Related Experiment Video
Updated: May 21, 2026
06:25
Stereoacuity Improvement using Random-Dot Video Games
Published on: January 14, 2020
Stereoacuity in the periphery is limited by internal noise
Susan G Wardle1, Peter J Bex, John Cass
1School of Psychology, The University of Sydney, Sydney, New South Wales, Australia. swardle@psych.usyd.edu.au
Journal of Vision
|June 12, 2012
Summary
Depth discrimination is sharper in the fovea than the periphery. Increased internal noise, not reduced sampling efficiency, limits peripheral depth perception, especially at higher disparity noise levels.
Area of Science:
- Vision Science
- Perceptual Psychology
Background:
- Depth discrimination is known to be more precise in the fovea compared to the visual periphery.
- Understanding the factors limiting peripheral depth perception is crucial for visual science.
Purpose of the Study:
- To investigate the decline in depth discrimination thresholds with increasing eccentricity from the fovea.
- To differentiate the roles of internal noise and sampling efficiency in peripheral depth discrimination using an equivalent noise analysis.
Main Methods:
- Participants discriminated the mean depth of "dead leaves" stimuli with varying ellipse properties.
- Disparity noise levels ranged from 0.05 to 13.56 arcminutes.
- Stimuli were presented at visual field locations from 0° to 9° eccentricity.
Main Results:
- Depth discrimination thresholds were lower in the fovea than the periphery at low disparity noise levels.
- At higher noise levels (>3.39 arcmin), foveal and peripheral thresholds converged.
- Equivalent noise model parameters indicated increased internal noise, not decreased sampling efficiency, limits peripheral performance.
Conclusions:
- Peripheral depth discrimination is primarily limited by increased internal noise, not by reduced sampling efficiency.
- A loss of precision in early visual processing of local disparity information underlies impaired fine depth discrimination in the periphery.
Related Concept Videos
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,...
01:21Perceiving Loudness, Pitch, and Location
The human brain perceives pitch through two primary mechanisms reflected in place theory and frequency theory. Each mechanism describes how sound waves are interpreted as specific pitches by the brain, offering insights into the intricate processes of auditory perception.
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying...
Place theory, or place coding, suggests that different pitches are heard because various sound waves activate specific locations along the cochlea's basilar membrane. The brain determines the pitch of a sound by identifying...
01:05Difference from Background: Limit of Detection
The limit of detection (LOD) is the smallest amount of analyte that can be distinguished from the background noise. The LOD value corresponds to the concentration at which the analyte signal is three times larger than the standard deviation of the blank signal. Below this value, the analyte signal cannot be differentiated from the background noise. It is calculated by dividing the calibration slope by 3 times the standard deviation of the blank signals.
The LOD indicates the presence or absence...
The LOD indicates the presence or absence...
01:17Auditory Perception
The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a...
01:01Perception of Sound Waves
The human ear is not equally sensitive to all frequencies in the audible range. It may perceive sound waves with the same pressure but different frequencies as having different loudness. Moreover, the perception of sound waves depends on the health of an individual's ears, which decays with age. The health of one's ears may also be affected by regular exposure to loud noises.
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...
The pitch of a sound depends on the frequency and the pressure amplitude of the source. Two sounds of the same frequency...
00:50Unrenewable Cells
In humans, the photoreceptor cells of the eye and sensory hair cells of the ear lack stem cells. These cells are thus unrenewable and cannot be replaced when they are damaged or destroyed.
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...