Lernmaterialien für Motor Systems an der University of Amsterdam

 higher motor areas -> complexity and efficiency of behavior

-> monitored & modulated by 2 key motor systems:

• the cerebellum
  • corrects errors in ongoing movements and learn new motor skills

• the basal ganglia
  • gates motor commands and facilitates simple forms of learning

Apraxia 

= cant execute learned voluntary movements ( esp. complex sequences of movements) despite motivation & physical capability

Ideomotor apraxia = 

• inability voluntarily perform learned action when presented with the appropriate objects
• or inability to imitate what someone else is doing
• or inability to follow verbal instructions (e.g. waving goodbye, combing hair on command)

= cant carry out sequential tasks involving tools or objects in the proper order (e.g. putting shoes on before putting on socks)

1. highest level: motor programmes = sets of commands to initiate a sequence of movements

• ballistic = do not strictly depend on incoming sensory information

2. Intermediate processing levels:

•  translate motor programs into 
  • coordinated sequences of motor neuron activation
  • suppression that are responsible for muscle contraction & relaxation

3. Lowest level = elementary behavioral units ->  directly activate muscles

1.SMA,  Premotor, Prefrontal

• Goals and planning of sequences of movement 

2. Motor cortex (M1)

• partially involved in planning of movement
• partially in activating specific groups of muscles 

3. Basal ganglia

• Selecting and inhibiting motor actions
• simple learning 

4. Cerebellum: Adjusting ongoing movements 

5. Brainstem

• Relaying motor signals
• Adjusting posture 

6. Spinal cord

• direct activation of single muscle fibers 
• reflexes

supplementary motor cortex

Planning of learned sequences of movement

Example: Playing guitar when you have already mastered it

Posterior Parietal Cortex

-> computations for location based movement, grasping, reaching (scissors, cut, keys, open doors)

• Complex muscle movements
  • control over muscles in trunk & proximal muscles (close to trunk)

• Learning sequences of motor actions
  • external cues (sensory info) is required
  • looking and listening to your guitar teacher when repeating a played sequence

• Brocas region: directed to speech output

-> Partially involved in planning of movement

->  partially in activating specific (groups of) muscles 

-> direction based movement