occipital lobe Flashcards
staining of this cortical area has discovered blobs and interblobs
- -> colour perceptions =
- -> form and motion perceptions=
primary visual cortex
- blobs
- interblobs
you need to make sense of these 3 things to understand the world
colour, motion and form
the primary visual cortex receives input from the?
lateral geniculate nucleus (LGN)
the ? sends output to all other occipital areas
primary visual cotrtex
staining of this visual areas has discovered stripes
- -> thin stripes =
- -> thick and pale stripes =
secondary visual cortex
- colour perception
- form and motion perceptions
what visual stream is involved in visual guidance of moving for grasping (knowing where we are in space)
dorsal stream
what visual stream has neurons that take part in converting visual info into coordinates (where to move hand when grabbing something)
dorsal stream
what visual stream is involved in object perception (know what an object is)
ventral stream (inferior temporal cortex)
what visual stream is involved in biological and body movements (facial expressions, social gestures, recognition of movement)
ventral stream (superior temporal cortex)
V4 damage leads to
loss of colour cognition
- cannot see, imagine, recall or think about colour
V5 damage leads to
erases a persons ability to see objects in motion (can only see them when they are at rest)
V3 damage and larger legion of V4 damage results in
deficit in form perception
people are cortically blind when they have lesions to ?
V1
2 forms of visual processing
- visual space
- visual attention
egocentric space is which type of visual processing and is necessary for what and is in what lobe
visual space
- objects relative to self
- necessary for controlling action towards objects
- parietal lobe
allocentric space is which type of visual processing and is necessary for what and is in what lobe
visual space
- objects relative to one another
- necessary for visual recognition
- temporal lobe
we focus our attention on specific aspects of visual information, rather than processing all info. This is what type of visual processing
visual attention
right half of each retina sends projections to the ? side of the brain
left
areas of the visual field are topographically represented in ?
V1 (specific damage affects specific area of visual field)
- failure of making sense of information (not receiving it)
- failure of recognition
- not explained by sensory deficits
- not a deficit in recall but in recognition
agnosia
-Failure of object recognition in which basic visual functions (acuity, color, motion) are preserved lobe
apperceptive agnosia
unable to recognize a percept of the object, cannot copy, recognize and match shapes
apperceptive agnosia
apperceptive agnosia results from damage to the ?
gross bilateral damage to the occipital lobe
inability to recognize an object despite its apparent perception
- can copy an item correctly but not identify it
- cant associate it to what we have seen in the past
associative agnosia
associative agnosia results from damage to the ?
ventral stream (anterior ventral)
agnosia where you appear bling at times (not taking in and making sense of info)
apperceptive
agnosia where you have an inability to combine individual aspects of visual info to form a percept
apperceptive
agnosia where you have a loss of knowledge of semantic meaning of objects
association
agnosia where you cant recognize faces
- damage to the ?
prosopagnosia
- fusiform area
agnosia where you are unable to perceive a whole (words) from a part (letters)
-damage to the?
alexia
- left fusiform and lingual areas
