Visual Target Acquisition in the Presence of Complex Backgrounds

1979 ◽  
Vol 23 (1) ◽  
pp. 394-396
Author(s):  
Jan Berkhout ◽  
Jeffrey Phillips ◽  
Steven Breidenbach
Keyword(s):  
Visual Field ◽  
Relative Motion ◽  
Visual Target ◽  
Target Acquisition ◽  
Vehicle Accident ◽  
Complex Background ◽  
Edge Sharpness ◽  
Field Edge ◽  
Visual Targets

The perception of simple visual targets superimposed on complex background images was studied. Background images interfered with target perception. At the periphery of the visual field, edge sharpness and relative motion within complex backgrounds determined the degree of interference. Increasing age of the subjects was associated with an increase in such interference. A correlation between target perception and self-reported vehicle accident history was observed.

Neonatal Localisation of a Sound in Visual Space

Perception ◽  
1981 ◽  
Vol 10 (3) ◽  
pp. 331-338 ◽  
Author(s):  
Marcela Castillo ◽  
George Butterworth
Keyword(s):  
Visual Field ◽  
Visual Target ◽  
Visual Space ◽  
Spatial Coordination ◽  
Visual Targets ◽  
Auditory Localisation

A tone was played to neonates in one of four conditions: in an unstructured visual field; spatially concordant with a single visual target; spatially discordant with a single visual target; or spatially concordant with one of two identical visual targets at different locations. Auditory–oculomotor spatial coordination, contingent on sound, was enhanced by the presence of a target in the visual field. Audition and vision are mutually supportive in auditory localisation from birth.

“Motor Oblique Effect”: Perceptual Direction Discrimination and Pointing to Memorized Visual Targets Share the Same Preference for Cardinal Orientations

2007 ◽  
Vol 97 (2) ◽  
pp. 1068-1077 ◽  
Author(s):  
Nikolaos Smyrnis ◽  
Asimakis Mantas ◽  
Ioannis Evdokimidis
Keyword(s):  
Visual Target ◽  
Motor Task ◽  
Oblique Effect ◽  
Quadratic Function ◽  
Initial Direction ◽  
Direction Discrimination ◽  
Pointing Movements ◽  
Equivalent Measure ◽  
Visual Targets ◽  
Target Locations

In previous studies we observed a pattern of systematic directional errors when humans pointed to memorized visual target locations in two-dimensional (2-D) space. This directional error was also observed in the initial direction of slow movements toward visual targets or movements to kinesthetically defined targets in 2-D space. In this study we used a perceptual experiment where subjects decide whether an arrow points in the direction of a visual target in 2-D space and observed a systematic distortion in direction discrimination known as the “oblique effect.” More specifically, direction discrimination was better for cardinal directions than for oblique. We then used an equivalent measure of direction discrimination in a task where subjects pointed to memorized visual target locations and showed the presence of a motor oblique effect. We finally modeled the oblique effect in the perceptual and motor task using a quadratic function. The model successfully predicted the observed direction discrimination differences in both tasks and, furthermore, the parameter of the model that was related to the shape of the function was not different between the motor and the perceptual tasks. We conclude that a similarly distorted representation of target direction is present for memorized pointing movements and perceptual direction discrimination.

scholarly journals A bimodal extension of the Eriksen flanker task

2020 ◽  
Author(s):  
Rolf Ulrich ◽  
Laura Prislan ◽  
Jeff Miller
Keyword(s):  
Visual Target ◽  
Target Item ◽  
Flanker Task ◽  
Response Competition ◽  
Relevant Information ◽  
Irrelevant Information ◽  
Flanker Effect ◽  
Starting Point ◽  
Visual Targets ◽  
Task Irrelevant

Abstract The Eriksen flanker task is a traditional conflict paradigm for studying the influence of task-irrelevant information on the processing of task-relevant information. In this task, participants are asked to respond to a visual target item (e.g., a letter) that is flanked by task-irrelevant items (e.g., also letters). Responses are typically faster and more accurate when the task-irrelevant information is response-congruent with the visual target than when it is incongruent. Several researchers have attributed the starting point of this flanker effect to poor selective filtering at a perceptual level (e.g., spotlight models), which subsequently produces response competition at post-perceptual stages. The present study examined whether a flanker-like effect could also be established within a bimodal analog of the flanker task with auditory irrelevant letters and visual target letters, which must be processed along different processing routes. The results of two experiments revealed that a flanker-like effect is also present with bimodal stimuli. In contrast to the unimodal flanker task, however, the effect only emerged when flankers and targets shared the same letter name, but not when they were different letters mapped onto the same response. We conclude that the auditory flankers can influence the time needed to recognize visual targets but do not directly activate their associated responses.

Dependence of Saccade-Related Activity in the Primate Superior Colliculus on Visual Target Presence

2001 ◽  
Vol 86 (2) ◽  
pp. 676-691 ◽  
Author(s):  
Jay A. Edelman ◽  
Michael E. Goldberg
Keyword(s):  
Superior Colliculus ◽  
Visual Target ◽  
Visual Response ◽  
Target Presence ◽  
Related Activity ◽  
Intermediate Layers ◽  
Saccade Velocity ◽  
Trial Basis ◽  
Visual Targets ◽  
Extracellular Activity

Neurons in the intermediate layers of the superior colliculus respond to visual targets and/or discharge immediately before and during saccades. These visual and motor responses have generally been considered independent, with the visual response dependent on the nature of the stimulus, and the saccade-related activity related to the attributes of the saccade, but not to how the saccade was elicited. In these experiments we asked whether saccade-related discharge in the superior colliculus depended on whether the saccade was directed to a visual target. We recorded extracellular activity of neurons in the intermediate layers of the superior colliculus of three rhesus monkeys during saccades in tasks in which we varied the presence or absence of a visual target and the temporal delays between the appearance and disappearance of a target and saccade initiation. Across our sample of neurons ( n = 64), discharge was highest when a saccade was made to a still-present visual target, regardless of whether the target had recently appeared or had been present for several hundred milliseconds. Discharge was intermediate when the target had recently disappeared and lowest when the target had never appeared during that trial. These results are consistent with the hypothesis that saccade-related discharge decreases as the time between the target disappearance and saccade initiation increases. Saccade velocity was also higher for saccades to visual targets, and correlated on a trial-by-trial basis with perisaccadic discharge for many neurons. However, discharge of many neurons was dependent on task but independent of saccade velocity, and across our sample of neurons, saccade velocity was higher for saccades made immediately after target appearance than would be predicted by discharge level. A tighter relationship was found between saccade precision and perisaccadic discharge. These findings suggest that just as the purpose of the saccadic system in primates is to drive the fovea to a visual target, presaccadic motor activity in the superior colliculus is most intense when such a target is actually present. This enhanced activity may, itself, contribute to the enhanced performance of the saccade system when the saccade is made to a real visual target.

Spatial Multisensory Cueing to Support Visual Target-Acquisition Performance

2012 ◽  
Vol 56 (1) ◽  
pp. 1312-1316 ◽  
Author(s):  
Julio C. Mateo ◽  
Brian D. Simpson ◽  
Robert H. Gilkey ◽  
Nandini Iyer ◽  
Douglas S. Brungart
Keyword(s):  
Visual Target ◽  
Target Acquisition ◽  
Acquisition Performance

Visual Target Acquisition: Bridging the Gap from Vision Research to Applied Models

1992 ◽  
Vol 36 (18) ◽  
pp. 1418-1419
Author(s):  
Theodore J. Doll
Keyword(s):  
Vision Research ◽  
Visual Target ◽  
Lessons Learned ◽  
The Other ◽  
Bad News ◽  
Good News ◽  
Target Acquisition ◽  
Ground Vehicles ◽  
Desert Storm ◽  
Highly Effective

One of the lessons learned in Desert Storm is that visual and electro-optical (VISEO) systems are highly effective. Most of us recall seeing CNN footage of EO sensors acquiring targets and guiding weapons to destroy the target. The effectiveness of VISEO systems is the good news. The bad news is that the other side is likely to be equipped with similar VISEO systems in the next war. Our personnel and materiel are therefore likely to be highly vulnerable to such systems in future conflicts. There is an urgent need to make our weapons systems, especially ground vehicles, less conspicuous on the battlefield, i.e., to develop more effective camouflage and signature suppression techniques.

Controlling Contrast in Target Acquisition Simulations Involving Complex Backgrounds

1992 ◽  
Vol 36 (18) ◽  
pp. 1435-1439
Author(s):  
William Kosnik
Keyword(s):  
Simple Technique ◽  
Visual Target ◽  
Systematic Effect ◽  
Target Acquisition ◽  
Low Contrast ◽  
Performance Factors ◽  
Background Structure ◽  
Inherent Feature ◽  
Uniform Background ◽  
Natural Terrain

Visual target acquisition (TA) often involves detecting targets against natural backgrounds that have complex luminance distributions. The purpose of this study was to evaluate a simple technique that controls target contrast in the presence of varying backgrounds. Target contrast was measured by the root mean square (rms) method and was controlled by adjusting only the target luminance, leaving the background unchanged. The technique was tested in a TA paradigm in which observers searched for an aircraft that was embedded in 1) a uniform background, 2) a natural terrain background, or 3) a moving natural terrain background. Four target contrast levels were tested. The results showed that TA time varied with background and target contrast. Significant differences in TA time were observed among the different backgrounds for targets of the same physical contrast, especially at low contrast levels. Although contrast had a systematic effect on TA performance, factors other than contrast influenced TA performance. It was concluded that background structure increased TA time by camouflaging targets and by introducing distractors to the task. Such an approach could be used to model TA performance under conditions where target and background complexity are an inherent feature of the TA task.

Visual Search and Detection in Background Clutter

1992 ◽  
Vol 36 (18) ◽  
pp. 1420-1424
Author(s):  
Theodore J. Doll ◽  
Shane W. McWhorter ◽  
David E. Schmieder
Keyword(s):  
Real World ◽  
Vision Research ◽  
Visual Target ◽  
Basic Research ◽  
Pattern Perception ◽  
Target Acquisition ◽  
Engineering Models ◽  
Background Clutter ◽  
Improved Model ◽  
Transfer Of Information

Two traditions of vision modeling have coexisted for many years with little or no transfer of information between them. Those interested in models of visual target acquisition for real-world scenarios have developed engineering models, which are essentially empirical summaries of visual performance data. On the other hand, basic researchers in visual psychophysics and neurophysiology have developed quantitative models of pattern perception. The basic research models have increased in generality and scope to the point that they are potentially powerful tools for addressing certain real-world needs that have recently come to the fore. The needs include quantitative, theory-based methods for evaluating target signatures, effects of background clutter, and observer false alarm rates. This paper reviews the shortcomings of existing target acquisition models, and reports work in progress to develop an improved model of target acquisition that incorporates a model of pattern perception from basic vision research.

Combined 3-D auditory-visual cueing for a visual target acquisition task

2007 ◽  
Author(s):  
Rachael L. Westergren ◽  
Paul R. Havig ◽  
Eric L. Heft
Keyword(s):  
Visual Target ◽  
Target Acquisition ◽  
Visual Cueing ◽  
Acquisition Task
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