Movement Psy 445 w01
I. Functions of motor systems
 A. producing stable posture
 B. producing useful movements
 C. complexity of even apparently simple movements
 D. connections and function of brain regions involved in movement
II. Overview-much is automatic.  You don’t know which muscles to contract.
 A. frontal cortex-plan goal directed movements
 B. parietal cortex
 C. supplementary and premotor cortex
 D. primary motor cortex
 E. basal ganglia
 F. cerebellum
 G. spinal cord
III. brain control of complex movements-function of structures involved in movement.
 A. posterior parietal cortex: where you are relative to thing you want to move toward or away from. Collect sensory inputs. Send to frontal cortex.
 B. premotor and supplementary motor cortex plan sequence of muscle  movements.
  1. effects of lesions
  2. tasks that require planning cause increased blood flow in premotor ctx.
 C. primary motor cortex determines  which muscles will be active and how much force they will exert.
  1. the pathway from primary motor cortex to motorneuron
   a. mapping
   b. corticospinal tract has both monosynaptic pathway to motor neurons as well as multisynaptic pathway to spinal cord.
  2. voluntary control of individual motor units
  3. What do single units code?
   a.  force
   b. direction.
  4. effect of lesions
   a. loss of skilled movements
   b. increased reaction time
   c. causes clumsiness
   d. weakness of movement, especially in hands
 D. cerebellum: timing of muscle contractions.  Timing and motor learning depend on cerebellum.  Motor learning depends on timing, must contract muscles in the right order.
 E. basal ganglia: important in amplitude and direction of movement but not well understood.  May have functions other than motor functions.
  1. May also be important in regulating muscle force. Basal ganglia pts cannot learn to regulate force.