Quiz Compare and contrast declarative (explicit) vs. procedure (implicit or non-declarative) memory. Address the following: What is learned? Give examples.

Presentation on theme: "Quiz Compare and contrast declarative (explicit) vs. procedure (implicit or non-declarative) memory. Address the following: What is learned? Give examples."— Presentation transcript:

1 Quiz Compare and contrast declarative (explicit) vs. procedure (implicit or non-declarative) memory. Address the following: What is learned? Give examples. What brain areas are involved in the formation of memory? Where is the memory stored?

2 Reading Assignments Shumway-Cook: 21-39 Min H. Huang, PT, PhD, NCS
PTP 512 Neuroscience in Physical Therapy Motor Learning: Theories and Practical Applications Reading Assignments Shumway-Cook: 21-39 Min H. Huang, PT, PhD, NCS

3 Outline for today’s lecture
Define motor learning and learning Procedural learning Declarative and associated learning Adam’s theory Schmidt’s theory Ecological theory Motor learning occurs in stages Measuring learning outcomes Transfer of learning Feedback and giving augmented feedback Practice conditions

4 Defining motor learning

5 Motor Learning Motor learning is the understanding of acquisition and/or modification of movement. As applied to patients, motor learning involves the reacquisition of previously learned movement skills that are lost due to pathology or sensory, motor, or cognitive impairments. This process is often referred to as recovery of function.

6 PT Implications How can I best structure practice (therapy) sessions?
How often should my patient practice? Will the motor skill learned in one context transfer to another? Will my patient be able to walk safely at home/community after therapy? Should I simply the task? Should my patient practice weight shifting in the // bars vs. walking in the gym (part vs. whole practice)?

7 Learning vs. Motor Learning
Learning is a relatively permanent change in behavior due to practice, or the process of acquiring knowledge about the world. Motor learning: a set of processes associated with practice leading to a relatively permanent change in the capacity for skilled actions.

8 Concepts of Motor Learning
Learning is a process of acquiring the capacity for skilled action Learning results from experience or practice Learning cannot be measured or observed directly; it is inferred from behavior Learning produces relatively permanent changes in behavior; short term change is not learning)

9 Motor Performance  Motor Learning
Motor Performance is the temporary change in motor behavior seen during a practice session e. g. A patient learns how to shift more body weight over the weaker leg at the end of the therapy session. However, the patient still bears more weight on the unaffected leg at the next visit to PT. Learning has not occurred.

10 Motor Performance  Motor Learning
Performance may be influenced by many other variables, e.g. fatigue, level of learning/skills, anxiety, motivation, cues or manual guidance given to the learner Motor Learning is a relatively permanent change in motor behaviors that are measured after a retention period and only result from practice.

11 Forms of motor learning

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13 Nondeclarative (Implicit) Learning: Non-Associative Learning
A single stimulus is given repeatedly and the nervous system learns about the characteristics of the stimulus Habituation ↓ response to the stimulus, e.g. exercises to treat dizziness in patients Sensitization ↑ response to the stimulus, e.g. training to enhance awareness of loss of balance Occurs when a single stimulus is given repeatedly and the nervous system learns about the characteristics of the stimulus. Habituation is a decrease in responsiveness that occurs as a result of repeated exposure to a non-painful stimulus. Sensitization: An enhanced response to many different stimuli after experiencing an intense or noxious one. For example, an animal responds more vigorously to a tone of lesser intensity once a painfully loud tone has been played. Here we say that the animal is sensitized.

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15 Nondeclarative (Implicit) Learning: Associative Learning
Classical Conditioning learn to predict relationships between two stimuli e.g. before learning: verbal cues + manual guidance  stand up; after learning: verbal cue  stand up patients are more likely to learn if the associations are relevant and meaningful Explore the world to identify the relationships between one’s body and the environment is a critical task for patients with movement problems. Associating a weak, ineffective (unconditioned-U) stimulus with a strong, effective (conditioned-C) stimulus to produce a desired response (R) e.g. Verbal cues (U) coupled with manual guidance (C) to help a patient make the movement (R) Patients are more likely to learn if the associations are relevant and meaningful to them

16 Nondeclarative (Implicit) Learning: Associative Learning
Operant Conditioning learn to associate a certain response, from among many that we have, with a consequence; trial and error learning e.g. relearn stability limits after ankle sprain; verbal praise from PT behaviors that are beneficial and rewarded tend to be repeated Predict one’s behavior with the consequence Therapists use positive feedback(“Good job!”) to reinforce the successful accomplishment of a task Neural circuits involved in operant conditioning Cerebellum for movements Amygdala for emotions Premotor areas for associating sensory events with a specific movement (“Mirror Neurons”)

17 Procedural Learning Does NOT require attention, awareness, or other higher cognitive processes One automatically learns the rules for moving, i.e. movement schema Learning requires repeating a movement continuously under a variety of situations Patients with damage to cortex (e.g. TBI, dementia, aphasia) can still  performance e.g. some of the rules for performing a sit to stand Shifting the weight over to a new base of support Produce extensor force in the hips and legs against the body weight Learning under a variety of contexts enables the successful performance of action in variable environments. A patient who had a TBI and cannot verbalize the sequence of use of an assistive gait device may still be able to learn the movement sequence. Neural structure involved cerebellum striatum of the basal ganglia

18 Declarative (Explicit) Learning
Require attention, awareness, and reflection Results in knowledge or facts (e.g. objects, places, events) that can be consciously recalled and expressed in declarative sentences, e.g. “1st I move to the edge of chair. 2nd I lean forward and stand up”; instruction from PT; mental rehearsal; motor imagery With declarative learning, motor tasks can be practiced in a different way, e.g. athlet mental rehearsal before the competition Neural circuits involved in declarative learning Sensory association cortices Medial temporal lobe Hippocampus

19 Declarative (Explicit) Learning
Practice can transform declarative into procedural or nondeclarative knowledge e.g. a patient first learns to stand up may verbally repeat the instruction; after repeated practice, the patient may be able to stand up without instruction Processes of declarative learning: encoding  consolidation storage retrieval Encoding requires attention: encoding is affected by motivation and attention to the information, and ability to associate it with stored memory. Consolidation convert the memory into long term memory. It involves structural changes of neurons. Storage involves the retention of long term memory. Retrieval is the recall of information and different long term storage. It is subject to distortion since an individual reconstructs the memories from a combination of different sites. Retrieval is most accurate when the context is similar or the same to the context it is created. Declarative memory is stored in the cortex (likely in temporal cortex), not hippocampus!

20 Think-Pair-Share When helping a patient to relearn motor skills, should the PT emphasize non- declarative (implicit) or declarative explicit) learning? Depends on location and type of CNS lesion. Temperal lobe involved in declarative learning. Cerebellum involved in procedural learning.

21 Theories of motor learning

22 Adams Closed-Loop Theory
In motor learning, sensory feedback from the ongoing movements is compared with the stored memory of the intended movement Memory trace selects and initiates a movement Perceptual trace, built-up over practice, is the internal reference of correctness

23 Adams Closed-Loop Theory
Clinical Implications Accuracy of a movement is proportional to the strength of the perceptual trace Patient must practice the movement repeatedly to ↑ the perceptual trace Limitations Cannot explain open loop movement or novel movements

24 Schmidt Schema Theory Emphasizes open-loop control processes and generalized motor program “Schema” is a generalized set of rules for producing movements that can be applied to a variety of contexts Equivalent to motor programming theory of motor control

25 Schmidt Schema Theory Information stored in short-term memory after a movement is produced Initial movement conditions, e.g. body position, weight of an object, step height Parameters of a generalized motor program Outcome of the movement, in terms of knowledge of results Intrinsic sensory feedback of the movement

26 Schmidt Schema Theory Information stored in short-term memory is converted into two schemas Recall schema selects a specific response and contains rules for producing a movement Recognition schema evaluates the response correctness and informs the learner about the errors of a movement Recall schema ~similar to Adams memory trace Recognition schema ~similar to Adams perceptual trace

27 Schmidt Schema Theory Clinical Implications
Variability of practice↑ learning and generalized motor program rules Novel movement can be made accurately based on previously learned rules Limitations Vague; no consistent research finding in support of variable practice Cannot account for one-trial learning (In the absence of a schema)

28 Ecological Theory Learning involves the exploration the perceptual and motor workspace Identify critical perceptual variables, i.e. regulatory cues Explore the optimal or most efficient movements for the task Incorporate the relevant perceptual cues and optimal movement strategies for a specific task

29 Ecological Theory Clinical Implications
Patients learn to identify relevant perceptual cues that are important for developing appropriate motor responses, e.g. identify relevant perceptual cues for reaching and lifting a heavy glass: weight, size, or surface of the glass vs. its color?

30 Fitts and Posner Three Stage Model: Cognitive stage
Learner activities Learn what to do Learn about the task and goals Require high degree of attention Select among alternative strategies Performance may be more variable Fast improvement in performance Develop a motor program

31 Fitts and Posner Three Stage Model: Associative Stage
Learner activities Refine the skills Refine a particular movement strategy Performance is less variable and more consistent Cognitive monitoring decreases Improve the organization of the motor program

32 Fitts and Posner Three Stage Model: Autonomous Stage
Learner activities Become proficient, save energy Attention demands are greatly reduced Movements and sensory analysis begin to become automatic Able to perform multiple tasks, scan the environment Ability to detect own errors improves

33 Implications for PT Motor learning probably occurs in stages
Activities of the patient are different in the different stages Activities of the therapist should be different in the different stages

34 Systems Three-Stage Model
Learners initially restrict degrees of freedom (DOF) and gradually release the DOF as the task is learned and the skills improve Novice Stage Simplify movement by constraining joints and ↓DOF, e.g. muscles co-contraction Less energy efficient

35 Systems Three-Stage Model
Advanced Stage Gradual release of additional DOF More adaptive to different contexts Expert Stage All DOF released Efficient and coordinated movements Exploit the mechanical and inertial properties of the limbs and the environment

36 Gentile’s Two Stage Model
Early stage Understand the task goals, develop movement strategies, recognize regulatory features of the environment Late stage Refine the movement, consistent and efficient performance Closed skills become fixation/consistent Opened skills become diversification/ adaptive

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38 Think-Pair-Share A patient is learning to use a walker. What would the patient be able to do at each stage of learning? Cognitive stage (early)- Association stage (late)- Automatic stage (late)-

39 Application of motor learning theories

40 How to Measure Learning?
To separate the relatively permanent effects of learning from the transient effect of practice, learning can be measured using retention or transfer designs. Test the subject after a retention interval, typically >= 24 hr Choose the same task (retention test) or a variation of the task (transfer test)(e.g. different speed or lighting conditions for walking)

41 Practice Level: How Much? PRACTICE, PRACTICE, PRACTICE
Animal Studies 9,600 retrievals over 4 week period (Nudo, 1996) 7,000 trials of food catching in 5 weeks (Pavlides, 1993) Humans? Dose-response log-linear relationship Are patients getting enough practice?

42 Feedback (FB) FB is all the sensory information that is available as a results of a movement Types by mode of delivery Intrinsic (e.g. proprioception) Extrinsic (e.g. instruction from PT) Types of FB by information provided Knowledge of results (KR) Knowledge of performance (KP)

43 Knowledge of Performance (KP)
Information about the movement patterns Usually intrinsic but can also be extrinsic Proprioception, Biofeedback, video recording, verbal instruction (e.g. “Your elbow was too low.”) Note that Shumway-Cook’s borrowed from Schmidt’s book on this section but she might have missed the point? It was not clear from what she stated in the book. I looked up Schmidt’s original text and this is what he stated. Schmidt and Lee, Motor Control and Learning, 4th edition. Human Kinetics.

44 Knowledge of Results (KR)
Information about the result or outcome of the movement in terms of the goal Verbal instruction (e.g. “You were off the target.”), proprioception (e.g. feeling loss of balance during a fall) Note that Shumway-Cook’s borrowed from Schmidt’s book on this section but she might have missed the point? It was not clear from what she stated in the book. I looked up Schmidt’s original text and this is what he stated. Schmidt and Lee, Motor Control and Learning, 4th edition. Human Kinetics.

45 Characteristics of Good Feedback
Timing Allow some time to reflect between trials Summary FB Summary FB after a few trials works better than after every trial Give more frequent summary feedback (e.g. after every 5 trials) for complex tasks than for simple tasks

46 Characteristics of Good Feedback
Accuracy Positively reinforce correct performance Augmented (extrinsic) Feedback Video/visual of movement patterns alone does not help; need to provide error- correcting cues as well AVOID VERBAL BOMBARDMENT Can be given concurrently or afterwards

47 Characteristics of Good Feedback
Frequency and Fading Schedule More impaired patients may require more frequent FB. Avoid giving FB every trial. Decrease the amount of FB given across learning stages so the patients won’t become dependent on FB. Study of 4 TBI patients with memory deficits (Haring, 2002) 2 patients who received feedback on 75% of movement attempts were more successful in learning a 7-step supine  stand transfer task than 2 patients who received feedback on 25% of movement attempts

48 Practice Conditions Massed vs. Distributed Practice Schedule
Distributed in early stage (e.g. 20 min X 3 days) to avoid fatigue and massed in later stage (e.g. 60 min in one day) Constant vs. Variable Practice Usually variable practice (walk at different speeds) results in better learning outcomes than constant practice (walk at the same speed) in health adults

49 Practice Conditions Random vs. Blocked Practice
Contextual Interference: practice that makes the performance more difficulty initially may result in more effective learning in the long term Random practice (practice multiple tasks in 15 min) results in better learning than blocked practice (practice one task in 15 min) in healthy adults but not necessarily patients Blocked Practice Practice all of one movement at one time and then practice all of another movement Better for performance, but less efficient for learning Random Practice Continuously change the task being practiced Better for learning Forces learner to reconstruct motor program with each movement (active learning process)

50 Practice Conditions Whole- vs. Part-Task Practice
Task specificity says the best practice is the task itself If utilizing a part technique, the part (e.g. hip and knee flexion, extension) must be a naturally occurring component of the whole (e.g. walking) Movements requiring “whole” practice Cyclic movements, e.g. gait Multi-joint movements where timing of movement components is linked, e.g. reaching for a cup to pick up Okay to practice “parts” if: Task is easily broken down into parts Muscle strengthening is desired outcome – be sure to link strengthening type exercise to ultimate task being learning (task specificity) Practicing dorsiflexion while in sitting and expecting carry-over into gait does not work. Gait depends on central pattern generators and many postural synergies where muscles are activated together. Picking up a cup involves the transport task of the arm and the grasp task of the hand. The timing of the grasp is such that the hand will open to prepare to grasp the cup before it reaches the cup

51 Practice Conditions Transfer
Amount of transfer is determined by the similarity between the two tasks or the two environments The more closely the practice environment resemble those in the performance environment, the better the transfer Guided vs. Discovery Practice

52 Practice Conditions Mental Practice
The same neural circuits producing the movement are also active during mental practice Can produce large positive effects on performance of the task (Rawlings 1972) Physical + mental practice produces the best learning outcome Thinking about how a movement is done can facilitate learning Cognitively try out different strategies for achieving a motor task, e.g. floor  WC transfers SMA is active when doing mental practice of sequence movements

53 Practice Conditions Action Observation
Reorganization of the primarily motor cortex in patients with stroke after observation of the desired action + motor training, but not observation of irrelevant movement + motor training Implications for patients with poor motor ability Mirror neuron system: Inferior parietal lobule (IPL), Ventral premotor cortex (PMv), inferior frontal gyrus (IFG). Garrison KA, Winstein CJ, Aziz-Zadeh L. The Mirror Neuron System: A Neural Substrate for Methods in Stroke Rehabilitation. Neurorehabilitation and Neural Repair. June 1, ;24(5): Mirror neurons found in the premotor and parietal cortex respond not only during action execution, but also during observation of actions being performed by others. Thus, the motor system may be activated without overt movement. Rehabilitation of motor function after stroke is often challenging due to severity of impairment and poor to absent voluntary movement ability. Methods in stroke rehabilitation based on the mirror neuron system—action observation, motor imagery, and imitation—take advantage of this opportunity to rebuild motor function despite impairments, as an alternative or complement to physical therapy. Garrison, 2010