Visual Search Task Research Articles

Inhibitory tagging in the superior colliculus during visual search.

Inhibitory tagging is an important feature of many models of saccade target selection, in particular those that are based on the notion of a neural priority map. The superior colliculus (SC) has been suggested as a potential site of such a map, yet it is unknown whether inhibitory tagging is represented in the SC during visual search. In this study, we tested the hypothesis that SC neurons represent inhibitory tagging during search, as might be expected if they contribute to a priority map. To do so, we recorded the activity of SC neurons in a multisaccade visual-search task. On each trial, a single reward-bearing target was embedded in an array of physically identical, potentially reward-bearing targets and physically distinct, non-reward-bearing distractors. The task was to fixate the reward-bearing target. We found that, in the context of this task, the activity of many SC neurons was greater when their response field stimulus was a target than when it was a distractor and was reduced when it had been previously fixated relative to when it had not. Moreover, we found that the previous-fixation-related reduction of activity was larger for targets than for distractors and decreased with increasing time (or number of saccades) since fixation. Taken together, the results suggest that fixated stimuli are transiently inhibited in the SC during search, consistent with the notion that inhibitory tagging plays an important role in visual search and that SC neurons represent this inhibition as part of a priority map used for saccade target selection.NEW & NOTEWORTHY Searching a cluttered scene for an object of interest is a ubiquitous task in everyday life, which we often perform relatively quickly and efficiently. It has been suggested that to achieve such speed and efficiency an inhibitory-tagging mechanism inhibits saccades to objects in the scene once they have been searched and rejected. Here, we demonstrate that the superior colliculus represents this type of inhibition during search, consistent with its role in saccade target selection.

The PD Reflects Selection of Nontarget Locations, Not Distractor Suppression.

In visual search tasks, negative features provide information about stimuli that can be excluded from search. It has been shown that these negative features help participants to locate the target, possibly by attentional suppression of stimuli sharing the negative feature. Attentional suppression is assumed to be reflected in an event-related potential, the PD component. To provide a further test of these assumptions, we presented the color of the distractor at the start of a trial and asked participants to find the other colored stimulus in the subsequent search display. Consistent with attentional suppression, we observed a PD to a lateral distractor shown with a vertical target. However, the PD occurred in this condition only when target and distractor could also be on opposite sides of fixation. The effect of trial context on the PD suggests that the PD reflects a search strategy whereby participants select stimuli opposite to the distractor when trials with opposite placements occur during the experiment. Therefore, the PD to the distractor may in fact be an N2pc to the opposite stimulus, indicating that the distractor is not suppressed, but avoided by redirecting attentional selection to the opposite side.

Fluent Processing Amplifies Affective Judgments

Abstract: The importance of processing fluency in evaluative judgments has been repeatedly demonstrated across many domains such as liking, beauty, and truth. However, a clear picture of the nature of processing fluency has yet to emerge. Fluent processing has been suggested to form evaluative judgments in a hedonic nature, in which existing judgmental tendencies always shift in a positive direction. Alternatively, fluency has been proposed to amplify evaluative judgments bidirectionally. However, uncertainty remains regarding the influence of processing fluency on pre-existing judgmental tendencies. Specifically, the extent to which the effect of stimuli belonging to specific categories varies within an individual remains unclear. This study assessed the influence of fluent processing on two specific categories (cats/spiders) using a visual search task. Fluency was manipulated by the set size of the stimuli and presentation duration. Fluency intensified pre-existing judgmental tendencies in two divergent directions: The initially favored stimuli were liked more, while the initially unfavored ones were liked less when the processing of stimuli was fluent. There was a significant correlation between favored and unfavored stimuli in terms of the magnitude of the effect, and such effect was influenced by visual attention, suggesting that processing fluency goes beyond a hedonic and unidimensional nature.

Task-irrelevant threatening information is harder to ignore than other valences.

Emotionally salient objects activate the survival circuits of the brain and are given priority in cognitive processing, even at the cost of inhibiting ongoing activities. These circuits arouse and prepare the organism to take swift action when needed. Previous studies have suggested, however, that not all emotional dimensions are equally prioritized. Threatening stimuli may have greater prominence than other emotional categories. Thus, we sought to compare the effects that stimuli of varying emotions would have on orienting and executive attentional processing. We performed two experiments to broaden our understanding of the attentional consequences of threats through the monitoring of participants' eye movements. Participants were exposed to emotionally charged (threatening, nonthreatening negative, positive) and neutral pictures as task-irrelevant distractors while performing a primary visual search task (under conditions of varying cognitive load). Behavioural results showed that participants found the first target number more slowly when the distractor image was threatening, but overall task completion times were actually speeded in this condition (relative to other valences). Further, participants fixated on threatening distractor images earlier and observed them longer than other valences. Results were more pronounced when the primary task was harder. These biases were not evident for positive and nonthreatening images, presumably because participants were able to ignore them, providing further support to the contention that threatening stimuli hold greater prominence than other emotional categories. Together, our results are in line with previous studies suggesting that the processing of threatening stimuli is speeded, potentially because of differences in the brain circuits involved. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Eye movement evidence for the V1 Saliency Hypothesis and the Central-peripheral Dichotomy theory in an anomalous visual search task

Typically, searching for a target among uniformly tilted non-targets is easier when this target is perpendicular, rather than parallel, to the non-targets. The V1 Saliency Hypothesis (V1SH) – that V1 creates a saliency map to guide attention exogenously – predicts exactly the opposite in a special case: each target or non-target is a pair of equally-sized disks, a homo-pair of two disks of the same color, black or white, or a hetero-pair of two disks of the opposite color; the inter-disk displacement defines its orientation. This prediction – parallel advantage – was supported by the finding that parallel targets require shorter reaction times (RTs) to report targets’ locations. Furthermore, it is stronger for targets further from the center of search images, as predicted by the Central-peripheral Dichotomy (CPD) theory entailing that saliency effects are stronger in peripheral than in central vision. However, the parallel advantage could arise from a shorter time required to recognize – rather than to shift attention to – the parallel target. By gaze tracking, the present study confirms that the parallel advantage is solely due to the RTs for the gaze to reach the target. Furthermore, when the gaze is sufficiently far from the target during search, saccade to a parallel, rather than perpendicular, target is more likely, demonstrating the Central-peripheral Dichotomy more directly. Parallel advantage is stronger among observers encouraged to let their search be guided by spontaneous gaze shifts, which are presumably guided by bottom-up saliency rather than top-down factors.

Nutritional labels and food intake regulation: The effect of external cues in the facilitation effect of food picture detection in visual search tasks

Nutritional labels and food intake regulation: The effect of external cues in the facilitation effect of food picture detection in visual search tasks

The benefit of making voluntary choices generalizes across multiple effectors.

It has been shown that cognitive performance could be improved by expressing volition (e.g., making voluntary choices), which necessarily involves the execution of action through a certain effector. However, it is unclear if the benefit of expressing volition can generalize across different effectors. In the present study, participants made a choice between two pictures either voluntarily or forcibly, and subsequently completed a visual search task with the chosen picture as a task-irrelevant background. The effector for choosing a picture could be the hand (pressing a key), foot (pedaling), mouth (commanding), or eye (gazing), whereas the effector for responding to the search target was always the hand. Results showed that participants responded faster and had a more liberal response criterion in the search task after a voluntary choice (vs. a forced choice). Importantly, the improved performance was observed regardless of which effector was used in making the choice, and regardless of whether the effector for making choices was the same as or different from the effector for responding to the search target. Eye-movement data for oculomotor choice showed that the main contributor to the facilitatory effect of voluntary choice was the post-search time in the visual search task (i.e., the time spent on processes after the target was found, such as response selection and execution). These results suggest that the expression of volition may involve the motor control system in which the effector-general, high-level processing of the goal of the voluntary action plays a key role.

Visual and cognitive processes contribute to age-related improvements in visual selective attention.

Children (N = 103, 4-9 years, 59 females, 84% White, c. 2019) completed visual processing, visual feature integration (color, luminance, motion), and visual search tasks. Contrast sensitivity and feature search improved with age similarly for luminance and color-defined targets. Incidental feature integration improved more with age for color-motion than luminance-motion. Individual differences in feature search ( = .11) and incidental feature integration ( = .06) mediated age-related changes in conjunction visual search, an index of visual selective attention. These findings suggest that visual selective attention is best conceptualized as a series of developmental trajectories, within an individual, that vary by an object's defining features. These data have implications for design of educational and interventional strategies intended to maximize attention for learning and memory.

Immediate and Differential Response to Emotional Stimuli Associated With Transcranial Direct Current Stimulation for Depression: A Visual-Search Task Pilot Study

ObjectivesWhen administered in repeated daily doses, transcranial direct current stimulation (tDCS) directed to the prefrontal cortex has cumulative efficacy for the treatment of depression. Depression can be marked by altered processing of emotionally salient information. An acute marker of response to tDCS may be measured as an immediate change in emotional information processing. Using an easily administered web-based task, we tested immediate changes in emotional information processing in acute response to tDCS in participants with and without depression. Materials and MethodsWe enrolled n = 21 women with mild-to-moderate depression and n = 20 controls without depression to complete a web-based visual search task before and after 30 minutes of tDCS directed to the prefrontal cortex. The timed task required participants to identify a target face among arrays showing sad, neutral, or mixed (distractor) expressions. ResultsAt baseline, as predicted, the participants with depression differed from those without in emotional processing speed (mean z score difference −0.66 ± 0.27, p = 0.022) and accuracy in identifying sad stimuli (error rate: 4.4% vs 1.8%, p = 0.039). In response to tDCS, the participants with depression became significantly faster on the distractor condition (pre- vs post-tDCS z scores: −0.45 ± 0.65 vs −0.85 ± 0.65, p = 0.009), suggesting a specific reduction in bias toward negative emotional information. In response to tDCS, the depressed group also had significant improvements in self-reported mood (increased happy, decreased sad and anxious mood). ConclusionsParticipants with depression vs those without were differentiated by their performance of the visual search task at baseline and in response to tDCS. Given that measurable effects on depression scales may require weeks of tDCS treatments, acute change in emotional information processing can serve as an easily obtainable marker of depression and its response to tDCS. Clinical Trial RegistrationThe Clinicaltrials.gov registration number for the study is NCT05188248.

Speakers of different languages remember visual scenes differently.

Language can have a powerful effect on how people experience events. Here, we examine how the languages people speak guide attention and influence what they remember from a visual scene. When hearing a word, listeners activate other similar-sounding words before settling on the correct target. We tested whether this linguistic coactivation during a visual search task changes memory for objects. Bilinguals and monolinguals remembered English competitor words that overlapped phonologically with a spoken English target better than control objects without name overlap. High Spanish proficiency also enhanced memory for Spanish competitors that overlapped across languages. We conclude that linguistic diversity partly accounts for differences in higher cognitive functions such as memory, with multilinguals providing a fertile ground for studying the interaction between language and cognition.

Alternating capture of attention by multiple visual working memory representations

Can we look for multiple objects simultaneously? Previous studies have proposed that the representation of an item in visual working memory (VWM) can bias the deployment of attention to memory-matching items in visual search. However, it is still controversial whether multiple VWM item representations are able to capture attention. In the present study, we adopted an eye-tracking technique to reveal this issue. In Experiment 1, we replicated Chen and Du’s Experiment 2 and adopted an eye-tracking technique to determine whether multiple VWM item representations are able to bias attention. In Chen and Du’s paradigm, the memory test was always followed by the search test, and the participants might intentionally prepare for the search task, which can affect the results of the research. Thus, in Experiment 2, we prevented participants from predicting the temporal occurrence of the visual search task by randomly conducting a search test or a memory test after memoranda. The findings of the present study suggested that only one working memory item at a time influences attention and multiple working memory items may affect attention through alternation.Protocol registrationThe stage 1 protocol for this Registered Report was accepted in principle on September 5, 2022. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/BE529.

Attentional suppression of weight-related distractors among females with weight dissatisfaction.

Although many studies have investigated attentional biases toward weight-related information among individuals with weight dissatisfaction, the mechanisms underlying the processing of task-irrelevant and spatial-irrelevant weight-related information as distractors remain unclear. Participants were assigned to groups according to their levels of weight dissatisfaction to address this question. Participants with high weight dissatisfaction (HWD) were assigned to the experimental group; those with low weight dissatisfaction (LWD) were assigned to a control group. By recording event-related potentials during a visual search task along the median vertical line, fatness-related/thinness-related/neutral words and scrambled strokes were presented horizontally in pairs as task-irrelevant distractors. The results showed that intact words facilitated fast attentional orienting compared to scrambled strokes, as revealed by the significant N2pc for all types of intact words for both the HWD and LWD groups. More importantly, only fatness- and thinness-related words elicited the evident PD in the HWD group, and the PD amplitudes were larger in the HWD group compared to the LWD group. These findings suggest that weight-related distractors were actively suppressed after initial attentional orienting among females with HWD. This reveals the mechanisms of attentional biases toward weight-related information among females with HWD and contributes to the model of the cognitive-behavioral theory of body image disturbance. These results may help enhance prevention and interventions for reducing weight dissatisfaction.

Distinct roles of theta and alpha oscillations in the process of contingent attentional capture.

Visual spatial attention can be captured by a salient color singleton that is contingent on the target feature. A previous study reported that theta (4-7 Hz) and alpha (8-14 Hz) oscillations were related to contingent attentional capture, but the corresponding attentional mechanisms of these oscillations remain unclear. In this study, we analyzed the electroencephalogram data of our previous study to investigate the roles of capture-related theta and alpha oscillation activities. Different from the previous study that used color-changed placeholders as irrelevant cues, the present study adopted abrupt onsets of color singleton cues which tend to elicit phase-locked neural activities. In Experiment 1, participants completed a peripheral visual search task in which spatially uninformative color singleton cues were inside the spatial attentional window and a central rapid serial visual presentation (RSVP) task in which the same cues were outside the spatial attentional window. In Experiment 2, participants completed a color RSVP task and a size RSVP task in which the peripheral color singleton cues were contingent and not contingent on target feature, respectively. In Experiment 1, spatially uninformative color singleton cues elicited lateralized theta activities when they were contingent on target feature, irrespective of whether they were inside or outside the spatial attentional window. In contrast, the same color singleton cues elicited alpha lateralization only when they were inside the spatial attentional window. In Experiment 2, we further found that theta lateralization vanished if the color singleton cues were not contingent on target feature. These results suggest distinct roles of theta and alpha oscillations in the process of contingent attentional capture initiated by abrupt onsets of singleton cues. Theta activities may reflect global enhancement of target feature, while alpha activities may be related to attentional engagement to spatially relevant singleton cues. These lateralized neural oscillations, together with the distractor-elicited N2pc component, might consist of multiple stages of attentional processes during contingent attentional capture.

The functional relevance of visuospatial processing speed across the lifespan

Visuospatial processing speed underlies several cognitive functions critical for successful completion of everyday tasks, including driving and walking. While it is widely accepted that visuospatial processing speed peaks in early adulthood, performance across the lifespan remains incompletely characterized. Additionally, there remains a lack of paradigms available to assess visuospatial processing speed in unsupervised web-based testing environments. To address these gaps, we developed a novel visuospatial processing speed (VIPS) task adapted from two tests sensitive to visuospatial processing speed declines in older adults, the Useful Field of View paradigm and the PERformance CEntered Portable Test. The VIPS task requires participants to make a central orientation discrimination and complete a simultaneous peripheral visual search task. Data were collected from 86 in-lab volunteers (18–30 years) to compare performance to traditional neuropsychological measures. Consistent with previous literature, performance on the novel VIPS task significantly correlated with measures of selective attention, executive functioning, visual speed, and working memory. An additional 4395 volunteers (12–62 years) were recruited on TestMyBrain.org to establish lifespan trajectories of visuospatial processing speed and associations with functional disability. VIPS task performance peaked in the early 20’s, and steadily decreased such that thresholds doubled in 60-year-olds relative to 20-year-olds (817 ms vs. 412 ms). VIPS task performance significantly correlated with self-reported cognitive functioning deficits broadly across the lifespan but was specifically related to mobility issues in middle-age. These findings have important implications for early detection of cognitive decline and provide insights into potential early intervention targets for younger and middle-aged adults.

Trade-off between search costs and accuracy in a visual and manual search task

Trade-off between search costs and accuracy in a visual and manual search task

Explicit attentional goals unlock implicit spatial statistical learning.

People can quickly learn spatial distributions of targets and direct attention to likely regions of targets. These implicitly learned spatial biases have been shown to be persistent, transferring to other similar visual search tasks. However, a persistent attentional bias is incompatible with frequently changing goals in our typical daily environment. We propose a flexible goal-specific probability cueing mechanism to address this discrepancy. We examined whether participants could learn and utilize target-specific spatial priority maps across five experiments (each N = 24). In Experiment 1, participants were faster to find the target at the target-specific high-probability location, in line with a goal-specific probability cueing effect. This demonstrated that separate spatial priorities derived from statistical learning can be flexibly activated based on the current goal. In Experiment 2, we ensured the results were not driven solely by intertrial priming. In Experiment 3, we ensured the results were driven by early attentional guidance effects. In Experiment 4, we extended our findings to a complex spatial distribution including four locations, supporting a sophisticated representation of target likelihood in the activated spatial priority maps. Finally, in Experiment 5, we confirmed that the effect was driven by the activation of an attentional template and not associative learning between the target cue and a spatial location. Our findings demonstrate a previously unrecognized mechanism for flexibility within statistical learning. The goal-specific probability cueing effect relies on coordination of feature-based and location-based attention, utilizing information that crosses traditional boundaries between top-down control and selection history. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Correlating Eye-Tracking Fixation Metrics and Neuropsychological Assessment after Ischemic Stroke.

Background and Objectives: Stroke survivors commonly experience cognitive deficits, which significantly impact their quality of life. Integrating modern technologies like eye tracking into cognitive assessments can provide objective and non-intrusive measurements. Materials and Methods: This study aimed to evaluate the cognitive and visual processing capabilities of stroke patients using eye-tracking metrics and psychological evaluations. A cohort of 84 ischemic stroke patients from the N-PEP-12 clinical study was selected for secondary analysis, based on the availability of eye-tracking data collected during a visual search task using an adapted Trail Making Test. Standardized cognitive assessments, including the Montreal Cognitive Assessment (MoCA) and digit span tasks, were also conducted. Results: Correlation analyses revealed some notable relationships between eye-tracking metrics and cognitive measures, such as a positive correlation between Symbol Search performance and the number of fixations. Anxiety levels were found to be positively correlated with first fixation duration, while longer first fixation durations were associated with poorer cognitive performance. However, most correlations were not statistically significant. Nonparametric ANOVA showed no significant differences in fixation metrics across the visits. Conclusions: These findings suggest a complex relationship between cognitive status, gaze fixation behavior, and psychological well-being in stroke patients. Further research with larger sample sizes and analysis of saccadic eye movements is needed to better understand these relationships and inform effective interventions for stroke rehabilitation.

Attentional selection is a sufficient cause for visual working memory interference.

Visual attention and visual working memory (VWM) are intertwined processes that allow navigation of the visual world. These systems can compete for highly limited cognitive resources, creating interference effects when both operate in tandem. Performing an attentional task while maintaining a VWM load often leads to a loss of memory information. These losses are seen even with very simple visual search tasks. Previous research has argued that this may be due to the attentional selection process, of choosing the target item out of surrounding nontarget items. Over two experiments, the current study disentangles the roles of search and selection in visual search and their influence on a retained VWM load. Experiment 1 revealed that, when search stimuli were relatively simple, target-absent searches (which did not require attentional selection) did not provoke memory interference, whereas target-present search did. In Experiment 2, the number of potential targets was varied in the search displays. In one condition, participants were required to select any one of the items displayed, requiring an attentional selection but no need to search for a specific item. Importantly, this condition led to memory interference to the same extent as a condition where a single target was presented among nontargets. Together, these results show that the process of attentional selection is a sufficient cause for interference with a concurrently maintained VWM load.

Mechanisms of Cognitive Change: Training Improves the Quality But Not the Quantity of Visual Working Memory Representations.

As of yet, visual working memory (WM) training has failed to yield consistent cognitive benefits to performance in untrained tasks, despite large improvements in trained tasks. Investigating the mechanisms underlying training effects can help explain these inconsistencies. In this pre-registered, pre-test/post-test online training study, we examined how training affects the quantity and quality of representations in visual WM using continuous-reproduction tasks. N = 64 young healthy adults were randomly assigned to an experimental group or an active control group to complete four training sessions of practce in an orientation-reproduction or a visual search task, respectively. We observed that, in the trained task, only the quality, but not the quantity, of visual WM representations significantly increased in the experimental group relative to the control group. These improvements did not generalise to untrained stimuli or paradigms. Therefore, our findings suggest that training gains are not driven by enhanced capacity. Instead, gains in the quality of visual WM representations that are tied to specific stimuli and paradigms may reflect enhanced efficiency in using the existing visual WM capacity.

Statistical learning facilitates the strategic use of attentional control

A growing body of research suggests that observers rely on a variety of suboptimal strategies when searching for objects. However, real-world environments contain a variety of statistical regularities that enable more efficient processing of information. In the present study, we examined whether statistical learning can influence the strategic use of attentional control using a modified version of the adaptive choice visual search task. Participants searched through an array of colored squares and identified a digit located within a red or blue target square. Each trial contained both a red and a blue target, and participants were free to choose which color to search for. On each trial, more squares were presented in one color than the other color. Thus, the optimal strategy was to search for the color with the fewest squares. Critically, one color was the optimal color on 75% of trials, while the other color was the optimal color on the remaining 25% of trials. Participants were faster to identify targets and made a larger proportion of optimal choices when the high-probability optimal color was optimal. Thus, statistical learning facilitated both search for the targets and the optimal choice of attentional control settings. These effects persisted when the color contingencies were equated, suggesting that these findings were not simply due to intertrial priming. Moreover, participants were not slower to identify targets when the high-probability optimal color appeared as a distractor, suggesting that these findings were not due to attentional capture by this color. Together, these findings suggest that statistical learning can facilitate the strategic use of attentional control by biasing which features observers choose to search for.