The Speed of Visual Search in the Absence of Sensory Effects

Perception ◽  
1997 ◽  
Vol 26 (1) ◽  
pp. 85-91 ◽  
Author(s):  
Jukka Saarinen
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Search Time ◽  
Search Display ◽  
Serial Search ◽  
Set Size ◽  
Sensory Effects ◽  
Stimulus Block ◽  
Target Experiment ◽  
Target Locations

The purpose of this study was to investigate the efficiency or speed of the frequently used L versus T visual search when sensory effects were controlled, ie ‘set size’ was not defined as the number of distractor patterns, but the number of distractors in the display was kept constant and the number of possible target positions varied. A search display consisted of an L-target among T-distractors, and the observer's task was to report the presence or absence of the target (experiment 1) or to identify it (whether the L-target was left-facing or right-facing; experiment 2). The observer was instructed prior to each stimulus block, about the display locations in which the target could appear. In both experiments, search time increased significantly with an increasing number of possible target locations, thus indicating that L versus T search is not ‘serial’ owing to sensory effects. Because, in the first two experiments, a search display was visible until the observer gave a response, ‘serial’ search might have resulted just from eye movements. Therefore, a control experiment was run in which display duration was limited to 150 ms. The results of this experiment showed that, even when eye movements were prevented, the search still occurred ‘serially’, ie response time increased as a function of the number of possible target positions.

Gaze Linking in Visual Search: A Help or a Hindrance?

2017 ◽  
Vol 61 (1) ◽  
pp. 1376-1379 ◽  
Author(s):  
Nathan Messmer ◽  
Nathan Leggett ◽  
Melissa Prince ◽  
Jason S. McCarley
Keyword(s):  
Visual Search ◽  
Eye Movements ◽  
Search Task ◽  
Response Times ◽  
Visual Task ◽  
Serial Search ◽  
Team Members ◽  
Search Tasks ◽  
Computer Monitors

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.

Set size slope still does not distinguish parallel from serial search

2017 ◽  
Vol 40 ◽  
Author(s):  
Daniel R. Little ◽  
Ami Eidels ◽  
Joseph W. Houpt ◽  
Cheng-Ta Yang
Keyword(s):  
Visual Search ◽  
Serial Search ◽  
Set Size ◽  
Model Mimicry

AbstractMuch of the evidence for theories in visual search (including Hulleman & Olivers' [H&O's]) comes from inferences made using changes in mean RT as a function of the number of items in a display. We have known for more than 40 years that these inferences are based on flawed reasoning and obscured by model mimicry. Here we describe a method that avoids these problems.

Distractor Heterogeneity versus Linear Separability in Colour Visual Search

Perception ◽  
1996 ◽  
Vol 25 (11) ◽  
pp. 1281-1293 ◽  
Author(s):  
Ben Bauer ◽  
Pierre Jolicoeur ◽  
William B Cowan
Keyword(s):  
Visual Search ◽  
Search Display ◽  
Search Performance ◽  
Set Size ◽  
Linear Separability

D'Zmura, and Bauer, Jolicoeur, and Cowan demonstrated that a target whose chromaticity was linearly separable from distractor chromaticities was relatively easy to detect in a search display, whereas a target that was not linearly separable from the distractor chromaticities resulted in steep search slopes. This linear separability effect suggests that efficient colour visual search is mediated by a chromatically linear mechanism. Failure of this mechanism leads to search performance strongly influenced by number of search items (set size). In their studies, linear separability was confounded with distractor heterogeneity and thus the results attributed to linear separability were also consistent with the model of visual search proposed by Duncan and Humphreys in which search performance is determined in part by distractor heterogeneity. We contrasted the predictions based on linear separability and on the Duncan and Humphreys model by varying the ratios of the quantities of the two distractors and demonstrated the potent effects of linear separability in a design that deconfounded linear separability and distractor heterogeneity.

scholarly journals The Speed of Serial Attention Shifts in Visual Search: Evidence from the N2pc Component

2016 ◽  
Vol 28 (2) ◽  
pp. 319-332 ◽  
Author(s):  
Anna Grubert ◽  
Martin Eimer
Keyword(s):  
Visual Search ◽  
Visual Field ◽  
Search Task ◽  
Serial Order ◽  
Search Display ◽  
Color Target ◽  
Selection Models ◽  
Sequential Movements ◽  
Target Locations ◽  
Attention Shifts

Finding target objects among distractors in visual search display is often assumed to be based on sequential movements of attention between different objects. However, the speed of such serial attention shifts is still under dispute. We employed a search task that encouraged the successive allocation of attention to two target objects in the same search display and measured N2pc components to determine how fast attention moved between these objects. Each display contained one digit in a known color (fixed-color target) and another digit whose color changed unpredictably across trials (variable-color target) together with two gray distractor digits. Participants' task was to find the fixed-color digit and compare its numerical value with that of the variable-color digit. N2pc components to fixed-color targets preceded N2pc components to variable-color digits, demonstrating that these two targets were indeed selected in a fixed serial order. The N2pc to variable-color digits emerged approximately 60 msec after the N2pc to fixed-color digits, which shows that attention can be reallocated very rapidly between different target objects in the visual field. When search display durations were increased, thereby relaxing the temporal demands on serial selection, the two N2pc components to fixed-color and variable-color targets were elicited within 90 msec of each other. Results demonstrate that sequential shifts of attention between different target locations can operate very rapidly at speeds that are in line with the assumptions of serial selection models of visual search.

scholarly journals Individual differences in visual search performance extend from artificial arrays to naturalistic environments.

2021 ◽  
Author(s):  
Thomas L. Botch ◽  
Brenda D. Garcia ◽  
Yeo Bi Choi ◽  
Caroline E. Robertson
Keyword(s):  
Individual Differences ◽  
Visual Search ◽  
Eye Movements ◽  
Real World ◽  
Search Task ◽  
Visual Search Task ◽  
Search Behavior ◽  
Search Performance ◽  
Set Size ◽  
Visual Clutter

Visual search is a universal human activity in naturalistic environments. Traditionally, visual search is investigated under tightly controlled conditions, where head-restricted participants locate a minimalistic target in a cluttered array presented on a computer screen. Do classic findings of visual search extend to naturalistic settings, where participants actively explore complex, real-world scenes? Here, we leverage advances in virtual reality (VR) technology to relate individual differences in classic visual search paradigms to naturalistic search behavior. In a naturalistic visual search task, participants looked for an object within their environment via a combination of head-turns and eye-movements using a head-mounted display. Then, in a classic visual search task, participants searched for a target within a simple array of colored letters using only eye-movements. We tested how set size, a property known to limit visual search within computer displays, predicts the efficiency of search behavior inside immersive, real-world scenes that vary in levels of visual clutter. We found that participants' search performance was impacted by the level of visual clutter within real-world scenes. Critically, we also observed that individual differences in visual search efficiency in classic search predicted efficiency in real-world search, but only when the comparison was limited to the forward-facing field of view for real-world search. These results demonstrate that set size is a reliable predictor of individual performance across computer-based and active, real-world visual search behavior.

scholarly journals There is more to contextual cuing than meets the eye: Improving visual search without attentional guidance towards predictable target locations

2020 ◽  
Author(s):  
Miguel A. Vadillo ◽  
Tamara Giménez-Fernández ◽  
Tom Beesley ◽  
David Shanks ◽  
David Luque
Keyword(s):  
Visual Search ◽  
Essential Role ◽  
Search Display ◽  
Repeated Exposure ◽  
Visual Scene ◽  
Contextual Cuing ◽  
Attentional Guidance ◽  
Research Participants ◽  
Usual Location ◽  
Target Locations

It is usually easier to find objects in a visual scene as we gain familiarity with it. Two decades of research on contextual cuing of visual search show that repeated exposure to a search display can facilitate the detection of targets that appear at predictable locations in that display. Typical accounts for this effect attribute an essential role to learned associations between the target and other stimuli in the search display. These associations improve visual search either by driving attention towards the usual location of the target or by facilitating its recognition. Contrary to this view, we show that a robust contextual cuing effect can also be observed when repeated search displays do not allow the location of the target to be predicted. These results suggest that, in addition to the mechanisms already explored by previous research, participants learn to ignore the locations usually occupied by distractors, which in turn facilitates the detection of targets even when they appear in unpredictable locations.

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.

Effects of Symbol Structure on Visual Information Processing

1983 ◽  
Vol 27 (5) ◽  
pp. 354-354
Author(s):  
Bruce W. Hamill ◽  
Robert A. Virzi
Keyword(s):  
Information Processing ◽  
Visual Processing ◽  
Visual Information ◽  
Context Effects ◽  
Response Times ◽  
Search Time ◽  
Visual Information Processing ◽  
Array Size ◽  
Serial Search ◽  
Feature Structure

This investigation addresses the problem of attention in the processing of symbolic information from visual displays. Its scope includes the nature of attentive processes, the structural properties of stimuli that influence visual information processing mechanisms, and the manner in which these factors interact in perception. Our purpose is to determine the effects of configural feature structure on visual information processing. It is known that for stimuli comprising separable features, one can distinguish between conditions in which only one relevant feature differs among stimuli in the array being searched and conditions in which conjunctions of two (or more) features differ: Since the visual process of conjoining separable features is additive, this fact is reflected in search time as a function of array size, with feature conditions yielding flat curves associated with parallel search (no increase in search time across array sizes) and conjunction conditions yielding linearly increasing curves associated with serial search. We studied configural-feature stimuli within this framework to determine the nature of visual processing for such stimuli as a function of their feature structure. Response times of subjects searching for particular targets among structured arrays of distractors were measured in a speeded visual search task. Two different sets of stimulus materials were studied in array sizes of up to 32 stimuli, using both tachistoscope and microcomputer-based CRT presentation for each. Our results with configural stimuli indicate serial search in all of the conditions, with the slope of the response-time-by-array-size function being steeper for conjunction conditions than for feature conditions. However, for each of the two sets of stimuli we studied, there was one configuration that stood apart from the others in its set in that it yielded significantly faster response times, and in that conjunction conditions involving these particular stimuli tended to cluster with the feature conditions rather than with the other conjunction conditions. In addition to these major effects of particular targets, context effects also appeared in our results as effects of the various distractor sets used; certain of these context effects appear to be reversible. The effects of distractor sets on target search were studied in considerable detail. We have found interesting differences in visual processing between stimuli comprising separable features and those comprising configural features. We have also been able to characterize the effects we have found with configural-feature stimuli as being related to the specific feature structure of the target stimulus in the context of the specific feature structure of distractor stimuli. These findings have strong implications for the design of symbology that can enhance visual performance in the use of automated displays.

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