detection target than scenes that coincide with distractors. The attentional boost effect is thought to result from a transient increase in attention during an acute behaviorally relevant event, resulting from a temporal orienting response. But can endogenous orienting to predictable targets trigger this response in the same manner as exogenous orienting to unpredictable targets? Until now, the attentional boost effect has only been tested under conditions in which the target's appearance was unpredictable. Because of the distinction between exogenous and endogenous orienting, target predictability could attenuate the attentional boost effect, or it could increase temporal orienting efficiency and enhance the effect. To test the attentional boost effect under predictable conditions, participants memorized scenes while responding to a target digit, 0, among a stream of digits appearing in the center of those scenes. In some blocks, the 0 predictably followed the digit sequence 3-2-1. In these predictable blocks, participants showed a robust attentional boost effect. This shows that both endogenous orienting to temporally predictable targets and exogenous orienting to unpredictable targets enhance concurrent task processing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Tell me what you saw: The usefulness of verbal descriptions for others.

Describing what one saw to another person is common in everyday experience, such as spatial navigation and crime investigations. Past studies have examined the effects of recounting on one's own memory, neglecting an important function of memory recall in social communication. Here we report surprisingly low utility of one's verbal descriptions for others, even when visual memory for the stimuli has high capacity. Participants described photographs of common objects they had seen to enable judges to identify the target object from a foil in the same basic-level category. When describing from perception, participants were able to provide useful descriptions, allowing judges to accurately identify the target objects 87% of the time. Judges' accuracy decreased to just 57% when participants provided descriptions from memory acquired minutes ago, and to near chance (51.8%) when the verbal descriptions were based on memory acquired 24 hours ago. Comparison of participants' own identification accuracy with judges' accuracy suggests the presence of a common source of errors. This finding suggests that recall and recognition of visual objects share common memory sources. In addition, the low utility of one's verbal descriptions constrains theories about the extension of one's memory to the external world and has implications for eyewitness identification and laws governing it.

A spatial bias toward highly rewarded locations is associated with awareness.

Mounting evidence suggests that monetary reward induces an incidentally learned selection bias toward highly rewarded features. It remains controversial, however, whether learning of reward regularities has similar effects on spatial attention. Here we ask whether spatial biases toward highly rewarded locations are learned implicitly, or are instead associated with explicit knowledge of reward structure. Participants completed a hybrid search and choice task involving multiple targets among multiple distractors. Targets garnered varying magnitudes of reward, and participants were instructed to search for targets and guess and click on the 1 that they thought would yield the highest reward. Unbeknownst to participants, 1 side of the display offered higher reward than the other. We measured the spatial bias for targets on the high-reward side of the screen and probed explicit awareness via a multiquestion interview. Participants who were aware of the reward structure (N = 48) showed a selection bias for targets appearing on the high-reward side of the screen. Contrary to previous findings, unaware participants (N = 24) showed only a significant central bias, despite spending just as much time on the task. The strong association between explicit awareness and reward-driven spatial attention in this paradigm suggests that instead of directly affecting the attentional priority map, probabilistic spatial reward learning more frequently affects attention indirectly by modulating task goals. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Effects of changing object identity on location working memory.

It is widely accepted that features and locations are represented independently in an initial stage of visual processing. But to what degree are they represented separately at a later stage, after objects enter visual working memory (VWM)? In one of her last studies on VWM, Treisman raised an open question about how people represent locations in VWM, suggesting that locations may be remembered independently of what occupies them. Using photographs of real-world objects, we tested the independence of location memory from object identity in a location change detection task. We introduced changes to object identities between the encoding and test arrays, but instructed participants to treat the objects as placeholders. Three experiments showed that location memory was disrupted when the placeholders changed shape or orientation. The disruption was more noticeable for elongated than for round placeholders and was comparable between real-world objects and rectangles of similar aspect ratio. These findings suggest that location representation is sensitive to the placeholders' geometric properties. Though they contradict the idea that objects are just placeholders in location working memory (WM), the findings support Treisman's proposal that the items in VWM are bound to the global configuration of the memory array.

Contextual cueing in preview search.

Frequently finding a target in the same location within a familiar context reduces search time, relative to search for objects appearing in novel contexts. This learned association between a context and a target location requires several blocks of training and has long-term effects. Short-term selection history also influences search, where previewing a subset of a search context shortly before the appearance of the target and remaining distractors speeds search. Here we explored the interactions between contextual cueing and preview benefit using a modified version of a paradigm from Hodsoll and Humphreys (Journal of Experimental Psychology: Human Perception and Performance, 31(6), 1346-1358, 2005). Participants searched for a T target among L distractors. Half of the distractors appeared 800 ms before the addition of the other distractors and the target. We independently manipulated the repetition of the previewed distractors and the newly added distractors. Though the previewed set never contained the target, repetition of either the previewed or the newly added context yielded contextual cueing, and the effect was greater when the previewed context repeated. Another experiment trained participants to associate the previewed context with a target location, then disrupted the association in a testing phase. This disruption eliminated contextual cueing, suggesting that learning of the previewed context was associative. These findings demonstrate an important interaction between distinct kinds of selection history effects.

Redundancy gain in visual search of simulated X-ray images.

Cancer diagnosis frequently relies on the interpretation of medical images such as chest X-rays and mammography. This process is error prone; misdiagnoses can reach a rate of 15% or higher. Of particular interest are false negatives-tumors that are present but missed. Previous research has identified several perceptual and attentional problems underlying inaccurate perception of these images. But how might these problems be reduced? The psychological literature has shown that presenting multiple, duplicate images can improve performance. Here we explored whether redundant image presentation can improve target detection in simulated X-ray images, by presenting four identical or similar images concurrently. Displays with redundant images, including duplicates of the same image, showed reduced false-negative rates, compared with displays with a single image. This effect held both when the target's prevalence rate was high and when it was low. Eye tracking showed that fixating on two or more images in the redundant condition speeded target detection and prolonged search, and that the latter effect was the key to reducing false negatives. The redundancy gain may result from both perceptual enhancement and an increase in the search quitting threshold.

Perceptual learning in the identification of lung cancer in chest radiographs.

Extensive research has shown that practice yields highly specific perceptual learning of simple visual properties such as orientation and contrast. Does this same learning characterize more complex perceptual skills? Here we investigated perceptual learning of complex medical images. Novices underwent training over four sessions to discriminate which of two chest radiographs contained a tumor and to indicate the location of the tumor. In training, one group received six repetitions of 30 normal/abnormal images, the other three repetitions of 60 normal/abnormal images. Groups were then tested on trained and novel images. To assess the nature of perceptual learning, test items were presented in three formats - the full image, the cutout of the tumor, or the background only. Performance improved across training sessions, and notably, the improvement transferred to the classification of novel images. Training with more repetitions on fewer images yielded comparable transfer to training with fewer repetitions on more images. Little transfer to novel images occurred when tested with just the cutout of the cancer region or just the background, but a larger cutout that included both the cancer region and some surrounding regions yielded good transfer. Perceptual learning contributes to the acquisition of expertise in cancer image perception.

Supercrowding: weakly masking a target expands the range of crowding.

Crowding is impairment of peripheral object identification by nearby objects. Critical spacing (the minimum target-flanker distance that does not produce crowding) scales with target eccentricity and is consistently reported as roughly equal to or less than 50% of target eccentricity (0.5e). This study demonstrates that crowding occurs far beyond the typical critical spacing when the target is weakly masked by a surrounding contour or backwards pattern mask. A target was presented at a peripheral location on every trial and participants reported its orientation. Flankers appeared at target-flanker distances of 0.3-0.7e, or were absent. The target was presented with or without a mask. When flankers were absent, the masks only mildly impaired performance. When flankers were present but the mask was absent, target identification was nearly perfect at wide target-flanker distances (0.5e-0.7e). However, when flankers were present and the target was masked, performance dropped significantly, even when target-flanker distances far exceeded the typical crowding range. This phenomenon ("supercrowding") shares critical features with standard crowding: flankers similar to the target impair performance more than dissimilar flankers, and the characteristic anisotropic profile of crowding is preserved. Supercrowding may reflect a general interaction between crowding and other forms of masking.