Related Experiment Video
Updated: Jan 24, 2026
08:42
Monocular Visual Deprivation and Ocular Dominance Plasticity Measurement in the Mouse Primary Visual Cortex
Published on: February 8, 2020
11.2K
Preserved extrastriate visual network in a monkey with substantial, naturally occurring damage to primary visual
Holly Bridge1,2, Andrew H Bell1,3,4, Matthew Ainsworth3,4
1Wellcome Centre for Integrative Neuroimaging, FMRIB, Oxford University, Oxford, United Kingdom.
Elife
|May 24, 2019
Summary
This study examined a Rhesus macaque born without primary visual cortex (V1). Despite intact behavior, visual tasks were impaired, with sparse cortical activation and no evidence of blindsight phenomena.
Area of Science:
- Neuroscience
- Visual System Research
- Primate Studies
Background:
- Primary visual cortex (V1) lesions cause visual perception loss in humans.
- Understanding V1 damage consequences can inform rehabilitation strategies.
- This study investigates a rare case of a Rhesus macaque potentially born without V1.
Purpose of the Study:
- To investigate the neural consequences of V1 absence in a Rhesus macaque.
- To assess visual processing and functional connectivity in the absence of V1.
- To explore potential residual visual function and blindsight phenomena.
Main Methods:
- Multi-modal magnetic resonance imaging (MRI) was used to examine brain structures.
- Functional connectivity analysis was performed to assess neural networks.
- Visual stimulation paradigms (checkerboards, moving dots) were employed under anesthesia.
Main Results:
- The Rhesus macaque showed normal in-group behavior but impaired visual task performance.
- Subcortical structures (lateral geniculate nucleus, pulvinar) responded to visual stimuli.
- Sparse visual cortical activation was observed, including face patches, with an intact dorsal visual area network.
- Little evidence for strengthened subcortical input to V5/MT supporting residual vision was found.
Conclusions:
- The absence of V1 in this Rhesus macaque resulted in impaired visual task performance despite intact subcortical responses.
- Functional connectivity in dorsal visual areas remained intact without V1.
- The findings suggest limited capacity for blindsight-like phenomena or strengthened subcortical input for residual vision in the absence of V1.
Related Concept Videos
01:26Visual System
1.7K
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...
1.7K
01:12Visual Agnosia
1.0K
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...
1.0K
01:32What is Natural Selection?
126.4K
Natural selection is an evolutionary process in which individuals with survival-promoting traits reproduce at higher rates. These favorable traits become more common within a population or species. Naturally selected traits initially arise via random genetic mutations. In order for selection to occur, there must be variation within a population, the trait controlling the variation must be heritable, and there must be an evolutionary advantage for variation in the trait.
126.4K
02:26Protein Networks
4.5K
An organism can have thousands of different proteins, and these proteins must cooperate to ensure the health of an organism. Proteins bind to other proteins and form complexes to carry out their functions. Many proteins interact with multiple other proteins creating a complex network of protein interactions.
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
These interactions can be represented through maps depicting protein-protein interaction networks, represented as nodes and edges. Nodes are circles that are representative of a protein,...
4.5K
01:22Photoreceptors and Visual Pathways
8.9K
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,...
8.9K
02:24Regulation of Expression Occurs at Multiple Steps
25.8K
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
25.8K