Parietal Lobe
posterior zone of parietal lobe
all areas between the post-central gyrus and parieto-occipital sulcus
ventral posterior nucleus
area in the thalamus where somatosensory information is sent via the spine
Balint's syndrome cause
bilateral damage to the parietal lobe
proprioceptive system
body position/movement
somatosensation reception
contralateral
left parietal apraxia
coordination of limb location and distance to reach objects is impaired in both hands
decussation
crossing over
cause of tactical agnosia
damage in posterior region of the parietal lobe
cause of limb apraxia
damage to left parietal cortex, corpus callosum, or frontal lobe
sympathetic limb apraxia
damage to primary motor are which causes complete right arm paralysis and poor left arm movement
hemispheric neglect cause
damage to the parietal lobe
ideational apraxia
difficulty in performing actions (ie using tools properly)
ideomotor apraxia
difficulty in simulating actions (ie demonstrating how to play tennis)
test for constructional apraxia
drawing tasks - drawings are scattered and fragmented, loss of spatial relations, person is overly-energetic and impulsive while drawing
three interactive systems of somatosensation
exteroceptive, proprioceptive, and interoceptive
secondary somatosensory cortex
helping primary somatosensory cortex in initial processing of touch
Balint's syndrome characterisits
inability to perceive the whole visual field, inability to move your hand to an object using vision, difficulty in fixating the eyes
tactical agnosia
inability to recognize touch
schizophrenia relation to parietal
information from the parietal lobe is sent to the temporal lobe which deals with auditory and visual hallucinations
primary somatosensory cortex
initial processing of sense of touch
interoceptive system
internal conditions like temperature and body chemistry
apraxia
loss of action; patient can perform actions but actions are unorganized and inappropriate - affects motor planning
contralateral neglect
lost ability to respond to stimuli in the visual field contralateral to the damaged hemisphere
limb apraxia
movement in wrong limb, incorrect movement in right limb, sequence of movements is incorrect
constructional apraxia
movement is not impaired but the ability to assemble an object or an image is, mental imagery impaired
primary motor cortex
muscle movement
dorsal root ganglion
nodule in the spin that contains nerves that cary sensory info to the brain, starting point for sensory information
not apraxia when
paralysis, primary sensory problems, muscle weakness, other motor disturbances (such as tremors)
cingulate gyrus
part of the limbic system, responsible for regulation of emotion and pain
parieto-occipital sulcus
posterior region of the parietal lobe and separates the parietal and occipital lobes
post-central gyrus
responsible for somatosensation in parietal lobe, part of the anterior zone of parietal
test for spatial relations using mental imagery
rotation test, drawing of body parts/objects in different rotations, identifying which body part belongs to which side of the body
spinothalamic tract function
sends information to the thalamus about temperature, pain, itch, and crude touch
parietal lobe function
sensory info (especially touch), spatial sense and navigation, manipulating objects, knowledge/manipulation of words/letters/numbers, sends info to decision making areas of the brain
central sulcus
separates parietal and frontal lobes and the primary motor cortex and primary somatosensory cortex
later/sylvian fissue
separates parietal and frontal lobes from the temporal lobe
exteroceptive system
skin
cutaneous sensations
skin sensations
direction of information
somatosensory association cortex, primary somatosensory cortex, auditory/visual cortex in temporal lobe, primary motor cortex, frontal lobe
cortical homunculus
spatial map drawn up by Penfield that shows the divisions of the primary motor cortex and somatosensory motor cortex
line bisection test
test for contralateral neglect; patient checks off lines they are aware of
rotation test
test for spatial relations using mental imagery, ability to rotate 2 and 3 dimensional objects in your mind and see them different ways, activates superior parietal cortex
foam board test
test for tactical agnosia, patient is blindfolded and needs to be able to place objects such as shapes in the correct location on the board, then asked to draw the board
parieto-temporal juncture damage
theory of mind impaired, patients cannot complete images to get the full thing
damage to anterior region of parietal lobe
touch and finger manipulation
somatosensory system functions
touch, temperature, body position, pain
callosal limb apraxia
transfer of info to the right hemi is blocked, so left side movement is affected
two point discrimination test
used to show if there's damage to the parietal lobe - patient is blindfolded and needs to be able to tell if two points of an object touched them or just one
cause of constructional apraxia
usually damage to the right hemisphere
cause of contralateral neglect
usually right hemi, image is processed not seen (patients can pick a world that related to the image flashed even if they ca't see the image)
monkey neglect experiment
we process information in our visual field even if we don't look directly at it, neurons in posterior parietal fire
extinction in neglect
when you can see any stimulus when it is presented by itself but when paired with another similar stimulus and shown together, only one is perceived and one is extinguished
normal people neglect
yes; right side