Week 6: Visual Lesions Flashcards
Visual Degrees of Fovea
Central 1 to 2 degrees
Visual Degrees of Macula
Central 5 degrees with high visual acuity
Meyer’s Loop Location
Loops forward into the temporal lobe near the inferior horn of the lateral ventricle
Meyer’s Loop Information
From inferior retina and superior visual fields
Upper Optic Radiation Location
Up and under the parietal lobe
Upper Optic Radiation Information
From superior retina and inferior visual fields
Lower Optic Radiation Destination
Lingula
Upper Optic Radiation Destination
Cuneate Gyrus
About half the fibers from the optic nerve and half the cells in the primary visual cortex deal with information from where?
The fovea
Some optic tract fibers bypass the lateral geniculate nucleus and travel through where?
The brachium of superior colliculus
Retinogeniculostriate Pathway Purpose
Visual discrimination and perception
Retinotectopulvinarextrastriate Pathway Purpose
Visual attention and orientation
Dorsal Visual Processing Pathway Destination and Purpose
Parietooccipital association cortex for motion and spacial relationships
Ventral Visual Processing Pathway Destination
Occipitotemporal association cortex and form recognition
Cause of Cortical Blindness
Bilateral damage to primary visual cortex
Visual Anosognosia Feature
Patients are unaware of their deficit
Visual Anosognosia Cause
Cortical blindness
Inferior Occipitotemporal Cortex Damage Can Cause the Following
Prosopagnosia, Achromatopsia, Micropsia and Macropsia
Lesion of Damage in Prosopagnosia
Bilateral fusiform gyrus
Achromatopsia
central disorder of color perception
Prosopagnosia
Inability to recognize faces
Micropsia and Macropsia
Objects appear unusually small or large
Area of Damage in Bilant’s Syndrome
Dorsolateral parietooccipital cortex
Bilant’s Syndrome Components
Simultanagnosia, Optic Ataxia, Occular Apraxia
Simultanagnosia
Impaired ability to perceive parts of a visual scene as a whole
Optic Ataxia
Inability to reach for or point to objects in space under visual guidance
Ocular Apraxia
Difficulty voluntarily directing one’s gaze towards an object in the periphery through saccades
Extrageniculate Pathway Main Purpose
Pupillary response to light
