scholarly journals Feature distribution learning by passive exposure

2021 ◽  
Author(s):  
David Pascucci ◽  
Gizay Ceylan ◽  
Arni Kristjansson
Keyword(s):  
Visual Search ◽  
Response Times ◽  
Search Display ◽  
Perceptual System ◽  
Active Engagement ◽  
Target Feature ◽  
Initial Exposure ◽  
Passive Exposure ◽  
Distribution Shape ◽  
Exposure Stage

Humans can rapidly estimate the statistical properties of groups of stimuli, including their average and variability. But recent studies of so-called Feature Distribution Learning (FDL) have shown that observers can quickly learn even more complex aspects of feature distributions. In FDL, observers learn the full shape of a distribution of features in a set of distractor stimuli and use this information to improve visual search: response times (RT) are slowed if the target feature lies inside the previous distractor distribution, and the RT patterns closely reflect the distribution shape. FDL requires only a few trials and is markedly sensitive to different distribution types. It is unknown, however, whether our perceptual system encodes feature distributions automatically and by passive exposure, or whether this learning requires active engagement with the stimuli. In two experiments, we sought to answer this question. During an initial exposure stage, participants passively viewed a display of 36 lines that included one orientation singleton or no singletons. In the following search display, they had to find an oddly oriented target. The orientations of the lines were determined either by a Gaussian or a uniform distribution. We found evidence for FDL only when the passive trials contained an orientation singleton. Under these conditions, RT decreased as a function of the orientation distance between the target and the exposed distractor distribution. These results suggest that FDL can occur by passive exposure, but only if an orientation singleton appears during exposure to the distribution.

scholarly journals Temporal integration of feature probability distributions in working memory

2020 ◽  
Author(s):  
Sabrina Hansmann-Roth ◽  
Sóley Thorsteinsdóttir ◽  
Joy Geng ◽  
Arni Kristjansson
Keyword(s):  
Visual Search ◽  
Visual System ◽  
Uniform Distribution ◽  
Probability Distributions ◽  
Temporal Integration ◽  
Target Feature ◽  
Target Distribution ◽  
Distribution Shape ◽  
Complex Target ◽  
Feature Probability

Humans are surprisingly good at learning the characteristics of their visual environment. Recent studies have revealed that not only can the visual system learn repeated features of visual search distractors, but their actual probability distributions. Search times were determined by the frequency of distractor features over consecutive search trials. Distractor distributions involve many exemplars on each trial, but whether observers can learn distributions where only a single exemplar from the distribution is presented on each trial is unknown. Here, we investigated potential learning of probability distributions of single targets during visual search. Over blocks of trials observers searched for an oddly-colored target that was drawn from either a Gaussian or uniform distribution. Not only was search influenced by the repetition of a target feature but more interestingly also by the probability of that feature within trial blocks. The same search targets, coming from the extremes of the two distributions were found significantly slower during the blocks where the distractors were drawn from a Gaussian distribution than from a uniform distribution indicating that observers were sensitive to the target probability determined by the distribution shape. In Experiment 2 we replicated the effect using binned distributions and revealed the limitations of target distribution encoding by using a more complex target distribution. Our results demonstrate detailed internal representations of target feature distributions and that the visual system integrates probability distributions of target colors over surprisingly long trial sequences.

scholarly journals Simulated central vision loss does not impair implicit location probability learning when participants search through simple displays

2021 ◽  
Author(s):  
Douglas A Addleman ◽  
Vanessa G. Lee
Keyword(s):  
Visual Search ◽  
Spatial Attention ◽  
Vision Loss ◽  
Target Location ◽  
Response Times ◽  
Probability Learning ◽  
Search Display ◽  
Natural Scenes ◽  
Central Vision ◽  
Central Vision Loss

Central vision loss disrupts voluntary shifts of spatial attention during visual search. Recently, we reported that a simulated scotoma impaired implicit spatial attention towards regions likely to contain search targets. In that task, search items were overlaid on natural scenes. Because natural scenes can induce explicit awareness of learned biases leading to voluntary shifts of attention, here we used a search display with a blank background less likely to induce awareness of target location probabilities. Participants searched both with and without a simulated central scotoma: a training phase contained targets more often in one screen quadrant and a testing phase contained targets equally often in all quadrants. In Experiment 1, training used no scotoma, while testing alternated between blocks of scotoma and no-scotoma search. Experiment 2 training included the scotoma and testing again alternated between scotoma and no-scotoma search. Response times and saccadic behaviors in both experiments showed attentional biases towards the high-probability target quadrant during scotoma and no-scotoma search. Whereas simulated central vision loss impairs implicitly learned spatial attention in the context of natural scenes, our results show that this may not arise from impairments to the basic mechanisms of attentional learning indexed by visual search tasks without scenes.

scholarly journals Visual search behavior and performance in luggage screening: effects of time pressure, automation aid, and target expectancy

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Tobias Rieger ◽  
Lydia Heilmann ◽  
Dietrich Manzey
Keyword(s):  
Visual Search ◽  
Target Location ◽  
Time Pressure ◽  
Response Times ◽  
Search Behavior ◽  
High Time ◽  
Luggage Screening ◽  
Negative Effect ◽  
And Performance ◽  
Automated Support

AbstractVisual inspection of luggage using X-ray technology at airports is a time-sensitive task that is often supported by automated systems to increase performance and reduce workload. The present study evaluated how time pressure and automation support influence visual search behavior and performance in a simulated luggage screening task. Moreover, we also investigated how target expectancy (i.e., targets appearing in a target-often location or not) influenced performance and visual search behavior. We used a paradigm where participants used the mouse to uncover a portion of the screen which allowed us to track how much of the stimulus participants uncovered prior to their decision. Participants were randomly assigned to either a high (5-s time per trial) or a low (10-s time per trial) time-pressure condition. In half of the trials, participants were supported by an automated diagnostic aid (85% reliability) in deciding whether a threat item was present. Moreover, within each half, in target-present trials, targets appeared in a predictable location (i.e., 70% of targets appeared in the same quadrant of the image) to investigate effects of target expectancy. The results revealed better detection performance with low time pressure and faster response times with high time pressure. There was an overall negative effect of automation support because the automation was only moderately reliable. Participants also uncovered a smaller amount of the stimulus under high time pressure in target-absent trials. Target expectancy of target location improved accuracy, speed, and the amount of uncovered space needed for the search.Significance Statement Luggage screening is a safety–critical real-world visual search task which often has to be done under time pressure. The present research found that time pressure compromises performance and increases the risk to miss critical items even with automation support. Moreover, even highly reliable automated support may not improve performance if it does not exceed the manual capabilities of the human screener. Lastly, the present research also showed that heuristic search strategies (e.g., areas where targets appear more often) seem to guide attention also in luggage screening.

scholarly journals Neural Dynamics of Cognitive Control over Working Memory Capture of Attention

2019 ◽  
Vol 31 (7) ◽  
pp. 1079-1090 ◽  
Author(s):  
Peter S. Whitehead ◽  
Mathilde M. Ooi ◽  
Tobias Egner ◽  
Marty G. Woldorff
Keyword(s):  
Working Memory ◽  
Visual Search ◽  
Cognitive Control ◽  
Attentional Capture ◽  
Search Display ◽  
Neural Mechanisms ◽  
High Temporal Resolution ◽  
Control Mechanisms ◽  
Attentional Orienting ◽  
Behavioral Studies

The contents of working memory (WM) guide visual attention toward matching features, with visual search being faster when the target and a feature of an item held in WM spatially overlap (validly cued) than when they occur at different locations (invalidly cued). Recent behavioral studies have indicated that attentional capture by WM content can be modulated by cognitive control: When WM cues are reliably helpful to visual search (predictably valid), capture is enhanced, but when reliably detrimental (predictably invalid), capture is attenuated. The neural mechanisms underlying this effect are not well understood, however. Here, we leveraged the high temporal resolution of ERPs time-locked to the onset of the search display to determine how and at what processing stage cognitive control modulates the search process. We manipulated predictability by grouping trials into unpredictable (50% valid/invalid) and predictable (100% valid, 100% invalid) blocks. Behavioral results confirmed that predictability modulated WM-related capture. Comparison of ERPs to the search arrays showed that the N2pc, a posteriorly distributed signature of initial attentional orienting toward a lateralized target, was not impacted by target validity predictability. However, a longer latency, more anterior, lateralized effect—here, termed the “contralateral attention-related negativity”—was reduced under predictable conditions. This reduction interacted with validity, with substantially greater reduction for invalid than valid trials. These data suggest cognitive control over attentional capture by WM content does not affect the initial attentional-orienting process but can reduce the need to marshal later control mechanisms for processing relevant items in the visual world.

scholarly journals Color Can Shorten Breakthrough Times in Continuous Flash Suppression through Increased Salience and Task Relevance

Vision ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 13
Author(s):  
Christian Valuch
Keyword(s):  
Visual Search ◽  
Response Times ◽  
Top Down ◽  
Interocular Suppression ◽  
Continuous Flash Suppression ◽  
Task Relevance ◽  
Mediated Effects ◽  
Dominant Eye ◽  
Human Participants ◽  
And Task

Color can enhance the perception of relevant stimuli by increasing their salience and guiding visual search towards stimuli that match a task-relevant color. Using Continuous Flash Suppression (CFS), the current study investigated whether color facilitates the discrimination of targets that are difficult to perceive due to interocular suppression. Gabor patterns of two or four cycles per degree (cpd) were shown as targets to the non-dominant eye of human participants. CFS masks were presented at a rate of 10 Hz to the dominant eye, and participants had the task to report the target’s orientation as soon as they could discriminate it. The 2-cpd targets were robustly suppressed and resulted in much longer response times compared to 4-cpd targets. Moreover, only for 2-cpd targets, two color-related effects were evident. First, in trials where targets and CFS masks had different colors, targets were reported faster than in trials where targets and CFS masks had the same color. Second, targets with a known color, either cyan or yellow, were reported earlier than targets whose color was randomly cyan or yellow. The results suggest that the targets’ entry to consciousness may have been speeded by color-mediated effects relating to increased (bottom-up) salience and (top-down) task relevance.

scholarly journals Relative frequency of attribute relevance and response times in visual search

1974 ◽  
Vol 2 (3) ◽  
pp. 453-462 ◽  
Author(s):  
George C. Stone ◽  
Shirley C. Peeke
Keyword(s):  
Visual Search ◽  
Relative Frequency ◽  
Response Times

scholarly journals Inter-trial effects in priming of pop-out: Comparison of computational updating models

2021 ◽  
Vol 17 (9) ◽  
pp. e1009332
Author(s):  
Fredrik Allenmark ◽  
Ahu Gokce ◽  
Thomas Geyer ◽  
Artyom Zinchenko ◽  
Hermann J. Müller ◽  
...  
Keyword(s):  
Model Comparison ◽  
Response Times ◽  
Target Position ◽  
Preceding Trial ◽  
Target Color ◽  
Model Parameters ◽  
Target Feature ◽  
Modeling Framework ◽  
Trial Effect ◽  
Starting Point

In visual search tasks, repeating features or the position of the target results in faster response times. Such inter-trial ‘priming’ effects occur not just for repetitions from the immediately preceding trial but also from trials further back. A paradigm known to produce particularly long-lasting inter-trial effects–of the target-defining feature, target position, and response (feature)–is the ‘priming of pop-out’ (PoP) paradigm, which typically uses sparse search displays and random swapping across trials of target- and distractor-defining features. However, the mechanisms underlying these inter-trial effects are still not well understood. To address this, we applied a modeling framework combining an evidence accumulation (EA) model with different computational updating rules of the model parameters (i.e., the drift rate and starting point of EA) for different aspects of stimulus history, to data from a (previously published) PoP study that had revealed significant inter-trial effects from several trials back for repetitions of the target color, the target position, and (response-critical) target feature. By performing a systematic model comparison, we aimed to determine which EA model parameter and which updating rule for that parameter best accounts for each inter-trial effect and the associated n-back temporal profile. We found that, in general, our modeling framework could accurately predict the n-back temporal profiles. Further, target color- and position-based inter-trial effects were best understood as arising from redistribution of a limited-capacity weight resource which determines the EA rate. In contrast, response-based inter-trial effects were best explained by a bias of the starting point towards the response associated with a previous target; this bias appeared largely tied to the position of the target. These findings elucidate how our cognitive system continually tracks, and updates an internal predictive model of, a number of separable stimulus and response parameters in order to optimize task performance.

scholarly journals Passive exposure attenuates distraction during visual search.

2020 ◽  
Vol 149 (10) ◽  
pp. 1987-1995 ◽  
Author(s):  
Bo-Yeong Won ◽  
Joy J. Geng
Keyword(s):  
Visual Search ◽  
Passive Exposure

When visual search target is rare: overweighting or under weighting the probability?

2018 ◽  
Vol 62 (1) ◽  
pp. 1520-1524
Author(s):  
Hanshu Zhang ◽  
Joseph W. Houpt
Keyword(s):  
Visual Search ◽  
Search Task ◽  
Visual Search Task ◽  
Response Times ◽  
Threshold Model ◽  
Decision Makers ◽  
Target Presence ◽  
Model Assumption ◽  
Search Tasks ◽  
Low Prevalence

The prevalence of items in visual search may have substantial performance consequences. In laboratory visual search tasks in which the target is rare, viewers are likely to miss the target. A dual-threshold model proposed by Wolfe and Van Wert (2010) assumes that in the low prevalence condition, viewers shift their criteria resulting in more miss errors. However, from the prospective of prospect theory (Kahneman & Tversky, 1979), decision makers tend to overweight small probability. To explore how viewers subjectively weight the probability in the low prevalence visual search task, we compared viewers’ criteria with the optimal criteria by presenting different probability descriptions for a fixed prevalence rate. The data from this experiment indicated that target presence had an effect on viewers’ accuracy and response times but not probability descriptions. Viewers’ criteria under different probability descriptions were higher than optimal. These results are in accordance with the dual-threshold model assumption that viewers respond “target absent” more frequently than optimal, leading to more miss errors in the low prevalence condition.

scholarly journals The price of information: Increased inspection costs reduce the confirmation bias in visual search

2018 ◽  
Vol 71 (4) ◽  
pp. 832-849 ◽  
Author(s):  
Jason Rajsic ◽  
Daryl E. Wilson ◽  
Jay Pratt
Keyword(s):  
Visual Search ◽  
Low Cost ◽  
Confirmation Bias ◽  
Human Perception ◽  
Search Display ◽  
Guidance Strategies ◽  
Low Cost Strategy ◽  
Expected Benefits ◽  
And Performance ◽  
Fourth Experiment

In visual search, there is a confirmation bias such that attention is biased towards stimuli that match a target template, which has been attributed to covert costs of updating the templates that guide search [Rajsic, Wilson, & Pratt, 2015. Confirmation bias in visual search. Journal of Experimental Psychology: Human Perception and Performance. Advance online publication. doi:10.1037/xhp0000090]. In order to provide direct evidence for this speculation, the present study increased the cost of inspections in search by using gaze- and mouse-contingent searches, which restrict the manner in which information in search displays can be accrued, and incur additional motor costs (in the case of mouse-contingent searches). In a fourth experiment, we rhythmically mask elements in the search display to induce temporal inspection costs. Our results indicated that confirmation bias is indeed attenuated when inspection costs are increased. We conclude that confirmation bias results from the low-cost strategy of matching information to a single, concrete visual template, and that more sophisticated guidance strategies will be used when sufficiently beneficial. This demonstrates that search guidance itself comes at a cost, and that the form of guidance adopted in a given search depends on a comparison between guidance costs and the expected benefits of their implementation.

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