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HK 258 Defintions

Terms

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Kinesthesis
conscious sensation of movement
tonic vibration reflex
blindfolded patient, is asked to match position of both arms, one is shocked which causes mismatch. vibration is stretching/relaxing muscle to cause illusion of movement.
corollary discharge
Provides the sensory center with information about
the magnitude of the descending motor commands sent to the spinal cord.
INFORMATION ABOUT MOTOR COMMANDS THAT IS SENT TO
SENSORY AREAS IN BRAIN SO THAT THE BRAIN CAN DISTINGUISH SELF-INITIATED
MOVEMENT FROM ENVIRONMENTAL MOVEMENT
Joint Receptor
Perform two feedback functions during movement: regualte
the dynamic aspects of limb movement and regualte static timing or the
sequence of action. SENSORY RECEPTORS LYING INSIDE A JOINT CAPSULE
THAT PROVIDES INFORMATION ABOUT JOINT ANGLE AND JOINT ANGLE VELOCITY.
Muscle Spindle
SENSORY RECEPTOR THAT Signals the absolute length of
muscles and the rate of change of muscle length during movement.
Tonic vibration reflex: A polysynaptic reflex elicted by vibration
muscles THAT CAUSES AN ILLUSION OF MOVEMENT.
error detection mechanism
evaluation of movement correctness based upon feedback
exproprioception
INFORMATION ABOUT MOVEMENT ARISING FROM VISUAL AND
AUDITORY MODALITIES
retina
serves as the primary sensory organ of the visual system
optical nerve
transputs impulses directly to the brain
optic chiasm
the point at which the crossing, information from the right hemisphere and the left hemisphere, nerve fibers takes place
optokinetic reflex
*utilizes visual info in a manner that is complimentary to the VOR
*PRIMARY GOAL- maintain a stable vusual image on the fovea when the entire visual field moves
*longer latenecy/most respnsive at lower frequences of head movement
vestibular ocular reflex
highly adaptable reflex and has been used to study the neural mechanisms of motor learning
saccadic eye movements
helps us shift our gaze quickly between points of interest in space
smooth pursuit eye movements
used to track slow moving objects through space
focal visual system
identifies objects in the middle of the visual field; visual acuity is high
ambient visual system
detecting space around the body while providing information about where objects are located in space
primary visual cortex
where spatial organization of a visual scene is detected; most posterior portion of the occipital lobe
vergence
makes it possible to bring objects at different depths relative to the eyes into focus using binocular vision
proprioception
information about a relative position/movement of a body part
alpha motorneuron
(skeletomotor)
*assumes respnsibility of carrying the neural impulses to the appropriate muscle response synergies
*serves as the final pathway linking the CNS with the musculo-skeletal system
gamma-motoneuron
(fusimotor)
*carry its message to the msucle spindles located within the extrafusal muscles
golgi tendon organ
*signals rate of change and absolute amount of tension in a muscle
*signals muscles tension and force produced by the contraction of extrafusal muscles
joint receptors
"limit detectors" that protect the joint from injury by firing at the extremes of joint position
Ia afferent
sensory endings that detect changes in the lengths of the extrafusal muscle fibers; specifically wraps its sensory endings around both the bog and chain fibers; sensitive to muscle length and VELOCITY
extrafusal muscle fiber
part of muscle that produces force, and is attached at both ends of the muscle sheath or muscle tendon itself
intrafusal muscle fiber
shorten or elongate chain fibers to keep "fixed" distance from end of chain fibers to nuclear bag fibers
Choice Reaction Time(Test #1)
more than one stimulus with each
stimulus corresponding to a unique response
Constant Error(Test #1)
measure of response bias or averaged
signed error
Open Loop Control(Test #1)
control system that does not utilize feedback
DURING the movement's progress
Feedback(Test #1)
sensory information that arises from the act of
moving
Motor Program(Test #1)
construct responsible for control in an open
loop system --- or - pre-structured set of commands that controls
movement in the absence of feedback
Deafferentation(Test #1)
Surgical Technique severing afferent nerves
entering dorsal part of spinal cord
Relative Timing(Test #1)
ratio of duration of segment to overall
movement duration -- i.e., percentage of time a segment uses compared
to entire movement duration
Motor Equivalence(Test #1)
achieving the same goal via a different
action or movement
Degree of Freedom(Test #1)
number of dimensions or qualities that are
free to vary
Homunculus(Test #1)
little person inside of your head that controls
movement or makes sense of the world
Reaction Time
time interval between the presentation of a signal and the initiation of movement
Simple Reaction Time
movement is in response to the presentation of a single stimulus
Movement Time
represents the time interval between the start of a movement and its completion
fractioned reaction time
uses EMG to split RT into two parts: premotor time and motor time
accuracy
difference between learner's response and the criterion response
motor skill
"What" is being controlled
cognitive skill
how the processes are being organized
Behavioral Approach
manipulating variables and watching result; primarily studying outcome for duration and accuracy.
Biomechanical Approach
measuring response of movement; process of movement
Neuromuschular Approch
muscle reaction creates electicity (EMG)
Motor Control
study of movement to understand general principals of the processes underlying the development of skill
Theory
broad, far reaching explanation to account for observable data
hypothesis
specific statements about relationships between variables
Laws
doesn't fail, well- documented, but not as important as a thoery
Effectors
material that produces change
Executive
cortical control center that holds all the information necessary for action and directs lower centers within the nervous system to carry out the prescribed movement
Closed-Loop Control
the type of motor control that used afferent feedback to change movements if needed. Usually used for precise movements; novice performers with
Ballistic
stretching with movement
Reflex Chaining
the acquisition of movement patterns and motor skills as the linking of individual movements into a chain of behavior. A chain of behavior.
Limb-Blocking
type of study for the hierachical theory that used the agonist and antagonist msucles and EMG to prove the muscles must of had activation plans in advance
Generalized Motor Program
more abstract than other motor programs in structure and can be applied to a braoder range of movements
Affordance
lawful properties
Order Parameter
used to quantify the effect of a change in behavior on a dynamic system
Rate(control) Parameter
any variable that, when altered, can lead to changes in the pattern of coordination roduced by the dynamic system
Muscle Synergies
constraining muscles and joints to function in a manner that is appropriate for a desired action to solve the problem of degrees of freedom
EMG
electromyography,gives an average of voltage of muscle fibers nearby
Precision (consistency)
what variable error measures, how close a performer is to the movement he is trying to perform on every attempt
Varaible Error
represents the degree of consistency or variability associated with a performance
Perceptual Trace
feedback representation for the correct movement
Construct
Quality/process someone cannot directly observe(happiness)
Rectified EMG
measures the intensity of contraction of the muscle in voltage negative voltages are made positive(absolute value)
Intefrative EMG
interested in AREA underneath hump; find by breaking up whole shape into little shapes and adding up their area
Indirect Perception
impoverished, environment doesn't have all information, brain adds mssing information from experience/intelligence; learn how to hit a baseball using newton's laws
Direct Perception
GUIDE ACTION, directly pickup the properties of the environment (visual property) that afford certain types of action; learn how to hit a baseball by being sensitive to support info
Visual Guidance (visually guided reaching)
the role of vison in performing aiming, reaching, and grasping skills. goal-directed reaching movements requiring accuracy are adversely affected when visual feedback is removed or degraded (Woodworth's Two Phase Control)
Initial Adjustment
first stage of Woodworth's Two Phase Control; distance covering phase, transport phase, reaching, open loop
Current Control
second stage of Woodworth's Two Phase Control; homing in phase, manipulation stage,adjusting movement using visual control to acquire target, closed loop
Tau
optical variable used to predict time-to-contact
Visual Dominance
when contradictory sensory input is available, we still tend to rely on vision to guide action
Sensory Conflict
our preference for visual information can often result in slowed or even incorrect responses
Cortical Blindness
??
Saccadic Suppression
when you m ove eyes in a succad, eyes "turn off (desensitize)"
Gain
ratio of output over input; coordination of eye/head movements
Vestibular-Ocular Reflex
how the eye and head movements counteract each other to keep the gaze constant
Vertigo
illusion of motion of self while stationlary
Oscillopsia
certain objects in the visual field appear moving but are stationary
Hypokinetic
abnormal decrease in motor activity
Hyperkinetic
abnormal increase in motor control
Bradykinesia
muscular rigidity (resistance to passive displacement)
Ataxia
lack of coordination or impaired ability to execute voluntary movements
Hypotonia
reduced resistance to passive displacement of the limb
Motorneuron
made up of alpha/gamma motoneurons; neurons that activate muscle cells
Interneuron
responsible for integrating the various snesory inputs that enter the CNS at various levels of the spinal cord
Alpha Motoneuron
carries neural impulses to the appropriate muscle response synergies
Gamma Motoneuron
carries its message to intrafusal muscle fibers within muscle spindles
Motor Unit
most fundamental unit of motor control
Slow Twitch (fatigue resistant)
made of motor nuerons that have small cell bodies and axons that selectively innervate a small number of slow twitch muscle fibers (type I amount of force these units can produce in a given muscle is very small
Fast Twitch (fatigable)
made of mtor neurons that have large cell bodies and large diameter axons that innervate large numbers of a sub type of fast twitch muscle fibers (type IIB); can generate large amount of foce in the muslce very quickly
Fast Twitch (fatigue resistant)
made up of intermediate sized motor neurons with axons that innervate a second subtype of fast-twitch muscle fibers (type IIA); and are capable of generating large amounts of muscle for a longer period of time
Size Principal
reduces complexity of decison making for CNS, by dealing with actual selection of motor units by apllying irrespective of whether force is being increased or decreased within a given set of muslces
Rate Coding
the firing frequency associated with individual motor units and constitutes a second mechanism for genrating muscle force
Gamma Reflex
plays a role in the control of movements by ensuring that the muscle spindles remain ready to fire if muscle length changes unexpectedly during a movement
Central Pattern Generator
??
Ability
??
All Around Athlete
??
Genral Motor Ability
??
Mtoro Educability
??
Index of Difficulty
"log2 (2A/W)" describe how the movement times of a single performer or group of performers will be influenced as the distance bewteen two endoint targets increases and the width of those endpoint targets decreases
Fitts's Law
exlains speed-accuracy trade off
MT=a+b {log2(2A/W)}
Linear-Speed Accuracy Trade-off
As movement speed increases
spatial variability increases in a linear fashion
Effective Target Width
Variable error in movement
distance, computed in a speed accuracy trade-off task
Noise
Random variation in a
signal
Just-fast enough theory
idea that individuals choose a
duration for the initial adjustment in a speed- accuracy trade-off task, so that
current control does not need to be used very often

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