PTP712 Neuroscience in Physical Therapy Winter 2018Motorlearning and the recovery of functionEmiliaBartramUniversityof Michigan – FlintActivity#1: Compare and contrast the explicit and implicitlearning processes.Tom’sinability to recall the sequence from day to day shows he hasdifficulties with explicitlearning.
This may be because he hasmedial temporal lobe lesions which do not allow the formation ofexplicit memory.1However, withcontinued practice, the skill mayenter his implicit memoryeven though he is unable to explicitly remember the stages ofmovement. This can occur in patients with lesions of the temporallobe and the hippocampus, where new explicit information could not belearned, but skill learning isunaffected.2 Procedurallearning, a type ofimplicit memory, creates amovement schema that can then be applied to different contexts. Ifprocedural learning is notpossible despite repeatedpractice, Tom will not be safe as he has not committed the movementschema to memory. Thus,he cannot then translate this to other conditions, so he will beunsafe to walk with two canes innew environments.
Activity#2: Compareand contrast various motor learning theories.Fittsand Posner’s 3 stage model assumes three stages of learning; thecognitive, the associative, and the autonomous stage. Jean is likelyto manage the high cognitiveand attention demands of relearning a task. Based on the video, itappears that Jean is stillin the cognitive stage of reaching for a glass. This is shown in herinability to fully form a palmer grasp, showing she still needs todevelop a motor program for this skill, herjerky movements, and her inability to isolate muscle movements (usingher trunk to abduct the shoulder).
Observing the video, she also appears to require a high level ofconcentration to complete this task, andrelies heavily on her declarative memory as she manipulates theinformation consciously.3Therefore,Jean requires external sources of information such as the PhysicalTherapist to help produce a correct movement pattern.4As her movement improves, she will require less external informationand begin to be able to adapt to the environment – different sizeand weights of the object she is reaching for.
It is thereforeimportant that the therapist initially provides feedback to helpdevelop the correct movement pattern, and then allows Jean to applythis to different settings.3Duringthe autonomous phase, feedback should be precise, andJeanshould be allowed to make errors as this has shown improvedperformance during novel tasks.5However,this model does assume that the movement will be able to be learned.In Jean’s case, she has other limitations to movement such asweakness, spasticity, and flexor synergy. These must be addressedbefore she can achieve the associative and autonomous stage, as hermovements are likely to stay effortful if, for example, she hasspasticity limiting elbow extension. She may however gaincompensatory strategies, and therefore while a specific movement iseffortful and variable in performance, the functional task becomesproficient.
For example, she may learn to use her left hand to aidher right in creating a palmer grip, and with practice, this couldbecome a proficient movement the requires little energy or attentionto complete. Activity#3: Compare and contrast various motor learning theories.Freezingthe degrees of freedom involves constraining the joint movement usingco-contraction. The release of the degrees of freedom allows improvedefficiency of movement and greater ability to adapt the movement forthe environmental demands. Forexample, initially the degrees of freedom in the lower limb may beconstrained to flexion and extension of the hip and knee to re-learnbasic stepping after hemi-paresis, with little ankle movement.
Thetherapist may need a ‘hands-on’ approach to help constrain themovement, for example to prevent circumduction. As this becomeseasier, you could introduce stepping around objects, that wouldencourage the use of abduction and adduction in the hip, andinversion/eversion of the ankle which would require the release ofmore degrees of freedom to allow for adaptation to the environment.This would allow synergies to develop, allowing more flexibility ofbody movements.3 Fromthis, you could take your patient outdoors where there is unevenflooring, obstacles, and busy pavements, to release more degrees offreedom. This assist the development of adaptation to differentcontexts, leading to efficient movements and the ability to exploitthe limb movements to navigate the changing environment.
References: Shumway-Cook A, Woollacott MH. Motor Control: Translating Research into Clinical Practice. 5th ed. Philadelphia: Wolters Kluwer Health/Lippincott Williams & Wilkins; 2017 Milner, B. Amnesia following operation on temporal lobes, In: Whitty CWM, Zangwill OL, eds.
Amnesia. London, UK: Butterworths, 1966: 109-133 Edwards, W.H.
, Motor Learning and Control: From Theory to Practice. Belmont, CA: Cengage Learning, 2010 Fitts PM, Posner MI. Human Performance. Belmont, Calif: Brooks/Cole Pub.
Co; 1967. ) Poole JL. Application of motor learning principles in occupational therapy. The American journal of occupational therapy. : official publication of the American Occupational Therapy Association. 1991;45:531-537