OVERT AND COVERT VISUAL SEARCH IN PRIMATES: REACTION TIMES AND GAZE SHIFT STRATEGIES

2009 ◽  
Vol 08 (02) ◽  
pp. 137-174 ◽  
Author(s):  
HANS-CHRISTOPH NOTHDURFT ◽  
IVAN N. PIGAREV ◽  
SABINE KASTNER
Keyword(s):  
Visual Search ◽  
Reaction Times ◽  
Gaze Shift

scholarly journals Age-related changes in visual search: manipulation of colour cues based on cone contrast and opponent modulation space

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shuto Tamura ◽  
Keiko Sato
Keyword(s):  
Visual Search ◽  
Visual Attention ◽  
Reaction Times ◽  
Visual Space ◽  
Preliminary Evidence ◽  
Human Lens ◽  
Search Performance ◽  
Older Individuals ◽  
Colour Perception ◽  
Age Related

AbstractReduced retinal illuminance affects colour perception in older adults, and studies show that they exhibit deficiencies in yellow-blue (YB) discrimination. However, the influence of colour cues on the visual attention in older individuals remains unclarified. Visual attention refers to the cognitive model by which we prioritise regions within the visual space and selectively process information. The present study aimed to explore the effect of colour on visual search performance in older observers. In our experiment, younger observers wearing glasses with a filter that simulated the spectral transmittance of the aging human lens and older observers performed two types of search tasks, feature search (FS) and conjunction search (CS), under three colour conditions: red-green, YB, and luminance. Targets and distractors were designed on the basis of the Derrington–Krauskopf–Lennie colour representation. In FS tasks, reaction times changed according to colour in all groups, especially under the YB condition, regardless of the presence or absence of distractors. In CS tasks with distractors, older participants and younger participants wearing glasses showed slower responses under chromatic conditions than under the achromatic condition. These results provide preliminary evidence that, for older observers, visual search performance may be affected by impairments in chromatic colour discrimination.

Serial and Parallel Search in Pattern Vision?

Perception ◽  
1987 ◽  
Vol 16 (3) ◽  
pp. 389-398 ◽  
Author(s):  
Scott B Steinman
Keyword(s):  
Visual Search ◽  
Visual Field ◽  
Reaction Times ◽  
Positional Information ◽  
Human Vision ◽  
The Other ◽  
Parallel Search ◽  
Lateral Separation ◽  
Serial Search ◽  
Initial Results

The nature of the processing of combinations of stimulus dimensions in human vision has recently been investigated. A study is reported in which visual search for suprathreshold positional information—vernier offsets, stereoscopic disparity, lateral separation, and orientation—was examined. The initial results showed that reaction times for visual search for conjunctions of stereoscopic disparity and either vernier offsets or orientation were independent of the number of distracting stimuli displayed, suggesting that disparity was searched in parallel with vernier offsets or orientation. Conversely, reaction times for detection of conjunctions of vernier offsets and orientation, or lateral separation and each of the other positional judgements, were related linearly to the number of distractors, suggesting serial search. However, practice has a significant effect upon the results, indicative of a shift in the mode of search from serial to parallel for all conjunctions tested as well as for single features. This suggests a reinter-pretation of these and perhaps other studies that use the Treisman visual search paradigm, in terms of perceptual segregation of the visual field by disparity, motion, color, and pattern features such as colinearity, orientation, lateral separation, or size.

scholarly journals Effects of visual blur on microsaccades during visual exploration

2019 ◽  
Vol 12 (6) ◽  
Author(s):  
Sherry Tang ◽  
Peggy Skelly ◽  
Jorge Otero-Millan ◽  
Jonathan Jacobs ◽  
Jordan Murray ◽  
...  
Keyword(s):  
Visual Search ◽  
Refractive Error ◽  
Reaction Times ◽  
Sampling Strategy ◽  
Visual Exploration ◽  
Optimal Sampling ◽  
Scene Viewing ◽  
Gaze Holding ◽  
The Difference ◽  
Uncorrected Refractive Error

Microsaccades shift the image on the fovea and counteract visual fading. They also serve as an optimal sampling strategy while viewing complex visual scenes. Microsaccade production relies on the amount of retinal error or acuity demand of a visual task. The goal of this study was to assess the effects of blur induced by uncorrected refractive error on visual search. Eye movements were recorded in fourteen healthy subjects with uncorrected and corrected refractive error while they performed a) visual fixation b) blank-scene viewing c) visual search (spot the difference) tasks. Microsaccades, saccades, correctly identified differences and reaction times were analyzed. The frequency of microsaccades and correctly identified differences were lower in the uncorrected refractive error during visual search. No similar change in microsaccades was seen during blank-scene viewing and gaze holding tasks. These findings suggest that visual blur, hence the precision of an image on the fovea, has an important role in calibrating the amplitude of microsaccades during visual scanning.

scholarly journals Color’s Indispensable Role in the Rapid Detection of Food

2021 ◽  
Vol 12 ◽  
Author(s):  
Wataru Sato
Keyword(s):  
Visual Search ◽  
Food Processing ◽  
Fast Food ◽  
Rapid Detection ◽  
Reaction Times ◽  
Color Images ◽  
Psychological Experiment ◽  
Psychological Studies

The detection of food is crucial for our survival and health. Earlier experimental psychological studies have demonstrated that participants detect food more rapidly than non-food stimuli. However, it remains unknown whether color, which was shown to have various influences on food processing, can modulate the detection of food. To address this issue, a psychological experiment was conducted using a visual search paradigm in which photographs of food (fast food and Japanese food) and kitchen utensils were presented alongside images of non-food distractors (cars), with both color and gray images used. Participants used a key to indicate whether one item was different from the rest, and their reaction times (RTs) were measured. RTs for the detection of both food types were shorter than for the kitchen utensils when color images were used, but not when gray images were used; moreover, the RTs were slower for gray images than for color images for both food types but not for kitchen utensils. These results indicate that color facilitates rapid detection of food in the environment.

scholarly journals Reliance on central vs. peripheral vision for visual search in younger and older adults

2020 ◽  
Author(s):  
Anne-Sophie Laurin ◽  
Julie Ouerfelli-Éthier ◽  
Laure Pisella ◽  
Aarlenne Zein Khan
Keyword(s):  
Older Adults ◽  
Visual Search ◽  
Peripheral Vision ◽  
Reaction Times ◽  
Central Vision ◽  
Younger Adults ◽  
Serial Search ◽  
Attentional Resources ◽  
Search Tasks ◽  
Fixation Durations

Older adults show declines performing visual search, but their nature is unclear. We propose that it is related to greater attentional reliance on central vision. To investigate this, we tested how occluding central vision would affect younger and older adults in visual search. Participants (14 younger, M = 21.6 years; 16 older, M = 69.6 years) performed pop-out and serial search tasks in full view and with different sized gaze-contingent artificial central scotomas (no scotoma, 3°, 5° or 7° diameter).In pop-out search, older adults showed longer search times for peripheral targets during full viewing. Their reaction times, saccades and fixation durations also increased as a function of scotoma size, contrary to younger adults. These declines may reflect a relative impairment in peripheral visual attention for global processing in aging.In serial search, despite older adults being generally slower, we found no difference between groups in reaction time increases for eccentric targets and for bigger scotomas. These results may come from the difficulty of serial search, in which both groups used centrally limited attentional windows.We conclude that older adults allocate more attentional resources towards central vision compared to younger adults, impairing their peripheral processing primarily in pop-out visual search.

Temporal Processing of Saccade Targets in Parietal Cortex Area LIP During Visual Search

2007 ◽  
Vol 97 (1) ◽  
pp. 942-947 ◽  
Author(s):  
Neil W. D. Thomas ◽  
Martin Paré
Keyword(s):  
Visual Search ◽  
Parietal Cortex ◽  
Activity Patterns ◽  
Reaction Times ◽  
Stimulus Presentation ◽  
Ideal Observer ◽  
Cortex Area ◽  
The Individual ◽  
Visual Cortical ◽  
Selection Of

We studied whether the lateral intraparietal (LIP) area—a subdivision of parietal cortex anatomically interposed between visual cortical areas and saccade executive centers—contains neurons with activity patterns sufficient to contribute to the active process of selecting saccade targets in visual search. Visually responsive neurons were recorded while monkeys searched for a color-different target presented concurrently with seven distractors evenly distributed in a circular search array. We found that LIP neurons initially responded indiscriminately to the presentation of a visual stimulus in their response fields, regardless of its feature and identity. Their activation nevertheless evolved to signal the search target before saccade initiation: an ideal observer could reliably discriminate the target from the individual activation of 60% of neurons, on average, 138 ms after stimulus presentation and 26 ms before saccade initiation. Importantly, the timing of LIP neuronal discrimination varied proportionally with reaction times. These findings suggest that LIP activity reflects the selection of both the search target and the targeting saccade during active visual search.

Association Between Action Video Game Playing Experience and Visual Search in Real-life Multisensory scenes

2021 ◽  
Author(s):  
Mohammad Hamzeloo ◽  
Daria Kvasova ◽  
Salvador Soto-Faraco
Keyword(s):  
Visual Search ◽  
Video Games ◽  
Video Game ◽  
Attentional Control ◽  
Search Task ◽  
Visual Search Task ◽  
Real Life ◽  
Reaction Times ◽  
Action Video Game ◽  
Action Video Games

Prior studies investigating the effects of playing action video games on attentional control have demonstrated improvements on a variety of basic psychophysical tasks. However, as of yet, there is little evidence indicating that the cognitive benefits of playing action video games generalize to naturalistic multisensory scenes - a fundamental characteristic of our natural, everyday life environments. The present study addressed the generalization of attentional control enhancement due to AVGP experience to real-life like scenarios by comparing the performance of action video-game players (AVGPs) with non-players (NVGPs) on a visual search task using naturalistic, dynamic audio-visual scenes. To this end, a questionnaire collecting data on gaming habits and sociodemographic data as well as a visual search task was administered online to a gender-balanced sample of 60 participants of age 18 to 30 years. According to the standard hypothesis, AVGPs outperformed NVGPs in the search task overall, showing faster reaction times without sacrificing accuracy. In addition, in replication of previous findings, semantically congruent cross-modal cues benefited performance overall. However, according to our results, despite the overall advantage in search, and the multisensory congruence benefit, AVGPs did not exploit multisensory cues more efficiently than NVGPs. Exploratory analyses with gender as a variable indicated that the advantage of AVG experience to both genders should be done with caution.

scholarly journals Effect of Reversible Inactivation of Superior Colliculus on Head Movements

2008 ◽  
Vol 99 (5) ◽  
pp. 2479-2495 ◽  
Author(s):  
Mark M. G. Walton ◽  
Bernard Bechara ◽  
Neeraj J. Gandhi
Keyword(s):  
Superior Colliculus ◽  
Reaction Times ◽  
Movement Control ◽  
Head Movements ◽  
Gaze Shifts ◽  
Gaze Shift ◽  
Reversible Inactivation ◽  
The Gaze ◽  
Made In

Because of limitations in the oculomotor range, many gaze shifts must be accomplished using coordinated movements of the eyes and head. Stimulation and recording data have implicated the primate superior colliculus (SC) in the control of these gaze shifts. The precise role of this structure in head movement control, however, is not known. The present study uses reversible inactivation to gain insight into the role of this structure in the control of head movements, including those that accompany gaze shifts and those that occur in the absence of a change in gaze. Forty-five lidocaine injections were made in two monkeys that had been trained on a series of behavioral tasks that dissociate movements of the eyes and head. Reversible inactivation resulted in clear impairments in the animals’ ability to perform gaze shifts, manifested by increased reaction times, lower peak velocities, and increased durations. In contrast, comparable effects were not found for head movements (with or without gaze shifts) with the exception of a very small increase in reaction times of head movements associated with gaze shifts. Eye-head coordination was clearly affected by the injections with gaze onset occurring relatively later with respect to head onset. Following the injections, the head contributed slightly more to the gaze shift. These results suggest that head movements (with and without gaze shifts) can be controlled by pathways that do not involve SC.

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