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

Author(s):  
Hanshu Zhang ◽  
Joseph W. Houpt

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.

Author(s):  
Scott M. Galster ◽  
Robert S. Bolia ◽  
Raja Parasuraman

A visual search paradigm was used to examine the effects of status information as well as decision-aiding automation in a target detection and processing task. Manual, information automation, and decision-aiding automation conditions were manipulated with the size of the distractor set. Participants were required to respond to the presence or absence of a target in a time-limited trial. In the information automation condition, status information regarding target presence was presented to the participant. The participants were informed that the information automation was not perfectly reliable. A significant detection performance improvement was observed in the information automation condition. This improvement was more marked in the conditions with the higher number of distractors. Additionally, response times were improved when the information automation cue was present. Effects of cue validity and incorrect responses are presented. Implications of the results and future studies are discussed.


Author(s):  
Nathan Messmer ◽  
Nathan Leggett ◽  
Melissa Prince ◽  
Jason S. McCarley

Gaze linking allows team members in a collaborative visual task to scan separate computer monitors simultaneously while their eye movements are tracked and projected onto each other’s displays. The present study explored the benefits of gaze linking to performance in unguided and guided visual search tasks. Participants completed either an unguided or guided serial search task as both independent and gaze-linked searchers. Although it produced shorter mean response times than independent search, gaze linked search was highly inefficient, and gaze linking did not differentially affect performance in guided and unguided groups. Results suggest that gaze linking is likely to be of little value in improving applied visual search.


2019 ◽  
Author(s):  
Cherie Zhou ◽  
Monicque M. Lorist ◽  
Sebastiaan Mathôt

AbstractDuring visual search, task-relevant representations in visual working memory (VWM), known as attentional templates, are assumed to guide attention. A current debate concerns whether only one (Single-Item-Template hypothesis, or SIT) or multiple (Multiple-Item-Template hypothesis, or MIT) items can serve as attentional templates simultaneously. The current study was designed to test these two hypotheses. Participants memorized two colors, prior to a visual-search task in which the target and the distractor could match or not match the colors held in VWM. Robust attentional guidance was observed when one of the memory colors was presented as the target (reduced response times [RTs] on target-match trials) or the distractor (increased RTs on distractor-match trials). We constructed two drift-diffusion models that implemented the MIT and SIT hypotheses, which are similar in their predictions about overall RTs, but differ in their predictions about RTs on individual trials. Critically, simulated RT distributions and error rates revealed a better match of the MIT hypothesis to the observed data than the SIT hypothesis. Taken together, our findings provide behavioral and computational evidence for the concurrent guidance of attention by multiple items in VWM.Significance statementTheories differ in how many items within visual working memory can guide attention at the same time. This question is difficult to address, because multiple- and single-item-template theories make very similar predictions about average response times. Here we use drift-diffusion modeling in addition to behavioral data, to model response times at an individual level. Crucially, we find that our model of the multiple-item-template theory predicts human behavior much better than our model of the single-item-template theory; that is, modeling of behavioral data provides compelling evidence for multiple attentional templates that are simultaneously active.


1981 ◽  
Vol 53 (2) ◽  
pp. 411-418
Author(s):  
Lance A. Portnoff ◽  
Jerome A. Yesavage ◽  
Mary B. Acker

Disturbances in attention are among the most frequent cognitive abnormalities in schizophrenia. Recent research has suggested that some schizophrenics have difficulty with visual tracking, which is suggestive of attentional deficits. To investigate differential visual-search performance by schizophrenics, 15 chronic undifferentiated and 15 paranoid schizophrenics were compared with 15 normals on two tests measuring visual search in a systematic and an unsystematic stimulus mode. Chronic schizophrenics showed difficulty with both kinds of visual-search tasks. In contrast, paranoids had only a deficit in the systematic visual-search task. Their ability for visual search in an unsystematized stimulus array was equivalent to that of normals. Although replication and cross-validation is needed to confirm these findings, it appears that the two tests of visual search may provide a useful ancillary method for differential diagnosis between these two types of schizophrenia.


Author(s):  
Michael F. Gorman ◽  
Donald L. Fisher

The fact that response times increase as one ages has long been established. Previously, a model of general slowing in the nonlexical domains has done a really good job of explaining the differences between older and younger adults. However, an alternative process-specific model has not been conclusively ruled out. This experiment tested general and process-specific models of slowing in the nonlexical domain using older and younger adults performing a visual search task. The task manipulated the presence of the target, the number of search items, and the structure of the display of the search items. It was found that a process-specific model explained significantly more of the variability than a general model of slowing. It was also discovered that the process most greatly affected was that of deciding to terminate a search when no target was present in the display.


1988 ◽  
Vol 32 (19) ◽  
pp. 1316-1319
Author(s):  
Daniel Workman ◽  
Donald L. Fisher

A new model of visual search is proposed. It is suggested that in searching for a target among distractors, there is some threshold level of similarity between the target and the distractors. When the similarity of the target to a given distractor is below this threshold the distractor can be quickly rejected. When the distractor is above the threshold level of similarity it will take additional time to reject the distractor. Several models of visual search, including threshold and non-threshold models, are simulated on a computer and compared to the results obtained by Geiselman, Landee & Christen (1982) in a visual search task. A threshold search model in which the time to reject distractors over the similarity threshold is a function of the increment above the threshold (where similarity is defined as proposed in Workman & Fisher, 1987), is shown to provide the best fit to the data. Implications for the selection of symbols for graphic displays are briefly discussed.


Author(s):  
Michael F. Gorman ◽  
Donald L. Fisher

The fact that response times increase as one ages has long been established. Previous research has indicated that a process-specific model does a better job than the model of general slowing in explaining the differences between older and younger adults. This experiment tested a process-specific model of slowing using older and younger adults in a visual search task. The task manipulated the presence of the target, the number of search items, the structure of the display of the search items, the perceptual quality of the search items and the complexity of the response. It was found that encoding, motor, and decision processes were about equally delayed whereas the comparison process was delayed little if any.


Vision ◽  
2021 ◽  
Vol 5 (3) ◽  
pp. 42
Author(s):  
Benjamin A. Motz ◽  
Robert L. Goldstone ◽  
Thomas A. Busey ◽  
Richard W. Prather

In visual search tasks, physically large target stimuli are more easily identified among small distractors than are small targets among large distractors. The present study extends this finding by presenting preliminary evidence of a new search asymmetry: stimuli that symbolically represent larger magnitude are identified more easily among featurally equivalent distractors that represent smaller magnitude. Participants performed a visual search task using line-segment digits representing the numbers 2 and 5, and the numbers 6 and 9, as well as comparable non-numeric control stimuli. In three experiments, we found that search times are faster when the target is a digit that represents a larger magnitude than the distractor, although this pattern was not evident in one additional experiment. The results provide suggestive evidence that the magnitude of a number symbol can affect perceptual comparisons between number symbols, and that the semantic meaning of a target stimulus can systematically affect visual search.


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