Related Experiment Video
Updated: Jun 19, 2025
08:32
Large Volume, Behaviorally-relevant Illumination for Optogenetics in Non-human Primates
Published on: October 3, 2017
8.0K
Illusory light drives pupil responses in primates
Jean-Baptiste Durand1,2,3, Sarah Marchand1,2,4, Ilyas Nasres1,2,5
1Université de Toulouse, Centre de Recherche Cerveau et Cognition, Toulouse, France.
Journal of Vision
|July 24, 2024
Summary
Pupil responses to illusory brightness are similar in humans and macaques, suggesting an adaptive mechanism. This phenomenon, linked to visual perception, shows a cyan bias in both species.
Area of Science:
- Neuroscience
- Comparative Psychology
- Visual Perception
Background:
- Human pupils react to both physical light and brain's light perception.
- Pupils constrict to illusory brighter stimuli, even with constant retinal illumination.
Purpose of the Study:
- Investigate if pupil response to illusory brightness is unique to humans or an adaptive trait in other animals.
- Determine if this phenomenon helps anticipate retinal illumination changes between eye fixations.
Main Methods:
- Measured pupil responses in humans and macaque monkeys.
- Used three chromatic versions (cyan, magenta, yellow) of the Asahi brightness illusion.
Main Results:
- Illusory brighter or darker stimuli elicited differential pupil responses in both species.
- Similar pupil responses observed between macaques and humans.
- An analogous cyan bias was present in both primate species.
Conclusions:
- Macaque monkeys are a relevant model for studying perceptual penetrability of pupil responses.
- The phenomenon is likely tuned to ecological conditions, possibly related to risks from bright cyan skies.
Related Concept Videos
01:24Vision
53.1K
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.
53.1K
01:22Photoreceptors and Visual Pathways
6.0K
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,...
6.0K
01:20Anatomy of the Eyeball
6.9K
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...
6.9K
01:26Visual System
564
Light enters the eye through the cornea, a transparent, dome-shaped surface covering the surface of the eyeball that helps to direct and focus incoming light. This light is then channeled toward the pupil, an adjustable opening whose size is controlled by the iris. The iris, a pigmented muscle, regulates the amount of light entering the eye by contracting or dilating the pupil, thereby ensuring optimal light levels for clear vision.
Once through the pupil, the light passes through the lens, a...
Once through the pupil, the light passes through the lens, a...
564