What is the Geniculostriate pathway?
geniculostriate pathway (plural geniculostriate pathways) (anatomy) A group of axons that connect neurons in the lateral geniculate nucleus to the primary visual cortex.
What is the Retinotectal pathway?
Thus the retinotectal pathway is involved in orienting the eye toward a stimulus that initially appears in its peripheral field of vision. Like the lateral geniculate nucleus, the superior colliculus also receives connections from the primary visual cortex.
What is the magnocellular pathway?
The magnocellular and parvocellular pathways (M and P pathways) are the major pathways of the visual system, accounting for most of the axons that leave the retina and the perceived vision, as demonstrated by loss of vision when the pathways are destroyed.
What is striate cortex?
The striate cortex is the part of the visual cortex that is involved in processing visual information. The striate cortex is the first cortical visual area that receives input from the lateral geniculate nucleus in the thalamus.
What is the Tectopulvinar pathway?
The tectopulvinar pathway is a fast-acting pathway that provides the viewer with information on the absolute spatial information of objects.
Where is Meyer’s loop?
temporal lobe
The Meyer loop is part of the inferior optic radiation that sweeps back on itself into the temporal lobe, just lateral to the temporal horn of the lateral ventricle. It can be injured in temporal lobectomy, resulting in a superolateral field cut, the so called pie-in-the-sky field cut.
What is Retinotectal projection?
Retinotectal projection is organized in a retinotopic manner and can be manipulated experimentally, so it has been a model system for the study of neuronal circuit formation. Pioneer work was carried out by Sperry (1963).
What is blindsight in the brain?
Summary: Blindsight is a phenomenon in which patients with damage in the primary visual cortex of the brain can tell where an object is although they claim they cannot see it. Scientists now provide compelling evidence that blindsight occurs because visual information is conveyed bypassing the primary visual cortex.
What is the function of magnocellular?
The Magnocellular pathway carries information about large, fast things (low spatial frequency; high temporal frequency) and is colorblind. The Parvocellular pathway carries information about small, slow, colorful things (high spatial frequency information; low temporal frequency information).
Where does the magnocellular pathway begin?
the retina
Definition. The magnocellular pathway is one of the three primary subcortical pathways (magnocellular, parvocellular, and koniocellular pathways) leading from the retina to visual cortex via the lateral geniculate nucleus (LGN).
Why is it called striate cortex?
The name “striate cortex” is derived from the line of Gennari, a distinctive stripe visible to the naked eye that represents myelinated axons from the lateral geniculate body terminating in layer 4 of the gray matter. The primary visual cortex is divided into six functionally distinct layers, labeled 1 to 6.
What is the posterior parietal cortex?
Posterior parietal cortex is a region of the brain that has been implicated in spatial attention and eye movements. In humans, lesions of the parietal lobe cause patients to ignore sensory stimuli located in the contralateral half of space, a phenomenon known as neglect.
What is the tectopulvinar pathway?
The tectopulvinar pathway is a fast-acting pathway that provides the viewer with information on the absolute spatial information of objects.
What is the difference between tectopulvinar and geniculostriate?
The tectopulvinar pathway terminates at the prestriate cortex (also known as the extrastriate cortex or visual area V2), which receives large feedforward input from the striate cortex; the geniculostriate pathway also converges to the same location. .
What are the signs and symptoms of tectopulvinar pathogenesis?
Damage to the tectopulvinar pathway is most commonly characterized by visual ataxia, a deficit characterized by an inability to perform visually guided hand movements in reaching and grasping objects, as well as by spatial attentional deficits.