The Occipital Lobe Flashcards Preview

PSYCO 377 > The Occipital Lobe > Flashcards

Flashcards in The Occipital Lobe Deck (19):

What is the dorsal stream?

-The where/how stream
-Visual guidance of movements


What is the ventral stream?

-The what stream
-Object perception (including colour)


What are the five categories of vision?

-Vision for action (parietal visual areas in dorsal stream; reaching, ducking, catching)
-Action for vision (visual scanning, eye movements and selective attention)
-Visual recognition (temporal lobes; object recognition)
-Visual space (parietal and temporal lobes; spatial location)
-Visual attention (selective attention)


What is monocular blindness?

-Loss of vision in one eye
-Results from destruction of retina or optic nerve


What is bitemporal hemianopia?

-Loss of vision from both temporal fields (lateral vision)
-Results from lesion to medial region of the optic chiasm


What is nasal hemianopia?

-Loss of vision of one nasal field
-Results from lesion of the lateral chiasm


What is homonymous hemianopia?

-Blindness of one entire visual field
-Results from a complete cut of the optic tract
-Damage to LGN or V1


What is macular sparing?

-Results from lesion to occipital lobe
-Sparing of central or macular region of visual field
-Differentiates lesions of optic tract or thalamus from cortical lesions
-Macular sparing occurs only after lesions to the visual cortex


What is quadrantanopia of hemianopia?

-Results from lesion to the occipital lobe
-Complete loss of vision of one-quarter or one-half of the fovea


What are field defects?

-Scotomas - small blind spots
-Results from small lesions to occipital lobe
-Visual system is good at overcoming these blind spots


What is blindsight?

-Perception of motion and location without perceiving content


What is visual form agnosia?

-Inability to recognize line drawings of objects
-Bilateral damage to LO region and tissue between parietal and occipital lobes


What is optic ataxia?

-Deficit in visually guided hand movements
-Bilateral hemorrhages in occipito-parietal regions


Prosopagnosia is caused by a lesion in which brain area?

-Right occipito-temporal lesion


Alexia is caused by a lesion in which brain area?

-Left occipito-temporal lesion


What is apperceptive agnosia?

-Deficit in ability to develop percept of an object of objects
-Can describe components of object but cannot say what the whole thing is
-Bilateral damage to lateral parts of occipital lobes


What is simultagnosia?

-Unable to perceive more than one object at a time


What is associative agnosia?

-Can perceive objects, but cannot identify them
-No memory of objects
-Lesions to anterior temporal lobes


Damage to what area causes alexia? What agnosias is alexia a form of?

-Damage to left fusiform and lingual areas
-Form of object agnosia (inability to construct perceptual wholes from parts) OR
-Form of associative agnosia (word memory is damaged or inaccessible)