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
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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
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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
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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
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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
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*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
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(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
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(fusimotor)
*carry its message to the msucle spindles located within the extrafusal muscles - golgi tendon organ
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*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)
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more than one stimulus with each
stimulus corresponding to a unique response - Constant Error(Test #1)
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measure of response bias or averaged
signed error - Open Loop Control(Test #1)
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control system that does not utilize feedback
DURING the movement's progress - Feedback(Test #1)
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sensory information that arises from the act of
moving - Motor Program(Test #1)
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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)
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Surgical Technique severing afferent nerves
entering dorsal part of spinal cord - Relative Timing(Test #1)
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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)
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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
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exlains speed-accuracy trade off
MT=a+b {log2(2A/W)} - Linear-Speed Accuracy Trade-off
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As movement speed increases
spatial variability increases in a linear fashion - Effective Target Width
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Variable error in movement
distance, computed in a speed accuracy trade-off task - Noise
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Random variation in a
signal - Just-fast enough theory
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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