Psychomotor Behaviour Lab Final

Front 1

What is the difference between performance and learning?

Back 1

Performance refers to observable behaviour and it isoften unstable. The variables that affect performance temporarily, but notlearning, include motivation, arousal, and fatigue. Learning is not directlyobservable and is stable since there is a persistent change in potential forperformance. The variables that affect learning also affect performance.

Front 2

Howdoes practice influence performance?

Back 2

Performance changes are large and rapid at first andbecome systematically smaller as practice continues. However performanceplateaus when it reaches a steady state with no further change.

Front 3

How can we assess learning?

Back 3

The assessment of learning requires that temporaryperformance effects be separated from learning effects. This is done byallowing time for temporary effects to dissipate by testing learners some timeafter acquisition on a retention or transfer test. Difference in performance onthe retention/transfer test can be a better indication of learning/effects.

Front 4

How can westructure practice conditions to promote learning, as pertaining to instruction/modelling?

Back 4

Observational learning – process by whichlearners acquire capability to perform a skill by observing performance ofothers.

Front 5

How can we structure practice conditions to promote learning, as pertaining to the variability of practice schedule? (CIE)

Back 5

o Typically teachers/coaches want to teachmore than one skill in a practice.

§ Blocked practice – practice all of onetask before starting a new task – predictive and repetitious

§ Random practice – practice different tasksrandomly presented – unpredictable and non-repetitious

§ Serial practice – combination of blockedand random – predictable and non-repetitious.

§ Contextual interference effect: lowinterference (blocked) produces better acquisition performance vs. highinterference (random) produces better retention and transfer performance

· Elaborationhypothesis: CI effect occurs because in random practice, more tasks are presentin short-term memory. This allows performers to compare and contrast task withother tasks being performed – produces more distinct/elaborate memory coding.Blocked practice does not allow for this comparison.

· Actionplan hypothesis: CI effect occurs because in random practice, each task isforgotten and must be reconstructed. Reconstruction of “action plan” enhanceslearning because plan must be re-retrieved from long term memory – resulting inbetter retention and transfer performance. Blocked practice does not requirereconstruction of action plan because task remains in short term memory.

· RetroactiveInhibition hypothesis: CI effect occurs because of retroactive inhibition inblocked practice. Retention of first task practiced is retroactively inhibitedby subsequent tasks – poor retention and transfer performance relative torandom practice.

Front 6

How can we structure practice conditions to promote learning, as pertaining to feedback?

Back 6

· Feedback:sensory information that arises as a result of movement. Necessary for learningto occur. Feedback can improve, hinder or have no effect on skill learning.

o Types of feedback:

§ Intrinsic – sensory information thatarises when individuals produce a movement

· Exteroception– from sources outside the person’s body

· Proprioception– from sources within the person’s body

Extrinsic – sensory information provided by anoutside source (in addition to intrinsic – also known as augmented)

Front 7

How does cognitive effort influence motor learning?

Back 7

Themore cognitively demanding the practice is, the more one will learn duringpractice (shown higher performance on retention tests)

Front 8

What is a kinetic variable?

Back 8

Kinetics is concerned with the relationship betweenthe motion of the body and its causes. A kinetic variable characterizes forceproduced by the body.

Front 9

Describe the anatomy of a muscle.

Back 9

Muscles are made up of several muscle fibers that runparallel to the muscle and in sequence. The muscle fibers are surrounded by theendomysium. A bundle of fibers is called a fascicle, which are separated by theperimysium. The entire muscle is enclosed by the epimysium. Musclefibers are made up of sarcomeres - the functional unit of the muscle.

Front 10

How does a muscle generate force?

Back 10

Muscles generate force by contraction. This is due tothe cyclical attachment and detachment of filaments (Sliding Filament Theory).The initial length of the muscle (distance betweenthe sarcomeres) will influence the magnitude of the contraction that can begenerated.

Front 11

What factors influence force production?

Back 11

o Innervation ratio (the number of musclefibers innervated by a single motor neuron): the greater number of musclefibers innervated, the greater the force produced.

o The length of the distance between thesarcomeres.

o The type of skeletal muscle fibersinnervated (slow oxidative, fast-oxidative-glycolytic, fast-glycolytic)

Front 12

What are the different types of motor units and how are they recruited?

Back 12

There are three types of motor units: slowcontracting, fatigue resistance (S), fast contracting, fatigue resistant (FR),and fast contracting, fast to fatigue (FF). These are described by therecontraction time, half relaxation time, and peak force.

Front 13

What does innervation ratio refer to?

Back 13

The number of muscle fibers innervated bya single motor neuron.

Front 14

According to the impulse model, what is specified in the motor plan?

Back 14

The intensity of muscle activation(force) and the onset and offset of muscle activation is specified in the motorplan.

Front 15

What factors influence impulse variability?

Back 15

o Impulse variability is influenced by thevariability in force production, timing and distance.

§ Force variability – increases withincreasing force.

§ When you double the distance, the impulseis doubled; therefore the force variability is doubled.

§ When you half the movement time, the forcevariability is quadrupled, therefore the impulse is quadrupled.

§ Equations:

· Amplitude:impulse variability = k * (A)

· Movementtime: impulse variability= k * (1/MT)

· Therefore,impulse variability= k * (A/MT)

Front 16

How are impulse, temporal and force variability related?

Back 16

Impulse variability is force variabilitymultiplied by the temporal variability. Temporal variability is influenced bymovement time (faster movement time – decreased temporal variability) and forcevariability is influenced by the amplitude of movement or the movement time.

Front 17

How are feedback and feedforward control different/related?

Back 17

Monitoring sensory signals and using this informationto make movement adjustments is feedback control. While using the same sensorysources to detect imminent perturbations and initiate proactive strategiesbased on experience is feedforward control.

Front 18

Discuss examples of anticipatory motor control strategies (e.g., in postural control, catching,etc.)

Back 18

Catching a ball: before catching the ball, there is aco-activation response of the biceps and triceps. This precedes the impact bythe same amount of time no matter what height the ball is dropped from.Postural control: prior to pulling on a cable inresponse to an auditory tone, postural muscle activation is seen in the lowerlimbs, in order to provide a stable base. The brain predicts posturalconsequences of the planned movement and acts to prevent loss of balance. Theresponse is appropriate for the movement to be generated.

Front 19

How does time to contact influence performance?

Back 19

Regardless of the time to contact, the anticipatory control is initiated at the same time. Ex. Bird diving, and catching a ball. Regardless of the speed, the anticipatory control slows down the bird to the same extent prior to hitting the water and regardless of the distance, the catcher will respond when the ball is at a certain point.

Front 20

What happens if anticipatory control strategies are wrong?

Back 20

If you make predictions of how an objectwill move based on past experiences (ex. large box – make adjustments based onthe assumption that is very heavy, and ends up being very light) it mightresult in excessive adjustments or not enough. Adjustments will need to be madefrom feedback in order to correct the adjustment if the object does not move asyou intended it to.

Front 21

Are anticipatory control strategies adaptable?

Back 21

Control strategies are adaptable to themovement being made and to the stimulus. When a stimulus is present, theanticipatory control is a reaction to the stimulus, while without a stimulusthe anticipatory control is in anticipation of feedback.

Front 22

How are limb movements coordinated?

Back 22

The brain recognizes larger muscles and turns onactivation of muscles slightly earlier to accommodate for more force beingrequired.

Front 23

How does coordination change when one has to react to a stimulus versus initiate aself-paced movement?

Back 23

In the reactive task, the hand moves first,while the activation occurs simultaneously. This is because there is a shorterpath to tell the hand to move, as well the mass of the hand is less than themass of the leg. In the self-paced task, the commands are planned, organizedand scheduled according to the anticipated consequences of the action. Themovement onsets are similar, but the activation of the leg occurs before theactivation of the hand. This is because the brain anticipates the longer motorpathway and greater mass of the limb and accommodates for this by activatingthe motor units earlier.

Front 24

What is the role of sensory feedback in coordination?

Back 24

In the reactive task, sensory input is the primary control of movement. This is because sensory feedback is used to control the movement at the onset. The movement is continuously controlled bythe sensory input provided by the environment, such as the response to the stimulus. For the predictive task, since the onset of movement is produced by previous memory and experiences, which create the anticipatory response, sensory input is not relied upon for the production of the movement. However,if the movement required the participant to make adjustments, for example tothe amount of force used, then sensory input would impact performance. In the predictive mode, the body has previous knowledge as to the length of the efferent sensory pathways. Knowing that they are longer in the leg, the participant accommodates for this, resulting in a quicker response than in the hand. In the reactive mode, since this anticipatory control is not used, the body does not predict these adjustments; therefore the hand is slightly quicker than the leg to respond.

Front 25

What is postural control/equilibrium?

Back 25

The state in which all the forces acting on the body are balanced such that the body tends to stay in the desired position andorientation (static equilibrium), or in the intended movement (dynamic equilibrium).

Front 26

What is the influence of base of support on postural equilibrium?

Back 26

The larger the base support, the more stable your posture will be.

Front 27

· What are typical postural sway patterns?

Back 27

o Postural sway is typically larger in the anteroposterior direction and is present even during quiet stance.

Front 28

What are the functions of the postural system?

Back 28

1.Maintain a steady stance (balance) in the presence of gravity: balance the body over its base of support.

2.Stabilize the support portions of the body when other parts are moving: generate responsesthat anticipate movements.

3.Be adaptive.

Front 29

What is the relationship between COM, COG, COP?

Back 29

Thebody’s centre of mass refers to the point at which the mass of the body is evenly distributed; the projection of this point onto the ground is the centre of gravity, and the centre of pressure is the point of application of the force exerted on the foot from the ground. In order to remain balanced, the centre ofmass must be able to project upon a greater base of support through a largercentre of gravity, while the centre of pressure is the force acting upwards as a reaction to the force of gravity.

Front 30

How can we assess postural control?

Back 30

Measuring the directional displacement of the centre of pressure over a period of time can assess postural control. This can be done by using force platforms to measure the force applied by the body onto the ground, which is representative of the force exerted by the centre of pressure acting on the foot (feet). The displacement is measured in the anterior-posterior direction (y) andmedial-lateral direction (x), from these measurements the magnitude and direction of sway can be found.

Front 31

· How can we assess the contribution of sensory information to postural control?

Back 31

o Postural control is coordinated by multisensory information. In order to determine the contribution of thedifferent sources of sensory information, the level and reliability of theseinputs must be varied. There are three different inputs that can bemanipulated. These include vision, proprioception/somatosensory and vestibular(inner ear) senses. First, a baseline postural control would be established by testing an individual without anymanipulations. Vision is then manipulated by simply having eyes open or eyesclosed or with a blindfold. Following vision, having a constant visual image infront of the participant then controls proprioception. This would be done by attaching a box so that they do not have proprioceptive information about their surroundings. Next, somatosensoryinformation will be controlled by having the participant stand on a mat thateliminates the somatosensory information from the feet. By eliminating and isolatingthe senses, the dependence upon them can be determined by the magnitude of sway measured.

Front 32

What strategies are evoked to maintain postural control?

Back 32

There are three different strategies that can be evoked to maintain postural control. These include activation of the ankles,hips, or stepping forwards or backwards. Ankle activation, through the gastrocnemius muscles, is used primarily as the first attempt of maintaining posture. Next, the hips are activated if there is an increased requirement tostabilize the posture. Finally, if stability is lost the last response is tostep forwards or backwards to avoid falling. The muscles can also actsimultaneously, which is called muscle synergy. This incorporates ankle and hipmuscles when small displacements in posture occur, and mainly hips when the displacement is greater.

Front 33

How (and why) does postural control change with aging?

Back 33

Postural control declines with aging. This is due tochanges in the musculoskeletal system, such as reduced muscles mass (strength) and reduced range of motion. As well, changes in the sensory systems occur,such as change sin proprioceptors. Finally, psychosocial factors also contribute to decline in postural control due to depression and anxiety andliving alone.

Front 34

· How is postural control related to fear of falling?

Back 34

o Older adults with a self-reported fear of falling experience larger sway compared to older adults who do not report fearof falling. Individuals adopt characteristic postural strategies when experiencing changes in their level of fear