ch 14 parietal lobes Flashcards
the parietal lobes
process and integrate somatosensory and visual info–what you feel with what you see, movement control
anatomy of parietal lobes
anterior border-central fissure ventral border-sylvan fissure dorsal-cingulate gyrus posterior-parietooccipital sulcus between frontal and occipital lobes, under parietal bone at skull roof
anterior zones process
somatic sensations and perceptions
posterior zones integrate
info from vision with somatosensory info for movement control (important to see to move)
use of spatial info: object recognition
viewer centered object indentification(where you are in space)–location, location orientation, and motion of an object
make computations everytime new movement made
brain operates on need to know basis
object centric-object compared to object
use of spatial info: guidance of movement
sensitive to eye movement, posterior parietal cortex, visuomotor guidance, cells detect visual ifo then move eye to examine it
dorsal stream-spatial processing
use of spatial info: sensorimotor transformation
neural calculations of relative position of the body with respect to sensory feedback from movements being made and planned
monkeys planned movement activity matched actual performance activity
spatial navigation requires
cognitive spatial map-route knowledge to reach destination and medial parietal region-neurons show responses associated with making specific movement at specific locatoin
3 symptoms of damage don’t fit visuomotor view of parietal lobes
acalculia, language, movement sequencing
lesions to postcentral gyrus produce
abnormally high sensory thresholds, impaired position sense, deficits in stereogenisis/tactile perception, afferent paresis
somatoperceptual disorders-asterognosis
inability to recognize object by touch
somatoperceptual disorders-simultaneous extinction
2 stimuli applied simultaneously to opposite sides of body, failure to report stimulus on side with lesion (extinction)
somatoperceptual disorders-blind touch
cannot feel stimuli, but can point to location
somatoperceptual disorders-asomatognosia
type of agnosia, loss of knowledge or sense of one’s own body, tactile perception disorder
somatoperceptual disorders-anosagnosia
type of agnosia, unawareness or denial of deficits
somatoperceptual disorders-anosodiaphoria
type of agnosia, indifference to deficits
somatoperceptual disorders-asymbolia for pain
type of agnosia, absence of normal pain reactions
somatoperceptual disorders-finger agnosia
type of agnosia, unable to point to fingers, show correct one
symptoms of posterior damage-balint’s syndrome
can’t fixate of visual stimulus, neglect of objects, optic ataxia (inability to guide hand to object using visual info)
bilateral lesions-full visual fields, could recognize, use and name objects pics and colors
move eyes 35-45 degrees to the right not fixating on specific stimuli
noticed 1 object at a time (simultagnosia)
reaching under visual guidance (visual ataxia)
symptoms of posterior damage-contralateral neglect
most often L neglect, neglect for visual, auditory, ans somesthetic stimulation
lesion mostly in R inferior lobe (intraparietal sulcus and angular gyrus)
during recovery patients go through allesthesia, respond to neglected stimuli as if it were on the other side of the body then simultaneous extinction
lesion to frontal lobe and cingulate cortex
defective sensation/perception
defective attention/orientation
symptoms of posterior damage-object recognition
r pari lesion, poor at recognizing objects in unfamiliar views
symptoms of posterior damage-Gerstmann Syndrome
finger agnosia, R-L confusion, agraphia, acalculia, L pari lobe lesion
L stroke-finger agnosia, R-L confusion, agraphia, acalculia
L lesion-angular gyrus-gerstmann syndrome not accurate
other L parietal symptoms-disturbed language functions
broca’s, wernickes,
other L parietal symptoms-apraxa
movement disorder in which loss of movement not caused by weakness, inability to move, intellectual deterioration/poor, loss of skilled movement
ideomotor-can’t copy serial movemelts, L lesions
constructional-cant copy pics, build puzzles, copy facial movements, L/R lesions
other L parietal symptoms-
dyscalculia, poor recall, inability to discriminate L from R, R hemianopia
symptoms of posterior parietal lobe
deficits in drawing (R), spatial attention
disorders of spatial cognition
mental rotation requires mental imaging of stimulus (L) and manipulation of image
principle regions
postcentral gyrus, superior parietal lobule, parietal operculum, supramarginal gyrus, angular gyrus
supramarginal and angular gyri=inferior parietal lobe
specifical parietal lobe regions take part in ____ stream of ____ processing
dorsal, visual
saccades
series of involuntary, rapid, small movements or jerks that are made by both eyes simultaneously in changing fixation point
drawing deficits
worse with R hemisphere damage,
drawings with L hemi damage less recognizable, less lines
R hemi omits left side details and rotates image
somatosensory threshold test
postcentral gyrus lesions-threshold increases on contralateral side
2 point discrimination test
tactile form recognition test
manipulate shapes in holes then draw from memory
no certain lesion location
contralateral neglect test
line bisection test (mark middle of 20 lines)
those with neglect miss L side
visual perception test
series of incomplete faces/objects presented, combine and identify (mooney closure/golin incomplete figures)
sensative to damage at R parietotemporal junction, ventral visual stream
spatial relations test
l/r differentiation tests-body parts presented at different orientations, indicate which side of body L pari (and frontal) damage
language test
token test-4 shapes in 5 colors in front of person, touch 1 at a time then multiple, can read instructions aloud then follow
temporal speech related
apraxia test
kinura box test-push button with index fingers, pull handle with 4 fingers, press bar with thumb
apraxics perform poorly
