Class Notes (810,412)
Canada (494,120)
York University (33,691)
KINE 3020 (64)
Lecture 2

KINE 3020 Week 2 Reading Notes Mosher.docx

7 Pages
Unlock Document

York University
Kinesiology & Health Science
KINE 3020
Merv Mosher

Reading 6  Degrees of Freedom Problem-coined by Nicolai Bernstein to solve how the nervous system performed well coordinated movements  Degrees of Freedom= the number of choices that a given item or situation has  Degrees of Freedom Problem: how can a complex system be constrained in a way to limit its movement? o ex. Helicopter designer creating a helicopter that makes it easy for the pilot to maneuver  As we become more practiced at a particular skill, our brains automatically solve the degrees of freedom problem Reading 7  Skilled performers have difficulty teaching beginners the skill  Fitts and Posner Three Stage Model: o Cognitive Stage:  Large, gross errors  Performance is inconsistent  Performers do not know how to fix their mistakes/ how to improve o Associative Stage/ Refining Stage:  transition into this stage after unspecified practice and improvement  Performer learns to associate certain cues with movements required to achieve the goal  Less gross error  More consistent performance  Can correct mistakes independently o Autonomous Stage:  takes years and lots of time to move to this stage  Skill is like second nature, don’t have to think about what you are doing  Can fix mistakes easily  quality of instruction and practice, as well as amount of practice is important in this stage o There is a gradual transition from one stage to another with the Fitts and Posner model  Negatively accelerated pattern is more typical of motor skill learning than others o Improvement happens quickly when initially learning a task but improvements are slow to come once practice continues and skill has been learned  Power Law of Practice: early practice characterized by improvement, but with continued practice, improvements are slow to come (Crossman 1959 study)  It takes longer for improvements to be seen with practice since the improvements made are very minute and small compared with when first learning a new skill where there is a large improvement, associated with the correction of gross error  Freezing the Degrees of Freedom= holding joints rigid when performing the skill o As improvement in the skills occurs, the frozen joints become unfrozen and are used to create smooth motions through functional synergy  We all have our own individual way of moving since we have such large movement repertoires  There is a transition that occurs from old to new movement patterns (Lee experiment) o people have to overcome movement biases o Movement biases can be overcome, but they too require time and practice o Limb movements are very unstable and irregular during a transition period, this can be frustrating for learning, extra motivation needed  EMG have shown that early in practice, person uses their muscles incorrectly when learning a new skill o more muscles than needed for the skill are involved o Timing of the muscle activation is incorrect o With Practice, the above characteristics fade away, and become more refined  Reorganization of the motor control system=the change in muscle use that occurs while a person learns a skill o is a result of the motor control systems trying to solve the degrees of freedom problem  Skilled performer can complete the same task with minimal energy expenditure, compared to a beginner who spends a lot of energy on one task  Economy of Movement=the minimization of energy during a performance task  Several energy sources o physiological energy source-measuring the amount of O2 used during a performance o mechanical energy-divide work rate by metabolic rate  Learners report a lower RPE with practice  There are certain kinematic characteristics associated with acquiring a skill o displacement:, velocity , and acceleration o Displacement is spatial, velocity and acceleration are temporal o Since spatial features are learned first, it is important to focus on this before moving to the temporal characteristics  Beginners focus on too many visual cues when learning a new skill, skilled performer know which visual cues to look for and obtain information from, thus making them more efficient o With practice, the performer learns to time their visual attention on specific cues allowing them to select and produce an action required by the situation  During experiment with skilled goalkeeper and unskilled goalkeeper, researchers noticed that skilled goalkeeper made more fixations on the kicker’s kicking foot, non kicking foot, and the ball. They knew where to look to get the information they needed, novice goalkeepers looked on all places of the kicker to get information o expert goalies had MORE FIXATIONS  When learning a new skill, there is conscious attention paid to every part of that skill. As learning progresses and improvements occur, the activity becomes more unconscious than conscious  Novice performer are unable to make corrections to movement immediately or do not know how to fix their errors; experts can.  Depending on the time constraint of the skill/movement, error corrections can be made during the movement if it is a slow movement, or they can’t be made if it is a fast movement.  The brain areas that are active during the initial stages of learning are not the same ones that are active during the later stages of learning  fMRI and PET scans are used to study brain activity during learning when a stimulus is presented  Doyon and Ungerleider proposed that brain structures most commonly associated with learning are: the striatum, cerebellum and motor cortex regions of the frontal lobe, mainly the SMA, Premotor cortex, and motor cortex. o they said that there are two loops; one involving the basal ganglia, the other involving the cerebellum  With initial learning: striatum and cerebellum activated (Cortico-cerebello- thalamocortical loop)  With later learning: basal ganglia, putamen and Globus pallidus, and inferior parietal lobe involved  The active brain areas when learning a new skill may change depending on the type of skill being learned  Learning is specific to the sources of sensory feedback available during practice o basically, if we use one sense when learning a new skill for feedback, we need that same sense in later stages of learning for feedback as we become more skilled  Expertise in a field is defined as intense practice for a minimum of ten yearsdone through deliberate practice o expertise is domain specific; you can only be an expert at one thing and one thing only o Expert know more about the activity than non experts o Experts can make decision quicker and more accurately than non experts can o Experts can look for more meaningful and useful visual cues in less time than non experts o Reading 8  The most important part of a skilled performance is deciding what to do, and to make decisions quickly and predictably.  Humans can be thought of as processors of information, input is the information that we as humans process.  We receive information through various stimuli and inputs, and generate a bunch of operations with this information to put out as output.  There are 3 stages to the decision making model: o Stimulus identification o Response selection o Response programming  The stimulus comes in and is processed in one stage and then passed on to the next stage, and that information is passed on to the third stage  stimulus identification stage (perception): o system has to decide if a stimulus is present or not o it is in sensory sta
More Less

Related notes for KINE 3020

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.