DPTD 862 - motor control & motor learning

simplest type of motor control

reflex

function of higher centers for voluntary movements

formation of motor plans according to individual’s intention & communicates with the middle level via command neurons

function of middle level for voluntary movements

converts plan received from higher centers to a number of smaller motor programs that determine necessary neural activation → broken down into subprograms that determine movement of individual joints → transmitted through descending pathways to local control level

function of local level for voluntary movements

specifies tension of particular muscles & angle/timing of joint motion needed to carry out plans sent from middle level

motor/action systems definition

systems & processes related to muscle function, including both neuromuscular & biomechanical factors

sensory/perceptual systems definition

provide information about the state of the body & features of the environment that are important for regulation of movement

perception definition

integration of sensory impressions into psychologically meaningful information

cognitive systems definition

processes that determine attention, planning, problem solving, motivation, & emotional aspects of movement

movement results from interaction of which factors

individual, task, environment

successful execution of movement requires…(steps)

• assess sensory info from environment

• select motor plan to accomplish task

• coordinate plan with CNS

• execute plan through motor neurons

• update & adjust plan via continual sensory input during task

discrete movement task

has a recognizable beginning & end

continuous movement task

the end point is not an inherit characteristic of the task

closed movement task

performed in relatively fixed or predictable environment

open movement task

requires performers to adapt to movement strategies to a constantly changing & unpredictable enviroment

regulatory environmental features

aspects of the environment that shape the movement itself (size of item you are picking up)

non-regulatory environmental factors

may or may not affect movement (noise)

PT role in motor control

manipulate domains of motor control to increase functionality of the system

constraints of motor control

• muscle weakness

• abnormal muscle tone

• coordination

• abnormal synergies

• timing

• scaling forces

• involuntary movements

• sensory impairments

• cognition/perception

cerebellum role in motor control

• receives neural signals from motor areas of the cortex, sensory info from the periphery & vestibular system for upright control & balance

• stores common movement patterns

damage to cerebellum leads to…

movement coordination deficits, NOT execution or choice of which programs to run

basal ganglia role in motor control

• selection of motor plan or behavior

• helps regulate postural tone

decreased outflow of basal ganglia leads to…

involuntary movements (chorea, hemiballismus)

increased outflow of basal ganglia leads to…

paucity of movement (PD) i.e. lack of movement/movement initiation

4 concepts of motor learning

1. learning is a process of acquiring the capability for skilled action

2. learning results from experience or practice

3. learning cannot be measured directly, more so via behavior

4. learning produces relatively permanent changes in behavior

neuroplasticity definition

brain’s ability to modify, change, & adapt both structure & function throughout life & in response to experience - occurs in ALL contexts of learning

10 principles of experience-dependent plasticity

1. use it or lose it

2. use it & improve it

3. specificity

4. repetition matters

5. intensity matters

6. time matters

7. salience matters (importance)

8. age matters

9. transference

10. interference

recovery of function vs motor learning

recovery of function: reacquisition of movement skills after injury VS motor learning: acquisition or modification of movements in normal healthy subjects

performance vs learning

performance: temporary change in motor behavior seen during practice sessions VS learning: relatively permanent change, have to retain knowledge and the apply later ((CANNOT observe within session))

implicit (non-declarative) learning

procedural, abstract knowledge without conscious awareness. reflexive, automatic, or habitual in nature - requires frequent repetition

implicit learning - non associative

learning characteristic of sensory stimuli based on repeated exposure - involves reflex pathways - habituation & sensitization

implicit learning - associative

learning to predict relationships via feedback - classical & operant conditioning

implicit learning - procedural

learning of automatic tasks through repetition

explicit learning

declarative, conscious knowledge of automatic tasks through repetition - memorization via recall & recognition

most motor learning is __ form of learning

implicit

how to set up practice for better learning, unless it is a serial task

practice the whole skill/task rather than parts of the task

how to set up practice for a novice learner

• blocked practice

• constant practice of the same task

• more guidance from therapist

• mental practice

how to set up practice for an expert learner

• random practice

• variable practice

• therapist lets patient discover

• observational (modeling)

how to provide feedback for novice learner

• knowledge of performance

• extrinsic feedback

• concurrent feedback

how to provide feedback for expert learner

• knowledge of results

• intrinsic feedback

• summary/terminal feedback

• faded feedback

more feedback leads to better performance, but it decreases…

motor learning due to reliance on outside cuing

optimal learning occurs when patient is highly…

motivated & engaged