Motor Control

Question 1

Motor Control:

Answer 1

Understanding the neural, physical, and behavioral aspects of human movement.

Question 2

Information Processing:

Answer 2

Human movement occurs in stages:

• Stimulus identification
• Response selection stage
• Response programming
• Response-response compatibility
• Response execution
• This is simplified version of a complex system of info in the CNS. The involvement of the UMN (descending pathways including all the tracts including the selected examples from neuroanatomy) and the LMN (peripheral nerves that activate mm fibers in motor units from the ventral horn of the spinal cord) all combine to give rise to this process.

Question 3

Stimulus identification:

Answer 3

1st stage, relevant stimuli is identified

• Relevant sensory input is based on the clarity and intensity of the input
• Processing the perceived input ( using pattern, complexity, etc.) with memory improves identification of the stimulus.

Question 4

Response Selection stage:

Answer 4

Develop a movement plan

• Motor plan: component motor programs for an idea of purposeful movement
• Not detailed yet, a general response, different movement alternatives are still possible.

Question 5

Response Programming Stage:

Answer 5

Last stage, movement ideas are changed into muscular action through neural control centers

• Coordinated movement sequences are initiated from motor programs (translating, structuring, and initiating)
• Movement output is now organized in respect to complexity, duration, and the compatibility of the response to the stimulus

Question 6

Response-response compatibility Stage

Answer 6

Compatibility for dual movements (i.e. chewing bubble gum and kicking a ball)

Question 7

Response execution stage:

Answer 7

Movement output occurs:

• Feedforward: anticipating future movement needs and getting the bodies systems ready for a movement output.
• Feedback:using sensory information from movement outputs to produce a correlated response to the task at hand, either error corrections or maintenance of the existing motor plan.

Question 8

System Theory:

Answer 8

The brain and spinal centers work in conjunction to execute movement.
-Distributed model of control
-Degrees of freedom
Hierarchical Theory
-Ecological model or task oriented approach

Question 9

Distributed Model of control:

Answer 9

Forces that influence the body’s ability to produce movement, joint stiffness, inertia from mm force, etc. (internal factors) and the force of gravity (external factors) combine to shift the needs of neural control.

Question 10

Degrees of freedom:

Answer 10

Multilevel control systems allowing for independent dimensions of movement ( i.e. central pattern generators (CPG’s able to produce motor production even without motor sensory input) in the spinal cord for movement coordination.
-In other words larger CNS movements for complex tasks can be carried out while smaller less complex activities can be performed with little to no cortex involvement.

Question 11

Ecological model of task oriented approach:

Answer 11

More Recent) movements and actions are influenced or constrained by the environment.

a. Environment is needed to shape how movement occurs to achieve specific actions or tasks
b. Previous approaches viewed the individual as the whole and only sensory-motor system that produces movement, this theory maintains that sensation is not he only participant in a programed response
c. It is the perception of the environmental factors and sensory input that guide the goal- directed task i.e. the taub monkeys
d. Individuals are viewed as organizing desired tasks within the environment that the task is being performed
e. this theory has become more widely accepted by researchers and clinicians.

Question 12

Coordinative structures:

Answer 12

Based on motor programs (biological process that when initiated, consciously or unconsciously, produces a sequence of coordinated movements) that allow movement without sensation, are effective when the speed needed for processing negate control, and can free the need for conscious decisions which reduces the problem of multiple degrees of freedom.

• Open- loop system:
• Closed-loop control system

Question 13

Open-loop system

Answer 13

motor programs that run without sensory feedback or the need for error detection. i.e. playing the guitar so fast sensory feedback is useless.

Question 14

Closed-loop control system:

Answer 14

Use of feedback and sensory input to compute errors and change motor programs to correct movement.

Question 15

Hierarchical Theory:

Answer 15

Older motor control theory, states that the cortex is always in control and only flows from higher to lower centers
~The nervous system would inhibit movements as they progress down the tracts to refine the desired motor program, higher centers ultimately remain in control.

Question 16

Intermittent Control Hypothesis:

Answer 16

Idea that one model cannot encompass the complexity of human movement control.

• Schmidt and Lee combined the open closed-loop control system
• Called Schema Theory: or motor programs that provide generalized actions for movement rather than the brain storing every specific movement, formed as a relationship that is associated with experience
• Feedback is used to refine the perfect motor movement
• Either can be dominant
• Both can operate but with different functions.