Scan path during change-detection visual search

2021 ◽  
Vol 131 ◽  
pp. 104233
Author(s):  
Srikrishnaraja Mahadas ◽  
Courtney Semkewyc ◽  
Shradha Suresh ◽  
George K. Hung
Keyword(s):  
Visual Search ◽  
Change Detection ◽  
Scan Path

scholarly journals An Eye Tracking Analysis on Diagnostic Performance of Digital Fundus Photography Images between Ophthalmologists and Optometrists

2019 ◽  
Vol 17 (1) ◽  
pp. 30
Author(s):  
Mizhanim Mohamad Shahimin ◽  
Azalia Razali
Keyword(s):  
Visual Search ◽  
Eye Movement ◽  
Correct Diagnosis ◽  
Fundus Photography ◽  
Eye Tracker ◽  
Total Fixation ◽  
Search Patterns ◽  
Scan Path ◽  
Scan Paths ◽  
Fundus Photographs

To investigate the parameters of eye movement between ophthalmologists and optometrists while diagnosing digital fundus photographs, sixteen participants (eight ophthalmologists and eight optometrists) were recruited in this study. Every participant’s eye movement during diagnosis of a randomized set of fundus photographs displayed on an eye tracker were recorded. Fixation metrics (duration, count and rate) and scan path patterns were extracted from the eye tracker. These parameters of eye movement and correct diagnosis score were compared between both groups. Correlation analyses between fixation metrics and correct diagnosis score were also performed. Although fixation metrics between ophthalmologists and optometrists were not statistically different (p > 0.05), these parameters were statistically different when compared between different area of interests. Both participant groups had a similar correct diagnosis score. No correlation was found between fixation metrics and correct diagnosis score between both groups, except for total fixation duration and ophthalmologists’ diagnosis score of diabetic retinopathy photographs. The ophthalmologists’ scan paths were simpler, with larger saccades, and were distributed at the middle region of the photographs. Conversely, optometrists’ scan paths were extensive, with shorter saccades covering wider fundus areas, and were accumulated in some unrelated fundus areas. These findings indicated comparable efficiency and systematic visual search patterns between both the groups. Understanding visual search strategy could expedite the creation of a novel training routine for interpretation of ophthalmic diagnostic imaging.

scholarly journals Spatial context learning in visual search and change detection

2005 ◽  
Vol 67 (7) ◽  
pp. 1128-1139 ◽  
Author(s):  
Yuhong Jiang ◽  
Joo-Hyun Song
Keyword(s):  
Visual Search ◽  
Change Detection ◽  
Spatial Context ◽  
Context Learning

scholarly journals Visual search without central vision – no single pseudofovea location is best

2014 ◽  
Vol 7 (2) ◽  
Author(s):  
Angelika Lingnau ◽  
Thorsten Albrecht ◽  
Jens Schwarzbach ◽  
Dirk Vorberg
Keyword(s):  
Visual Search ◽  
Macular Degeneration ◽  
Spatial Resolution ◽  
Central Vision ◽  
Foveal Vision ◽  
Scan Path ◽  
Path Direction ◽  
Retinal Region ◽  
Field Location

We typically fixate targets such that they are projected onto the fovea for best spatial resolution. Macular degeneration patients often develop fixation strategies such that targets are projected to an intact eccentric part of the retina, called pseudofovea. A longstanding debate concerns which pseudofovea-location is optimal for non-foveal vision. We examined how pseudofovea position and eccentricity affect performance in visual search, when vision is restricted to an off-foveal retinal region by a gaze-contingent display that dynamically blurs the stimulus except within a small viewing window (forced field location). Trained normally sighted participants were more accurate when forced field location was congruent with the required scan path direction; this contradicts the view that a single pseudofovea location is generally best. Rather, performance depends on the congruence between pseudofovea location and scan path direction.

scholarly journals The effects of learning on visual search and change detection

2010 ◽  
Vol 9 (8) ◽  
pp. 182-182
Author(s):  
C. Mullin ◽  
E. Richards
Keyword(s):  
Visual Search ◽  
Change Detection

The Prioritization of Feature Singletons in the Change Detection Paradigm

2009 ◽  
Vol 56 (2) ◽  
pp. 134-146 ◽  
Author(s):  
Geoff G. Cole ◽  
Gustav Kuhn ◽  
Charles A. Heywood ◽  
Robert W. Kentridge
Keyword(s):  
Visual Search ◽  
Change Detection ◽  
Change Blindness ◽  
Bottom Up ◽  
Attentional Set ◽  
Stringent Test

Six experiments are reported investigating whether a discontinuity in colour can accrue attentional priority. In addition to a standard visual search paradigm, we examined the degree to which colour singletons and nonsingletons are susceptible to change blindness. Results showed that changes occurring at colour singletons were relatively more resistant to change blindness. Although suggestive of bottom-up marshalling of attention, no prioritization of the singleton occurred when the most stringent test of stimulus-driven attentional attraction was employed, that is, when attending to the singleton was detrimental to the task. We conclude that a discontinuity in colour will attract attention unless an attentional set is contrary to singletons.

Dissociating the Neural Mechanisms of Visual Attention in Change Detection Using Functional MRI

2001 ◽  
Vol 13 (7) ◽  
pp. 1006-1018 ◽  
Author(s):  
Scott A. Huettel ◽  
Güven Güzeldere ◽  
Gregory McCarthy
Keyword(s):  
Visual Search ◽  
Visual Attention ◽  
Change Detection ◽  
Visual Cues ◽  
Semantic Processing ◽  
Change Blindness ◽  
Brain Regions ◽  
Detection Task ◽  
Extrastriate Cortex ◽  
Change Detection Task

We investigated using functional magnetic resonance imaging (fMRI) the neural processes associated with performance of a change-detection task. In this task, two versions of the same picture are presented in alternation, separated by a brief mask interval. Even when the two pictures greatly differ (e.g., as when a building is in different locations), subjects report that identification of the change is difficult and often take 30 or more seconds to identify the change. This phenomenon of “change blindness” provides a powerful and novel paradigm for segregating components of visual attention using fMRI that can otherwise be confounded in short-duration tasks. By using a response-contingent event-related analysis technique, we successfully dissociated brain regions associated with different processing components of a visual change-detection task. Activation in the calcarine cortex was associated with task onset, but did not vary with the duration of visual search. In contrast, the pattern of activation in dorsal and ventral visual areas was temporally associated with the duration of visual search. As such, our results support a distinction between brain regions whose activation is modulated by attentional demands of the visual task (extrastriate cortex) and those that are not affected by it (primary visual cortex). A second network of areas including central sulcus, insular, and inferior frontal cortical areas, along with the thalamus and basal ganglia, showed phasic activation tied to the execution of responses. Finally, parietal and frontal regions showed systematic deactivations during task performance, consistent with previous reports that these regions may be associated with nontask semantic processing. We conclude that detection of change, when transient visual cues are not present, requires activation of extrastriate visual regions and frontal regions responsible for eye movements. These results suggest that studies of change blindness can inform understanding of more general attentional processing.

scholarly journals A Search Advantage for Horizontal Targets in Dynamic Displays

i-Perception ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 204166952110046
Author(s):  
Ian M. Thornton ◽  
Quoc C. Vuong ◽  
Karin S. Pilz
Keyword(s):  
Visual Search ◽  
Change Detection ◽  
Visual Processing ◽  
Display Size ◽  
Top Down ◽  
Future Studies ◽  
Strong Orientation ◽  
Dynamic Target ◽  
Underlying Mechanisms ◽  
Lines Of Evidence

Several lines of evidence point to the existence of a visual processing advantage for horizontal over vertical orientations. We investigated whether such a horizontal advantage exists in the context of top-down visual search. Inspired by change detection studies, we created displays where a dynamic target -- a horizontal or a vertical group of five dots that changed contrast synchronously -- was embedded within a randomly flickering grid of dots. The display size (total dots) varied across trials, and the orientation of the target was constant within interleaved blocks. As expected, search was slow and inefficient. Importantly, participants were almost a second faster finding horizontal compared to vertical targets. They were also more efficient and more accurate during horizontal search. Such findings establish that the attentional templates thought to guide search for known targets can exhibit strong orientation anisotropies. We discuss possible underlying mechanisms and how these might be explored in future studies.

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