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

Visual Agnosia01:12

Visual Agnosia

Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round end"...
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...
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,...
Vision01:24

Vision

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.
Prosopagnosia01:24

Prosopagnosia

Prosopagnosia, also known as face blindness, is the inability to recognize faces. In severe cases, individuals with prosopagnosia may not recognize close family members, including parents and spouses, by their faces. For instance, someone with prosopagnosia might walk past their child in a crowd, only realizing their mistake upon noticing their child's distinctive backpack or favorite jacket. Prosopagnosia specifically impairs facial recognition, while the recognition of other objects or...
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.

You might also read

Related Articles

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

Sort by
Same author

CGRP-Targeted Therapy in Vestibular Migraine-How Strong Is the Evidence?

European journal of neurology·2026
Same author

Cup-to-Disc Ratio Is Associated with Disability in Multiple Sclerosis: A Combined OCT and Subjective Visual Vertical Study.

Medicina (Kaunas, Lithuania)·2026
Same author

Investigating the feasibility and acceptability of the TeleRehabilitation of balance clinical and economic Decision Support System (TeleRehaB DSS) in adults at risk of falls: study protocol for a multicentre clinical trial.

BMJ open·2026
Same author

Editorial: Mechanisms of functional dizziness: a window for understanding space-motion cognition.

Frontiers in neurology·2026
Same author

Down-sloping high-frequency audiometric findings in ENT-MS-12 auditory screen-positive patients with relapsing-remitting multiple sclerosis: A pilot case series.

Multiple sclerosis and related disorders·2026
Same author

Communication, expectancy, and placebo response in clinical trial design.

The lancet. Psychiatry·2026

Related Experiment Video

Updated: Jun 9, 2026

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration
10:14

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration

Published on: May 26, 2023

Abnormal visual phenomena in posterior cortical atrophy.

Sebastian J Crutch1, Manja Lehmann, Nikos Gorgoraptis

  • 1Dementia Research Centre, Department of Neurodegeneration, UCL Institute of Neurology, University College London, UK. crutch@dementia.ion.ucl.ac.uk

Neurocase
|September 7, 2010
PubMed
Summary
This summary is machine-generated.

Posterior cortical atrophy (PCA) can cause unusual visual disturbances like prolonged afterimages and illusory motion. This case study investigates these rare symptoms to better understand PCA

More Related Videos

Functional Magnetic Resonance Imaging (fMRI) of the Visual Cortex with Wide-View Retinotopic Stimulation
07:11

Functional Magnetic Resonance Imaging (fMRI) of the Visual Cortex with Wide-View Retinotopic Stimulation

Published on: December 8, 2023

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes
06:25

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

Published on: February 23, 2024

Related Experiment Videos

Last Updated: Jun 9, 2026

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration
10:14

Ex Vivo OCT-Based Multimodal Imaging of Human Donor Eyes for Research into Age-Related Macular Degeneration

Published on: May 26, 2023

Functional Magnetic Resonance Imaging (fMRI) of the Visual Cortex with Wide-View Retinotopic Stimulation
07:11

Functional Magnetic Resonance Imaging (fMRI) of the Visual Cortex with Wide-View Retinotopic Stimulation

Published on: December 8, 2023

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes
06:25

Motion-Acuity Test for Visual Field Acuity Measurement with Motion-Defined Shapes

Published on: February 23, 2024

Area of Science:

  • Neuroscience
  • Ophthalmology
  • Gerontology

Background:

  • Posterior cortical atrophy (PCA) is a neurodegenerative condition.
  • Individuals with PCA often experience complex visual disturbances.
  • These visual symptoms are frequently under-recognized and atypical.

Observation:

  • A single patient with PCA (CRO) exhibited prolonged color afterimages.
  • CRO reported perceived motion of static stimuli and difficulty reading large letters.
  • The patient also experienced a room tilt illusion, a novel symptom in PCA.

Findings:

  • Prolonged afterimages may result from spared V1 inhibitory interneurons.
  • Perceived motion suggests impaired magnocellular pathway function.
  • Difficulty with large letters indicates a reduced visual field; room tilt suggests visual-vestibular integration issues.

Implications:

  • This case highlights the heterogeneous and often unrecognized visual symptoms in PCA.
  • Understanding these symptoms aids in diagnosing and managing PCA.
  • Further research is needed to elucidate the neural mechanisms underlying these visual phenomena.