Related Experiment Video
Updated: Sep 27, 2025
07:12
Development of a Gaze-Contingent Display Framework Designed for Perceptual and Oculomotor Research with Simulated Central Vision Loss
Published on: April 11, 2025
579
Critical Periods in Vision Revisited
Donald E Mitchell1, Daphne Maurer2
1Department of Psychology & Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada;
Annual Review of Vision Science
|April 6, 2022
Summary
Critical periods in the developing visual cortex are crucial for normal vision. Research has shifted from cats and primates to rodents, necessitating a review of past and present findings to guide future animal model selection.
Area of Science:
- Neuroscience
- Developmental Biology
- Ophthalmology
Background:
- For 40 years, critical period research in the mammalian visual cortex focused on cats and nonhuman primates.
- Neural deficits from altered visual experience informed studies on human amblyopia.
- Recent human studies reveal deficits across visual and nonvisual cortical areas.
Purpose of the Study:
- To review human and earlier animal data on critical periods in visual cortex development.
- To infer general conclusions from diverse study models.
- To optimize the selection of future animal models for studying neural mechanisms.
Main Methods:
- Review of existing literature on visual cortex development and critical periods.
- Comparative analysis of findings from studies in cats, nonhuman primates, rodents, and humans.
- Synthesis of data from studies involving altered early visual experience.
Main Results:
- Early visual experience critically shapes the developing visual cortex.
- Deficits extend beyond primary visual areas, affecting broader neural networks.
- A significant shift towards rodent models has occurred in recent research.
Conclusions:
- Integrating findings from primate, feline, and human studies is essential.
- Current rodent models may not fully capture the complexity of human visual development deficits.
- Careful consideration of animal models is needed to advance understanding of critical periods and amblyopia.
Related Concept Videos
01:22Photoreceptors and Visual Pathways
6.6K
At the molecular level, visual signals trigger transformations in photopigment molecules, resulting in changes in the photoreceptor cell's membrane potential. The photon's energy level is denoted by its wavelength, with each specific wavelength of visible light associated with a distinct color. The spectral range of visible light, classified as electromagnetic radiation, spans from 380 to 720 nm. Electromagnetic radiation wavelengths exceeding 720 nm fall under the infrared category,...
6.6K
01:24Color Vision
780
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.
780
01:24Vision
55.5K
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.
55.5K
01:15Depth Perception and Spatial Vision
1.0K
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.
1.0K
01:20Anatomy of the Eyeball
7.6K
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...
7.6K
01:16Focusing of Light in the Eye
3.3K
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...
3.3K