Learning Flashcards
phases of target aiming according to woodworth
identified 2 phases in the production of a target aiming task:
- > the initial impulse
- > error corrections
initial impulse of target aiming according to woodworth
the initial impulse (force and time) serves to move the limb (hand) towards the target
- > uses an open loop process of control
- > performance improves with practice
error correction phase of target aiming according to woodworth
the error correction phase guides the limb to the targe
- > uses a closed loop process of control
- > feedback (visual, proprioceptive) serves to reduce error
crossman and goodeve hypothesis of target aiming
the iterative corrections hypothesis
- > series of open-loop processes (impulses) punctuated with feedback
- > the impulse repeat (iterate) until the target is reached
relate crossman and goodeves iterative corrections hypo to time
- > they assumed that each impulse (thus correction too) takes a constant amount of time. So, movement time increases with the number of corrections required
- > more corrections are required for longer amplitudes (A) and smaller (w) targets
speed accuracy trade off (Schmidt et al. vs Fitts et. al)
rapid discrete movements to a target
- > Fitts varied amplitude and width and looked at the effects on movement time
- > schmidt varied movement time and amplitude and looked at the effects of width, referred to as effective target width
characteristics of speed-accuracy trade off (schmidt)
- > rapid discrete movements to a target
- > ballistic actions: open-loop processes
- > errors increase as movement time increases
why would a speed accuracy trade off apply to an open loop process
impulse variability
impulse: product of force and time
- > faster movements require more forces to perform the movement
- > the action is primarily depends on the force and duration of muscle contraction (i.e. neural impulses)
- > inc impulses (forces) generates increased variability so causing the movement end point to deviate further from its intended trajectory (in other words: end point variability is attributed to impulse variability)
speed accuracy trade off violations
the speed-accuracy trade off may reverse for extremely fast movement times
- > spacial accuracy tends to decrease with shorter movement times (inc. forces)
- > temporal accuracy increases with shorter movement times (inc. forces); temp acc is a function of time, not force
example of speed accuracy trade off violation
swinging hard and fast tends to produce the best performance; specifically…
- > visual information processing
- > timing accuracy
- > spatial accuracy (to an extent)
how general is a motor program according to schmit
- > the motor program won’t ever change, it is only adapted to the situation
- > i.e. you’ll use the same motor program to throw a basket ball for different distances from the net
generalized motor program (GMP) theory
- > propsed by schmidt to overcome the limitations of storage and novelty (new)
- > instead of a specific movement, the generalized motor program controls the movement patterns
- > so, GMP is used when producing a particular. type/class of movement
- > GMP are flexible so they can produce variations in the same GMP as required
characteristics of GMP
- > the GMP is a representation (of a movement pattern) in memory
- > the GMP produces a unique movement pattern when generated
- > the output of a GMP is defined by its input parameters
invariant and fundamental features of a GMP
Sequencing
- > the order of the different aspects of the movement
Timing
- > the relative timing (or phasing) of the different aspects of the movement
Forces
- > the relative forces of the different aspects of the movement
relate muscle forces to movements at varying speeds
the forces generated by any two muscles in the production of an action tends to remain proportional when movements are produced at varying speeds
i.e. movement 1
Muscle1 - 30 N
M2 - 60
movement 2
M1 - 80N
M2 - 160N
parameters/variables of the GMP that can be changed to meet the demands of the task
- > the duration/speed of the movement
- > the amplitude of the movement
- > the forces of the movement
- > the muscle(s) or limb(s) selected for the action
steps of movement production with respect to the generalized motor program
- the GMP is selected based on sensory information (from the surroundings)
- the required GMP is located and retrieved from long term memory
- the GMP is “parameterized” and the motor program is prepared for initiation
- the mvmt is performed in accord with the relatively invariant patterns/features of the GMP
- the surface features are tailored to meet the particular task demands - peripheral “sculpting” (feedback)
input:output relationship in relation to GMP
the learner must lear the relationship between input and outputs
- > the better the I:O relationship is understood, the better able the learner is to select input that is needed to produce the output
hierarchical control summary
Higher levels of control
- > the executive decision-making process; specifies the action to be produced
Lower levels of control
- > the motor programming nodes of control, including reflexes, central pattern generators, ect. possibly responsible for (some of) the details of control execution
motor learning
a relatively permanent change in behaviour as a result of practice
- > learning is inferred from changes in performance, it is not observable in and of itself
performance
- > observable
- > temporary (influenced by fatigue)
- > influenced by performance variables, may not necessarily a result of practice
learning
- > inferred from performance outcomes/changes
- > permanent
- > change (with time(
- > practice
- > influenced by performance variables (i.e. fatigue and arousal)
performance traits
- > consistency
- > flexibility
- > efficiency
- > improvement
- > degredation
performance assessment
we can measure the outcome
- > assess the outcome or end result of the motor skill being performed
relate time to performance
the amount of time it takes to complete a response is a useful measure of performance
absolute error
AE = points per trial / # of trials
ignore signs
kinematic data we observe in performance
- > displacement
- > velocity
- > acceleration
- > jerk