Related Experiment Video
Updated: May 8, 2026
13:00
Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments
Published on: January 23, 2017
Attention in natural scenes: contrast affects rapid visual processing and fixations alike.
Bernard Marius 't Hart1, Hannah Claudia Elfriede Fanny Schmidt, Ingo Klein-Harmeyer
1Department of Neurophysics, Philipps-University Marburg, , Marburg, Germany.
Summary
Covert and overt attention, crucial for processing natural scenes, are linked. Target contrast relative to background influences both detection and gaze, with objects prioritized over low-level features.
Area of Science:
- Visual attention research
- Cognitive neuroscience
- Image perception
Background:
- Attention is measured by rapid detection (covert) or prolonged viewing (overt).
- These paradigms operate on different timescales and may involve distinct attentional mechanisms.
- Understanding their relationship in naturalistic settings is crucial.
Purpose of the Study:
- To compare covert and overt attention measures in natural scenes.
- To investigate the role of contrast manipulation in target detection and gaze allocation.
- To determine if object precedence over low-level features influences attention.
Main Methods:
- Participants performed target detection in rapid sequences or freely viewed images with gaze tracking.
- Stimuli featured modified target and background contrast.
- Object-unrelated contrast changes were also presented.
Main Results:
- Increased target contrast improved both detection and fixation.
- Decreased target contrast with increased background contrast had minimal impact.
- Objects attracted more gaze than unrelated contrast changes, showing object precedence.
- Detection and fixation probabilities were correlated across paradigms.
Conclusions:
- The link between overt and covert attention extends to naturalistic scenarios.
- Contrast relative to the background is a key factor in visual attention.
- Attentional processing prioritizes objects over simple visual features.
More Related Videos
Related Concept Videos
01:24Color Vision
Color perception begins in the retina, the light-sensitive layer at the back of the eye. Two main theories explain how colors are seen: the trichromatic theory and the opponent-process theory. The trichromatic theory, proposed by Thomas Young in 1802 and extended by Hermann von Helmholtz in 1852, suggests that color vision is based on three types of cone receptors in the retina. These cones are sensitive to different but overlapping ranges of wavelengths corresponding to red, blue, and green.
01:20Parallel Processing
The brain processes sensory information rapidly due to parallel processing, which involves sending data across multiple neural pathways at the same time. This method allows the brain to manage various sensory qualities, such as shapes, colors, movements, and locations, all concurrently. For instance, when observing a forest landscape, the brain simultaneously processes the movement of leaves, the shapes of trees, the depth between them, and the various shades of green. This enables a quick and...
01:21Gestalt Principles of Perception
Gestalt principles provide a framework for understanding how humans perceive objects as unified wholes within their context. These principles are essential in explaining the cognitive processes that make sense of complex visual stimuli by organizing them into coherent groups. One fundamental principle is proximity, which posits that objects located close to each other are perceived as a collective group. For instance, when dots are positioned near one another, the visual system interprets them...
01:24Vision
Vision is the result of light being detected and transduced into neural signals by the retina of the eye. This information is then further analyzed and interpreted by the brain. First, light enters the front of the eye and is focused by the cornea and lens onto the retina—a thin sheet of neural tissue lining the back of the eye. Because of refraction through the convex lens of the eye, images are projected onto the retina upside-down and reversed.
01:20Anatomy of the Eyeball
The eye is a spherical, hollow structure composed of three tissue layers. The outer layer — the fibrous tunic, comprises the sclera — a white structure — and the cornea, which is transparent. The sclera encompasses some of the ocular surface, most of which is not visible. However, the 'white of the eye' is distinctively visible in humans compared to other species. The cornea, a clear covering at the front of the eye, enables light penetration. The eye's middle layer, the vascular tunic,...
01:15Depth Perception and Spatial Vision
Depth perception is the ability to perceive objects three-dimensionally. It relies on two types of cues: binocular and monocular. Binocular cues depend on the combination of images from both eyes and how the eyes work together. Since the eyes are in slightly different positions, each eye captures a slightly different image. This disparity between images, known as binocular disparity, helps the brain interpret depth. When the brain compares these images, it determines the distance to an object.