Related Experiment Video

Updated: Aug 4, 2026

Perceptual and Category Processing of the Uncanny Valley Hypothesis' Dimension of Human Likeness: Some Methodological Issues
07:34

Perceptual and Category Processing of the Uncanny Valley Hypothesis' Dimension of Human Likeness: Some Methodological Issues

Published on: June 3, 2013

Contrast discrimination: a model and a hypothesis concerning the role of cholinergic modulation in contrast

A T Smith1

  • 1Department of Psychology, Royal Holloway College, University of London, Egham, Surrey, England.

Visual Neuroscience
|September 1, 1996
PubMed

More Related Videos

Visualizing Visual Adaptation04:43

Visualizing Visual Adaptation

Published on: April 24, 2017

Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments13:00

Measuring Attention and Visual Processing Speed by Model-based Analysis of Temporal-order Judgments

Published on: January 23, 2017

Related Concept Videos

Cholinergic Receptors: Muscarinic01:25

Cholinergic Receptors: Muscarinic

The pharmacological actions of acetylcholine are elicited via its binding to two families of cholinergic receptors or cholinoceptors, namely, muscarinic and nicotinic receptors. Muscarinic receptors are G protein-coupled receptors and have five subtypes, M1–M5. All mAChR subtypes are activated by acetylcholine and blocked by the antagonist, atropine. 
The subtypes M1, M3, and M5 couple with the Gq subunit and activate the phospholipase C (PLC) activity, mobilizing intracellular Ca2+. Activation...
Anatomy of the Eyeball01:20

Anatomy 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,...
Photoreceptors and Visual Pathways01:22

Photoreceptors and Visual Pathways

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, whereas...
Color Vision01:24

Color 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.