Term
| Ventral Visual Pathway Blood Supply |
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Definition
| Posterior Cerebral Artery |
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Term
| Dorsal Visual Pathway Blood Supply |
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Definition
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Term
| Posterior Cerebral Artery (PCA) irrigates: |
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Definition
| Ventral Visual pathway, splenium of the corpus callosum (connects occipital lobes of both hemispheres) |
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Term
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Definition
| Visual field deficits, agnosia, alexia without agraphia (disconnection of left and right hemispheres) |
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Term
| Appreceptive visual agnosia |
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Definition
| Inability to recognise shapes and to segregate figure from background |
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Term
| Associative visual agnosia |
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Definition
| Inability to associate visual perception with its meaning, better with photos and context; patients can copy an object and recognise by touch, but still not know what it is when they see it (object agnosia) |
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Term
| Stroke in basal artery before it diverges into the posterior cerebral arteries can cause: |
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Definition
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Term
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Definition
| A type of associative visual agnosia; patients can recognise by touch but not by sight, even though they can draw the unrecognised object. |
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Term
| Unilateral lesions of parietal lobe cause: |
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Definition
| Hemispatial neglect/inattention, especially right lesions |
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Term
| Bilateral lesions of parietal lobe cause: |
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Definition
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Term
| Which lesions are associated with fixation on small details to exclusion of larger picture (trees, not forest)? |
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Definition
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Term
| Which lesions are associated with neglect of on small details and focus on the larger picture (forest, not trees)? |
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Definition
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Term
| unilateral lesions to primary visual cortex (V1) cause: |
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Definition
| Hemianopia/visual field deficit. CAN'T see one side or quadrant of visual field |
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Term
| Hemispatial neglect/inattention |
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Definition
| CAN see on both sides, but doesn't pay attention to one (contralesional) side, especially if any stimulus is also presented on non-neglected (good) side. |
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Term
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Definition
| Simultaneous agnosia with spatial disorientation, caused by bilateral lesions of the posterior parietal lobes or parieto-occipital junction (like those that cause hemispatial neglect) |
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Term
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Definition
| inability to see more than one object at a time (even if they overlap), constriction of visual attention, seen in Balint's syndrome. Not 'tunnel vision' |
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Term
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Definition
| deficit in mentally representing space and directing actions toward objects in the visual scene, seen in Balint's syndrome |
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Term
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Definition
| lack of spontaneous use; CAN use but doesn't do it on their own |
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Term
| What is it like to have Balint's syndrome? |
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Definition
| There is no visual world, objects are disconnected in space, even when you CAN see things, you have no idea where they are and can't reach for them accurately; ranges in severity |
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Term
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Definition
| Can't reach accurately to objects |
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Term
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Definition
| Pineal gland; gets information from retina to regulate sleep-wake cycle, passes to superior colliculus |
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Term
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Definition
| Eyes reflexively move toward a suddenly appearing peripheral signal, moderated by superior colliculus |
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Term
| lateral geniculate nucleus |
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Definition
| Part of thalamus that receives fibers from retina and sends fibers to primary visual cortex (V1) |
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Term
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Definition
| Fissure in occipital lobe; either side of it is V1 (primary visual cortex) |
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Term
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Definition
| can't see one side of visual field, with either eye; caused by lesion to primary visual cortex (V1) or optic radiations |
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Term
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Definition
| the fibers connecting the lateral geniculate nucleus of the thalamus to the primary visual cortex (V1) |
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Term
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Definition
| preservation of the ability to sense motion on the side that a patient has hemianopia; medial temporal gyrus gets information regarding motion from lateral geniculate nucleus (LGN) and is unaffected by the cause of hemianopia (lesion to V1 or optic radiations) |
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Term
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Definition
| cortex receiving myelinated projections straight from LGN which is connected directly to retina; area surrounding calcarine fissure (calcarine cortex) |
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Term
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Definition
| Can't read but can write, what is written makes no sense; disconnection syndrome. Visual system can't access the part of left hemisphere that decodes writing |
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