Chapter 6 Flashcards
Cortical motor system - Primary Motor Cortex
- execution of movements
- somatotopically organized
- directional tuning
- descending projections to the spinal cord
Primary Motor Cortex: Short versus long stimulation
Short stimulation: small movements in an isolated body part
Long duration: specific posture
Premotor Cortex
Plays a role in orienting the body and readying postural muscles for forthcomming movements
- input: posterior parietal cortex
- output: proximal musculature
(PRE - before)
Cross Modal Sensory Integration
Cells in the PMC that showed tuning for positions of visual stimuli relative to body parts
- fire most vigorously at certain directions and distances
Supplementary Motor Area
Involved in high level planning and production of complex movement sequences
Bimanual coordination
Organizing the limbs
Externally guided movements
Depend on external feedback
Internally generated movements
Depend on a stored representation
Areas associated with externally guided movements
Parietal cortex
Premotor cortex
Cerebellum
Why do visual cues help PD patients move?
Can turn a movement that is internally generated become externally guided therefore do not have to rely on the basal ganglia which is not functioning in PD patients
Spatially relevant behavioural intentions
Cells in the parietal cortex become in response to visual stimuli at locations where movements will be made
Function of the posterior parietal cortex
Map multiple representations of space (retinotopic, head-centered, body-centered)
- used to guide many movements
2 Vision Information Pathways
ventral and dorsal
Ventral stream
Occipital lobe to temporal lobe
- object identification: connecting visual stimuli with semantic memory
- the ‘what’ pathway
Dorsal stream
Occipital lobe to parietal lobe (posterior parietal cortex)
- the ‘where’ pathway
