Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Focusing of Light in the Eye01:16

Focusing of Light in the Eye

6.2K
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...
6.2K
Vision01:24

Vision

48.6K
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.
48.6K
Anatomy of the Eyeball01:20

Anatomy of the Eyeball

8.6K
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...
8.6K
Depth Perception and Spatial Vision01:15

Depth Perception and Spatial Vision

2.7K
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.
2.7K
Muscles of the Eye01:20

Muscles of the Eye

6.4K
The muscles of the eye are sophisticated structures that control eye movement and focus, allowing for the precise and rapid adjustments necessary for vision. The human eye is controlled by ten muscles — six extraocular muscles, three intraocular muscles, and one primary eyelid retractor muscle.
Extraocular Muscles
The six extraocular muscles surround the eyeball and control its movements. They are responsible for a wide range of eye motions, including looking up, down, left, right, and...
6.4K
Visual System01:26

Visual System

2.3K
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...
2.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Just noticeable difference thresholds of asynchrony and non-isochrony in a Multi-Instrumental groove-based context.

The Journal of the Acoustical Society of America·2026
Same author

Pupil Size Reflects Trial-Level Variability in Imagery Vividness During Immersive Storytelling but Not (or Hardly) Individual Differences in Trait Imagery.

Psychophysiology·2026
Same author

Music Ensemble: a large dataset on musicianship, cognition, and personality in musicians and nonmusicians.

Scientific data·2026
Same author

Pupil adjustments to illusory perceptions of the light intensity of object surfaces.

Frontiers in human neuroscience·2025
Same author

Dimensions of music use motivations: Genetic and environmental underpinnings, and associations with Big Five and Empathy traits.

PloS one·2025
Same author

Visual short-term memory is modulated by 3D depth in stereopsis.

Attention, perception & psychophysics·2025

Related Experiment Video

Updated: May 5, 2026

Author Spotlight: An Accurate and Quantitative Approach to Study Visual Feature Selectivity of the Optokinetic Reflex in Mice
09:28

Author Spotlight: An Accurate and Quantitative Approach to Study Visual Feature Selectivity of the Optokinetic Reflex in Mice

Published on: June 23, 2023

3.4K

The eye pupil adjusts to imaginary light.

Bruno Laeng1, Unni Sulutvedt

  • 1University of Oslo.

Psychological Science
|November 29, 2013
PubMed
Summary

Pupil size changes reflect the brightness of imagined objects and scenarios, suggesting mental imagery involves brain states similar to perception. This research explores the connection between visual perception and mental imagery.

Area of Science:

  • Cognitive Neuroscience
  • Psychology of Perception
  • Visual Cognition

Background:

  • Mental imagery is theorized as a re-representation of perception.
  • Perceptual properties like luminance should be present in mental images if this theory holds.

Purpose of the Study:

  • To investigate if mental imagery of varying luminance and complexity affects pupil diameter.
  • To explore the neural basis of mental imagery by comparing it to perceptual processes.

Main Methods:

  • Pupil diameter was monitored using an infrared eye tracker.
  • Participants viewed and then mentally generated images of shapes with different luminances and complexities.
  • Participants also imagined familiar scenarios of varying brightness.
Keywords:
attentionimageryperceptionpupillometryvision

More Related Videos

Gaze in Action: Head-mounted Eye Tracking of Children's Dynamic Visual Attention During Naturalistic Behavior
07:09

Gaze in Action: Head-mounted Eye Tracking of Children's Dynamic Visual Attention During Naturalistic Behavior

Published on: November 14, 2018

10.4K
Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects
07:36

Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects

Published on: November 30, 2018

16.6K

Related Experiment Videos

Last Updated: May 5, 2026

Author Spotlight: An Accurate and Quantitative Approach to Study Visual Feature Selectivity of the Optokinetic Reflex in Mice
09:28

Author Spotlight: An Accurate and Quantitative Approach to Study Visual Feature Selectivity of the Optokinetic Reflex in Mice

Published on: June 23, 2023

3.4K
Gaze in Action: Head-mounted Eye Tracking of Children's Dynamic Visual Attention During Naturalistic Behavior
07:09

Gaze in Action: Head-mounted Eye Tracking of Children's Dynamic Visual Attention During Naturalistic Behavior

Published on: November 14, 2018

10.4K
Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects
07:36

Eye Tracking During Visually Situated Language Comprehension: Flexibility and Limitations in Uncovering Visual Context Effects

Published on: November 30, 2018

16.6K

Main Results:

  • Pupil diameter dilated or constricted in response to imagined dark or bright objects/scenarios, respectively.
  • Increased shape complexity independently increased mental effort and pupil size, irrespective of luminance.
  • Pupillary adjustments occurred even though participants could not voluntarily control them.

Conclusions:

  • Observed pupillary responses to imagined light provide strong evidence for mental imagery relying on brain states similar to perception.
  • This study supports theories of mental imagery as a process grounded in perceptual brain mechanisms.