Week 9 Flashcards
What are they hemispheres, lobes, and poles of the brain
Hemispheres- left and right
Four lobes- frontal, parietal, occipital, temporal
Three poles- temporal, frontal, occipital
3 major fissures or Sulci
interhemispheric, central, lateral (sylvian)
Sulcus/Sulci
A shallow cleft (groove) in the cortex
-central sulcus, pre-central sulcus, post-central sulcus
Gyrus/Gyri
A ridge (bump) in the cortex
-pre-central gyrus (primary motor cortex), post-central gyrus (primary sensory cortex)
Primary Motor cortex (m1)
Precentral gyrus
-sends efferent motor signal to the spinal motor neuron pool via cortical spinal tract (upper motor neurons)
Pre motor cortex (PMC)
Anterior to precentral gyrus
-receives sensory info from parietal cortex, motor info from basil ganglia and cerebellum, and send signal to M1
-involved in generation or motor command signal
Primary somatosensory cortex (S1)
Postcentral gyrus
-receives tactile, proprioceptive, and kinesthetic info from the periphery (via thalamus)
Primary visual cortex (v1)
Occipital pole
-receives visual info from eyes (via thalamus)
Primary auditory cortex (A1)
Superior temporal gyrus
-receives sound info from ears (via thalamus)
Parietal cortex
Integration of sensory info (visual, tactile, proprioceptive, and auditory) for attention, perception, and action
-damage leads to acquired disorders of attention, visual-motor control, body and spatial awareness
Lateral descending pathways
Serve distal musculature of the hands and feet-involved in fine motor control
Medial descending pathways
Serve proximal musculature of the neck, trunk, shoulders, and hips
-largely involved in controlling gross movements, balance, and gait
Lesion method
If brain area x is involved in motor performance, then damage to x will lead to movement impairment. The nature of the movement impairment may reveal that brain areas role in performance
Decorticate rigidity
Observed when pyramidal tracts are interrupted but extrapyramidal tracts are left intact (de-cortex- input from the cortex is disrupted)
-arms adducted, elbows, wrists, and fingers flexed, legs extended, internally rotated
Decerebrate rigidity (worse)
Observed when both pyramidal and extrapyramidal tracts are disrupted
-arms extended with wrists rotated, legs extended, with fee internally rotated
Activation method
If brain area x is involved in movement performance, the area x will be more active when people perform a movement task than when they perform some other task
Stimulation method
Stimulate a particular region of the cortex by applying a (low-voltage) electrical signal and observe the resulting movement
Transcranial magnetic stimulation (TMS)
A method for stimulating a specific brain area in healthy research participants
What are the 3 aspects of voluntary movement
- Locate target using vision- parietal cortex sends location info to premotor and motor cortex
- Reach- is moving the hand a certain distance and direction (distance and direction are directed by premotor and motor cortex)
- Grasp
Visual Form Agnosia
An inability to use vision to determine shape
Optic Ataxia
An inability to use vision to determine location and size for reaching and grasping
