motor learning final

RT increases

- additional elements in a series are added to the action - when more limbs must be coordinated - when the duration of the movement becomes longer when the to-be-produced movement is more complex the RT is longer because more time is required to organize the motor system before the iniation of the action

open loop characteristics

- advance instructions specify the operations to be done - once the program has been initiated the system executes the instructions essentially without modification - no capibility to detect or to correct errors -- no feedback - most effective in stable, predicitble env --- no need for modification

generating skilled movement (requirments)

- muscles to be used in action - order of muscles involved - forces of muscle contraction - relative timing and sequence among these contractions - the duration of each contraction

problems in motor programing theory

-> storage problem - lack of efficiency -> novelty problem - how novel movements are produced in the first place -> relative timing

RT increases when:

1. Addition elements are added to series of movement 2. More limbs must be coordinated 3. Duration of the movement become longer

Open Loop Control System

1. Advance instructions specify the operations to be done, their sequencing, and their timing 2. Once the program has been initiated, the system executes the instructions, essentially without modification 3. There is no capability to detect or to correct errors because feedback is not involved 4. Open loop systems are most effective in stable, predictable environments in which the need for modification of commands is low

Main Roles of Motor Programs

1. Define and issue the command to musculature that determine when, and how forcefully, and for how long muscle are able to contract and which ones are to contract 2. This is to organize the many degrees of freedom of the muscles and joints into a single unit (program) 3. to initiate preliminary postural adjustments necessary to support the upcoming action 4. modulate reflexes to ensure movement is achieved

Model has two ways of operating

1. If the movement is slow or long duration, the control will be dominated by feedback processes 2. If the movement is fast or brief, then the open-loop portions tend to dominate control

Evidence for MP: Inhibition Actions

At what point after starting the processing states that lead to a movement is one committed to making, or at least starting, the action? (Checked swing or stopped movement) Slater-Hammel (1960) found that the "point of no return" occurred 150-170 ms BEFORE the movement began

CPG and reflex response

CPG determines whether and when certain certain reflex pathways can be activated in action - if there is no stimulus then the CPG carries out the action normally

Explain the major difference between the concept of a motor program and a central pattern generator.

CPG relates more to genetically defined activities such as locomotion, chewing, and breathing, whereas the motor program involves learned activities such as throwing and kicking.

____________ is a centrally located control mechanism that produces genetic, repetitive actions; it is similar to a motor program and triggered by some stimulus and seems to use patterns for activation.

Central pattern generator

When explaining the concept of how novel tasks are learned, what is the major difference between a motor program and a generalized motor program?

Motor program explains how people control coordinated movements by emphasizing the role of prestructured motor commands organized at the executive level but does not account for novel tasks. Generalized motor program suggests that there is a stored pattern of movement instead of a specific movement; it allows flexibility to modify the generalized program to produce various patterns to meet the demands of the task.

List the major characteristics of an open-loop control system.

Preplanned instructions specify the functions to be preformed, including sequencing and timing. Once the program is initiated, the system carries out the instructions with little or no modifications. There is no capability for detecting or correcting errors because feedback is not being used.

startled reactions

RT can be dramatically shortened when startled - initiated faster than can be accounted for by voluntary responses

Evidence for MP: Startle RT

RT can be shortened dramatically when we are startled--fight or flight response Movements (protective) after being startled occur faster than could be initiated by voluntary responses to a stimulus

____________ refers to the time that lapses from the presentation of an anticipated stimulus to the beginning of a person's response; it provides evidence for motor programs.

Reaction time (RT)

Motor Program

a pre-structured set of movement commands that defines and shapes a movement

Bernstein's dynamical perspective explains how motor programs are developed and can be described by all of the following except

is the result of much practice

response complexity

any added time for the movement does not contribute directly to RT RT is affected by the complexity of the movement to be performed during the movement programming stage -- RT increases with increasing complexity

surface features

aspect that allows for changes in movement from time to time. By modifying these parameters we can change HOW the movement is executed

Match the following terms to the correct definitions.

central pattern generator = Thought to control genetically defined, repetitive actions generalized motor program = Defines a flexible pattern of movement rather than a specific action degrees of freedom = These are managed more effectively by skilled performers than by unskilled performers d. movement time = This factor often dictates the type of control (e.g., closed loop or open loop) needed effector = Component of a control system that carries out the desired action surface feature = Changeable component of a movement, also referred to as a parameter discrete skill = An action that is usually brief

This type of control system uses feedback and error detection and correction to maintain the desired state; it is used to control slow, deliberate movements.

closed-loop control

Which system is used while driving a car along the highway in light traffic?

closed-loop control

Which system is used while running a mile?

closed-loop control

GMP

consists of a stored pattern, but one that could be adjusted at the time of movement execution, allowing the action to be changed slightly to meet the current demands. Some are the same, others are variant

deafferentation

cutting a nerve bundle where they enter the cord - CNS can no longer receive information form some of the periphery - motor pathways are not affected (pass through ventral nerve) movement can be organized centrally in motor programs

Evidence for MP: Deafferentation

cutting an animals afferent nerve bundles where they enter the cord, so the central nervous system no longer can receive information from some portion of the periphery.

reaction time evidence

determined by the slowness of the stimulus identification and the response selection stage but also the movement programming

The concept of degrees of freedom addresses

different ways a component can act in a control system

Evidence for motor programs include all of the following except

eating a snow cone

The two components of the open-loop control system are

executive and effector

Two parts of open-loop control

executive and effector (no feedback/comparator)

In the open-loop control system, the comparator detects the error.

false

Open-loop control provides time for feedback and consists of slow movements.

false

The dynamical perspective theory provides evidence that motor programs exist.

false

The major difference between a motor program and a central pattern generator is that a motor program is genetically defined and a central pattern generator is learned.

false

Invariant features

features that remain the same, time after time

Characteristics of an open-loop control system include all of the following except

feedback to provide information that arises from different sensory systems

William James (1891)

general idea that many movements-especially rapid and forceful movements like kicking, typing, and throwing--seem to operate in an open loop fashion

central pattern generator

genetically defined central organization is established in the brainstem or spinal cord - serve as the basis for locomotion command neuron - stimulus from brain

storage problem

given movement is represented by a program stored in long term memory would need a unique and separate program stored in memory for every action

overall question

how and under what conditions these commands from motor programs interact with sensory information to define the overall movement pattern

Central Pattern Generator (CPG)

locomotion! when the organization is initiated by a brief triggering stimulus from teh brain, sometimes called a command neuron, it produces rhythmic, oscillated commands to the musculature as if it were defining a sequence of right-left-right-left activities

sensory neuropathy

lost much of sensory feedback - can still perform well as long as they have visual information - sensory info from limb is not critical for movement production

quick movement

motor program controls the entire action the movement carries out as though the performer were deprived of feedback central program handles movement control until feedback comes

motor program vs CPG

motor program involves learned activities that are centrally controled CPG - more genetically defined activities (locomotion, breathing)

generalized motor program (GMP)

movements can be varied along certain dimensions

Relative timing (rhythm)

no matter the direction or speed of a swing, the rhythm is the same.

movement execution

not controlled by the conscious decision making stages - motor program is the agent determining which muscles are to contract

Motor program theory fails to explain which of the following?

novel tasks and storage problems

muscle response patterns

quick movements - tripple burst pattern - agonist -> antagonist -> agonist movement programs are organized in advance and fun off unmodified sensory information for 100-120 ms - until the first reflexive activities can be involved

motor programs as open loop systems

rapid, brief, forceful movements without much conscious control - good for predictible and stable env - performer does not have time to process movement errors

motor programs and the conceptual model

roles of open-loop organization - issue commands to musculature that determine contraction - organize the degrees of freedom of the muscles and joints into a single unit - specify and initiate preliminary postural adjustments necessary to support the action - modulate reflex pathways

All of the following movements are considered open-loop controlled except

running a mile

conceptual model and olc

slow or long movement -> control is dominated by the feedback process fast 0r short movement -> open loop portions dominate

Which of the following are necessary for an open-loop controlled program to run?

specific muscles producing the action force of various muscle contraction timing and sequencing duration of contractions ~all of the above

reflex integrated into open-loop

stimulus on placing the foot -- response -> extend foot more carry more load stimulus on lifting the foot -- response -> leg flexes upward, increases the height of step

inhibiting actions

stop-signal paradigm -- action inhibition a second stop signal initiates to stop the completion of the first signal

movement flexibility

temporary reflexes - exist only in the context of performing a particular part of a particular action -> ensuring the goal is achieved even if a disturbance is encountered - ensure the intended action is generated and the environmental goal is met

Type FR (fast, fatigue resistant)

the larger motor neurons innervate the intermediate muscle fibers (Type IIa muscle fibers)

Generalized Motor Program

the most widely accepted theory-it suggests that a program exist but that movements can be varied along certain dimensions (e.g., piano can be played slower, louder, etc.)

startle RT

the prepared movement is produced normally but with an RT that may be up to 100 ms shorter could speed up by - speeding up the execuitive processing time - bypassing the executive alltogether

reflex-reversal phenomenon

the same stimuli have reversed effects when it is placed at different locations in the step cycle not traditional reflex reflex = automatic, stereotyped, unavoidable response

Type FF (Fast, fatigable)

these are the largest motor neurons and innervate the "fast" muscle fibers that utilize PCr and glycolysis for energy (Type IIx muscle fibers)

Classes of movements

throwing, kicking, swinging, etc. locomotion?-actually there are thought to be 2 separate GMPs for walking/running gait

Closed-loop controlled movements take longer than open-loop controlled movements.

true

Degrees of freedom refers to the independent components of a control system.

true

During an open-loop controlled movement, not much attention is required for the movement once the program begins to run.

true

Most movements are a combination of the dynamical perspective and motor program theory.

true

Support for motor program is evident in deafferentation research, which reveals the presumed use of motor programs without sensory feedback.

true

Support for motor programs is evident using electromyography, in which the effect of a mechanically blocked limb reveals the same pattern as unblocked limbs.

true

The generalized motor program accounts for the novel problems and storage problems associated with motor programs.

true

There is little or no time for feedback in the open-loop control system.

true

open loop control

two parts - executive and effector --- missing feedback and comparator executive passes signal to effector -- system over modifications to the action cannot be made while the action is in progress effective if things are predictible but inflexible in the face of change

Practice

used to build new, more stable, more precise, or longer operating motor programs

Anticipatory adjustments

when moving arm -> first muscles to contract are legs nad back - the movement of the arm affects posture ---- moving the arm would cause a shift in balance -> body accounts for this before the movement takes place by compensating motor program does both prep and movement at same time

practice

work to build more stable, precise, longer operating motor programs

Problems in MP Theory

Does not explain how new movements are produced in the first place (novelty problem)-separate program for every tennis shot. Lack of efficiency in this system--there would need to be a MASSIVE number of motor programs that would be required to move and perform skills. Large number of programs stored in long-term memory (storage problem)

Compare and contrast the motor program perspective and Bernstein's dynamical perspective.

Dynamical perspective is an explanation for how people control coordinated movements that emphasizes the interaction of dynamical properties of the neuromuscular system and physical properties of environmental information. Motor program perspective is an explanation for how people control coordinated movements that emphasizes the role of prestructured motor commands organized at the executive level. The dynamical perspective does not account for the invariance in the EMG patterns when the limb is blocked and during some open-loop programmed controlled movements. Support for the dynamical perspective is more apparent in ongoing continuous tasks, and support for motor programs is more obvious in brief, rapid, and discrete actions. The debate goes on between motor programs and the dynamical perspective. Mechanisms of movement are probably a combination of both perspectives (MP or dynamical system perspective), depending on three factors: 1) the nature of the action; 2) the environmental goal; and 3) the skill level of the performer.

_____________ is a device for recording the electrical activity in the muscles; it provides evidence that motor programs exist.

Electromyography (EMG)

Ways to Measure Muscle Activity

Force production (dynamometry) Strength/power assessment (1RM, peak power) Ultrasound (blood flow) Electromyography (EMG)

____________ suggests that there is a stored pattern of movement instead of a specific movement. It allows flexibility in modifying the generalized program to produce various patterns to meet the demands of the task.

Generalized motor program

Evidence for MP: Reaction Time

Henry and Rogers (1960) found that simple RT was elevated with increases in complexity of the movement to be performed.

Problems of MP Theory (continued)

How or where do humans sotre the nearly countless number of motor programs needed to for future use of storage problem? How do performers produce truly novel behavior such as performing a variant of a tennis swing that you have never performed previously? The program for such an action can be represented in an already stored motor program: the novelty problem.

Evidence for MP: Muscle Response Patterns

If the movement is blocked, a similar pattern of muscle signals are seen for the first 100 ms and more!

_____________ is a surgical procedure in which a bundle of nerves is severed and results in the prevention of nerve impulses reaching the spinal cord; it provides evidence for motor programs.

Deafferentation

____________ refers to how the sensory motor system modifies a set of prestructured movement commands to produce the action to be completed.

Degrees of freedom

_____________ refers to independent components of a control system and the number of ways each component can function.

Degrees of freedom

Three lines of evidence support the idea that motor programs exist. Define and explain each concept.

Reaction time is the interval of time that elapses from the presentation of an unanticipated stimulus to the beginning of a person's response. Reaction time increases when additional elements are added to the movement, more limbs are involved, action is more complex, reaction is longer, and more time is needed to organize the system. Deafferentation is a surgical procedure in which a bundle of nerves is severed to prevent nerve impulses from reaching the spinal cord. Deafferentation is the severing of nerves so the CNS no longer receives sensory information. Monkeys could still respond to lights and carry out learned motor programs. Motor program is presumed without sensory information or feedback. Electromyography (EMG) is a device for recording the electrical activity in the muscles. Effects from mechanically blocking a limb using EMG—activity are exactly the same as in limbs that are not blocked. There is no feedback from the moving limbs because the limbs can't move, but there seems to be a motor program that plans the movement, and the pattern on the EMG reveals the same pattern of in an unblocked limb.

Invariant features include:

Relative timing, classes of movements, parameters

Parameters

Speed of movement, force of movement, direction of movement, which limbs to use, which muscles to use

Type S (Slow)

These small motor neurons innervate the slow and high-oxidative muscle fibers (Type I muscle fibers)

This type of control system sends centrally determined, prestructured commands to the effector and runs without feedback. It is used for rapid, discrete movements.

open-loop control

Which system is used when striking a ball?

open-loop control

Which system is used while batting a baseball?

open-loop control

Which system is used while throwing a ball?

open-loop control

The major roles of motor programs include all of the following except

organize the degrees of freedom into multiple units to produce different kinds of movement

motor program

prestructured set of movements commands that defines and shapes movement

terms - styles of control

programmed action -> organized in advance, triggered as a whole, carried out without much modification central movement -> movement details are determined by the central nervous system and then sent to viruses