Motor control exam 1
what is the function of the primary motor cortex regarding motor control?
'intentions' produce output to spinal cord that yield motor outcomes
what is the function of the primary motor cortex?
contains programming necessary for volitional movements
what are the different types of validity?
content, face, construct, concurrent
what is the purpose of gamma motorneurons?
contribute to maintaining tension of spindle
what is agnosia?
deficit in ability to identify what you are looking at?
what is ideamotor apraxia?
deficits in ability to plan or complete motor actions that rely on semantic memory
ankle strategy: distal to proximal muscle activation or proximal or distal?
distal to proximal
what is the basal ganglia?
large nuclear masses deep within and at the base of cerebral hemispheres and in the midbrain
what are the zones of the cerebellum?
medial, intermediate, lateral
where is the GTO located?
ms tendon junction
what are synergies?
muscle linkages; fixed patterns of activation, hierarchically controlled; adaptive and dynamic
what detects absolute ms length and changes is ms length?
muscle spindles
what maintains muscle stiffness?
muscle spindles
what deficit occurs with injury to the substantia nigra?
muscle tremors, rigidity
what is paraplegia?
muscle weakness affects lower extremities
what are the receptors of the somatosensory feedback system?
muscle: spindle, GTO joint cutaneous: mechano, thermo, niciceptors
what response types are autogenic?
myotatic reflexes, long-loop reflexes
what are the three types of neurological reflexes?
myotatic, long-loop, triggered
where are the greatest number of muscle spindles?
neck, extraocular ms, hand
what lobe contains lobules VI-X?
posterior
what is static stability affected by?
postural alignment, muscle tone, postural muscle tone
hip strategies: distal to proximal muscle activation or proximal or distal?
proximal to distal
specific muscle responses occur distal or proximal or proximal to distal?
proximal to distal
what is the difference between signs and symptoms?
signs - objective symptoms - subjective
when learning a new task, what sensory system is more heavily weighted?
visual
what are components of normal postural control?
MSK, internal representations, adaptive mechanisms, anticipatory mechanisms, sensory strategies, individual sensory systems, neuromuscular synergies
what is impaired individuation?
abnormal coupling between related muscles
what are the clinical implications of motor prohgramming theory?
abnormal movement (including problems in CPGs or higher level motor programs); re-learn correct rules for an action; ;re-train movement important to the task, not just muscle re-ed in isolation
what are some motor control deficits?
abnormal muscle tone, loss of selective muscle activation and abnormal synergies, coactivation
what is hypertonicity?
abnormal muscle tone; either rigidity or spasticity
what is hypertonia?
abnormally high muscle tone
what is hypotonia?
abnormally low muscl etone
what are fixed base of support strategies in perturbed stance?
ankle and hip strategies
what lobe contains lobules I-V?
anterior
what are the different lobes of the cerebellum?
anterior, posterior, flocculonodular
what is effector anticipation?
anticipate how long the movement will take (ex, time bat swing)
what is prediction regarding the physiology of feedforward systems?
anticipation contribute to being better able to predict
what are APAs?
anticipatory postural adjustments
what motor development is the brainstem responsible for according to hierarchical theory?
apedal function
what is a base of support?
area of the body in contact with support surface center fo
where does the caudate receive input from?
association cortex (sensory)
when does the putamen experience minimal activity?
at rest
when are gamma motor neurons activated during voluntary ms contraciton?
at same time as muscles
what may be some dysfunctions of the cerebellum if impaired?
ataxia, action or intention tremor (rhythmic, involuntary oscillatory movement), dysdiadochokinesia, vestibulo-ocular dysfunction, ataxic dysarthia, hypotonia
what may cerebellar function look like?
ataxia, discoordination of voluntary movement, dysmetria, action or intention premon, dysdiadochokinesia, vestibulo-ocular dysfunction, ataxic dysarthria, hypotonia
what sense is processed faster, visual or auditory?
auditory about 20ms faster than visual
what may tasks be classified by regarding different types of motor control?
body action, organization, UE manipulation, motor --> cognitive focus, inter-trial variability, environmental predictability
where does the cerebellum send output to?
brainstem (medial and lateral descending systems); vestibular nuclei; motor, premotor, and prefrontal cortices
what is the center of pressure?
center of the distribution of total force applied to the supporting surface
what measuring outcome methods are used to measure movement physiology and records electrical activity of ms and picks up electrical potentials?
EMG
how does the visual feedback system work?
light is focused by the cornea and lens --> travels to retina
what is the major weakness of the reflex theory and its clinical applications
limited view of movement, reflex testing for diagnosis and treatment
what is the major weakness of the systems theory and what are the clinical implications?
little attribution of perceived environment; biomechanics, errors allowed
what is apraxia?
loss of the ability to execute or carry out learned purposeful movements
what does intensity mean when referring to a stimulus?
loudness/brightness (greater intensity = faster processing)
what did reflex theory identify?
-interaction of excitatory and inhibitory processes (reciprocal innervation - activation of flexors can lead to deactivation extensors) -sensory receptors: nociceptors, muscle spindles
what are the clinical implication of reflex theory?
-use sensory input to control motor output ; stimulate good reflexes and inhibit primitive reflexes; heavy reliance on feedback
what are the three functional regions of the cerebellum?
1) spinocerebellum (vermis and intermediate hemispheres) 2) vestibulocerebellum 3) cerebrocerebellum (lateral hemispheres)
reaction time loop time
120-180 ms
adaptational abilities do not occur until ______
15 months
what sensory fiber dies off in large sensory fiber neuropathy?
1a - no proprioceptive input
what types of muscle fiber types do monosynaptic stretch reflex loop excite?
1a afferent
what muscle spindle fibers are in the GTO? other neruons?
1b afferent, GABA interneruon
myotatic reflex loop time
30-50 ms
when does a compensatory step occur compared to a reaction-time volitional step?
50-100msec sooner
long-loop loop time
50-80 ms
when do equilibrium reactions develop?
6 months - 4 years
what CNS peripheral input is the most sensitive to balance distrubance?
80-100ms
triggered reaction loop time
80-120 ms
reflexive movement was thought to only be seen after ______ according to hierarchal theory
CNS damage
what is degrees of freedom problem?
CNS may be able to reduce/freeze degrees of freedom to simplify motor control strategies; may be achieved by CNS grouping control over individual muscle into sub-units
GABA or Glutamate: GPe to subthalamic nucleus?
GABA
GABA or Glutamate: GPi to thalamus?
GABA
GABA or Glutamate: striatum to GPe?
GABA
GABA or Glutamate: striatum to globus pallidus?
GABA
GABA or Glutamate: striatum to substantia nigra?
GABA
what are the limitations of reflex theory?
Lashley, Taub, other refuted theory; goal directed movement is possible without somatic sensation (surgical) even if vision is occluded
what is parkinson's disease?
Movement disorder caused by the death of dopamine neurons in the substantia nigra-pars compacta
does correlation indicate causation?
NO
what is Hick's law?
RT increases by about 150ms for each doubling of SR choice/pairing
What are central pattern generators?
Spinal circuits that give rise to rhythmic motor activity
what is sensitivity?
a test detecting dysfunction when it is present
what is specificity?
a test detecting no dysfunciton when it is not present
what is individuation?
ability to selectively activate a muscle allowing isolated joint motion
what is activation of a muscle determined by?
activation of synergies and its weighting within those systems
what is the function of the cerebellum?
adjust motor responses, modulates force and range of movements, involved in motor learning
what is thew response-programmign stage?
after selecting response, we must covert it to a coordinated action
what is head righting?
aligns the eyes with horizon and the head with the trunk
what is the function of the neurological reflexes?
allow fast corrective responses
where are the motor correspondents of the cortical homunculus located and where does it receive input from?
along precentral gyrus of frontal lobe; handles signal from premotor area of frontal lobes
where are the sensory correspondents and where do they receive input from?
along the postcentral gyrus of the parietal lobe
what is the difference in gamma motor neurons and alpha motor neurons during voluntary contraction?
alpha --> activate extrafusal fibers gamma --> activate intrafusal ms fibers
what is a motor unit?
alpha motor neuron + fibers it innervates
what affects strategy selection?
amplitude/velocity of destabilizing forces, perceived LOS, perceived ability to recover, fear of falling
what is stability?
balance - ability to control center of mass in relationship to the base of support
what cerebellar function is the vestibulocerebellum responsible for?
balance and eye movement
what does "underlying muscle tone" mean?
balance between agonist and antagonist
when do humans develop anticipatory postural control?
begin showing activation prior to reaching in sitting (in the neck) at 4-5 months; trunk activated at 9 months, standing and inconsistent arm movemnts 10-11 months, gastrocs at 13 months, adaptational at 15 months?
what is constant error?
bias/accuracy - consider the target ( motor behavior)
what motor development is the cortex responsible for according to hierarchical theory?
bipedal function
what are rods responsible for?
black and white/night vision
what are the motor symptoms associated with PD?
cardinal motor symptoms, resting tremor, bradykinesia, rigidity, postural instability, gait disturbance
what are the components of the basal ganglia?
caudate nucleus, putamen, globus pallidus
what is the premise of motor programming theory?
central motor pattern can be elicited either with sensory stimulation or through central processes
what does reaction time involve?
central planning (premotor) and muscle activation (motor)
what is stiffness?
change in tension/ change in length
what are characteristics of a stimulus that may impact identification/processing?
clarity, stimulus, modality
what individual constraints need to be considered when understanding motor control and postural control?
cognition, attention, perception, arousal, sensory integrity, flexibility, muscle performance, muscle tone, movement patters/motor function
what is feedback control?
command specifies desired state
what is feedforward control?
command specifies response
a target on the right requiring a right hand response would be stimulus response ______
compatible
what are cognitive aspects of behavior?
connects "higher function" to motor control
what is variable error?
consistency; measurement of consistency of performer, relative to their average performance
If someone could not intersecting shapes on a paper, they would have _____
constructional apraxia
what is the function of the caudate?
controls conscious contractions of certain skeletal muscles; process info and new tasks/circuits; modulate multiple sensory inputs from association cortex?
what is the function of the supplementary motor cortex regarding motor control?
coordination of complex learned responses (throwing, typing); coordination of large muscles for posture
What is optic ataxia?
correctly identifies object, does not know what to do with it
what neuroanatomical structures are included in the hierarchical theory?
cortex, midbrain, brainstem spinal cord
in the optic chiasm, axons from the nasal retina of each eye ______; axons from the temporal retina of each eye ______
cross over; do not cross
what are cones responsible for?
daylight/color vision
in a negative relationship, if one variable increases, the other ____
decreases
what determines what motor strategies do we use to response to a threat to balance?
depends on characteristics of perturbation (direction and magnitude), biomechanical constraints, environmental conditions
what are attractor wells?
depict levels of variability; deep well = preferred pattern, shallow = easier to change, less stable
what is the significance of the CPGs?
despite motor deficits from higher order areas, rhythmic motor actions may be able to still be performed by activating these CPGs which do not require input from higher control areas; continued training required
what is receptor anticipation?
detect upcoming event using sense (ex ball poitched)
what is motor unit size related to?
dexterity and power
what is the major weakness of the program theory and its clinical implications?
did not describe biomechanics; motor learning, practice scheduled, feedback
what is the location of the subthalamus?
diencephalon
what is the location of the thalamus?
diencephalon
what about the task needs to be considered when understanding motor control and postural control?
different tasks require different types of motor control
what is the major weakness of the ecological theory and its clinical implications?
difficult to study in lab context; individual exploration environment
what is apraxia of speech?
difficulty planning and coordinating the movements necessary for speech
Direct or indirect circuit: GPi to thalamus (VA/VL)?
direct
Direct or indirect circuit: cortex to striatum?
direct
Direct or indirect circuit: striatum to globus pallidus
direct
what are the different categorizations of task organization when classifying tasks?
discrete, continuous, serial
what is meant when a task is classified by task organizaiton?
does movement have a recognizable beginning and end
what are the limitations of the hierarchical theory?
does not explain why adults have reflexive behavior in certain situations; result of bottom up control
what is the construct validity?
does the instrument accurately measure a construct (abstract variable)
what is concurrent validity?
does the instrument agree with other instruments? use gold standard
What is face validity?
does the instrument appear to measure what it sets out to measure at face value
what is content validity?
does the instrument measure all dimensions of a particular function?
what neurotransmitter does the substantia nigra send to the striatum?
dopamine
what are the pathways coming from the primary visual cortex?
dorsal and ventral pathway/stream
optic ataxia is a result of a problem with the ____ stream
dorsal stream (posterior parietal lobe)
what theory incorporates environment, one's perception?
ecological
what is the ecological theory?
effects of environment on motor control and how its shapes out actions
Are gamma motor neurons afferent or efferent?
efferent
what are gamma motor neurons?
efferent to intrafusal ms; maintain tension; SC sends efferent info from ventral horn to spindle; tiny axons to contractile elements but not strong enough to generate movement
what is motor performace?
efficient control of motor processes, the execution of a movement (skill)
what are open skills?
environment is constantly changing
what are closed skills?
environment is somewhat constant/controlled; next movement is predictable; movement variability decreases with practice
are equilibrium or righting reactions more mature response?
equilibrium
what reactions are responsible for postural reflex development in the cortex?
equilibrium reactions
what are some ways to measure motor performance outcomes?
error (accuracy), time and speed, movement magnitude, performance
what is motor behavior?
every kind of movement from involuntary twitches to goal-directed actions, in every part of the body from head to toe, in every physical and social context from solitary play to group interactions
what is the result of activation of a direct pathway?
excitatory effect on thalamocortical projections and therefore movement/behavior production
dopamine activation has an overall ______ effect on thalamocortical projections by _____ the direct path and _____ the indirect path
excitatory; excites; inhibits
what are anticipatory adjustment influenced by?
expectations, anticipation, practice
when do joint receptors fire?
extreme ends of range
what are the clinical limitations of motor programming theory?
fails to account for influence of MSK and environment for motor control (gravitational forces)
is the putamen concerned with new tasks or with familiar circuits?
familiar circuits
what are the different nuclei of the cerebellum that contribute to motor control?
fastigial, interposed, dentate
what is compensatory feedback in anticipatory postural control?
feedback - postural muscle activated again after primary movers ti further stabilize body
what is the preparatory phase of anticipatory postural control?
feedforward - postural muscle activated >50msec in advance of prime movers to compensate for destabilizing effects
where are there high concentrations of cutaneous receptors?
fingers
when do protective reactions emerge and in what order do they develop?
first to the front, then to side, backwards in prone, quadruped, sitting, then standing
what strategies are included in reactive postural control?
fixed support strategies, change in support strategies
what are characteristics of a closed task?
fixed, habitual patterns, minimal variation, lower demand on. information processing systems
what are characteristics of synergies?
flexible, task dependent
what is the long-loop reflex aka?
functional stretch reflex
what is temporal anticipaiton?
giving a constant "foreperiod" can reduce reaction time; foreperiods that are 2-3 sec reduce reaction time better than those that are 12 sec
do postural reactions respond more to global stimuli or primitive reflexes?
global stimuli
GABA or Glutamate: cortex to striatum?
glutamate
GABA or Glutamate: subthalamic nucleus to GPi?
glutamate
what is descending movement response organizaiton?
head-hip-ankle; head movements are opposite to hip and ankle
what deficit occurs with injury to the subthalamus?
hemiballismus
what theory explains distributed control on multiple levels and incorporates neuraxis complexity?
hierarchical
how is the motor system organized?
hierarchically
what does high vs low variable error mean?
high - inconsistent performance low - scores very similar, little variation
what does high vs low constant error mean?
high - less accurate low - acurate
in non-constrained conditions is there higher or lower stepping frequency?
higher
voluntary movement is initiated by ____ levels according to heirarchial theory
higher
what medial-lateral strategies are used to primarily recover stability?
hip and joint; minimal ankle and knee
what is the difference between hypokinetic and hyperkinetic disorders?
hypo: PD; diminished movement hyper: HD; excessive movement
if someone were to put their shoes on before their socks, what would they have?
ideational/conceptual apraxia
what is the function of the primary visual cortex? why is this important for motor control?
identifications of colors, lines, edges, depth, etc; location and object identification
if someone were to not know how to use a toothbrush, what would they have?
ideomotor apraxia
what is the clinical application of anticipation?
improve processing time for patients; strategize constant foreperiod and decrease stimulus response pairing
what is ideational/conceptual apraxia?
inability to conceptualize a task and impaired ability to complete multistep stress; inability to select and carry out an appropriate response
what is constructional apraxia?
inability to draw, construct or copy simple configurations such as intersecting shapes
what would be a deficit as a result of primary motor cortex injury?
inability to perform purposeful movement even though no paralysis may exist
a target on the right requiring a left hand response would be stimulus response ______
incompatible
what occurs if there is too much variability according to the dynamic systems theory?
inconsistent performance, often due to disease
what is response selection sports strategy?
increase opponents SR pairings --> increase uncertainty --> delay response
the index of difficulty _____ by ___ unit for each _____ of amplitude and _____ of width
increase, 1, doubling, halving
in a positive relationship, if one variable increases, the other _____
increases
response time _____ with more complex movements
increases
what are components of fitts law?
index of difficulty, speed-accuracy tradeoff, beginning of the field of human factors (ergonomics)
Direct or indirect circuit: GPe to subthalamic nucleus?
indirect
Direct or indirect circuit: striatum to GPe?
indirect
Direct or indirect circuit: striatum to substantia nigra?
indirect
Direct or indirect circuit: substantia nigra to striatum?
indirect
postural control and motor control emerges from the interactions of the _____, _____, and _____ constraints
individual, task, environment
what is the result of activation of an indirect pathway?
inhibitory effect on thalamocortical projections and therefore a suppression of movement/behavior
what is movement time?
initiation of a response to the end of the movement
what is the function of the posterior parietal cortex regarding motor control?
integrates body position and location of external objects; output goes to prefrontal cortex
what is the difference between inter and intra rater reliability?
inter - do different people rate the same? intra =- how consistent in the same person
what is the function of fast fatigue muscle spindles
intermediate, somewhere fatiguable, twice the force production
what is perceptual anticipation?
internal rhythm (ex cadence with running)
what is the function of the subthalamus?
involved in ballistic movements
what is the function of the putamen?
involved in movement control
what determines UE manipulation when classifying tasks?
is UE interaction with an object present or absent?
what determines environmental predictability in addition to open/closed?
is the movement self-paced or externally paced - stair climbing, escalator, walking down hallwall
when does the putamen experience increased synaptic activity?
just prior to movement
what is the function of fast fatiguable muscle spindles?
large force burst needed (jump)
when is hip strategy used?
larger, faster pertubation, support surface compliant or smaller than feet
what zone of the cerebellum contains the anterior and posterior lobes as well as the flocculus?
lateral
what are the systems that go to the spinal cord contributing to the motor system?
lateral and medial motor systems
what makes up the cerebrocerebellum?
lateral hemispheres
primary medio-lateral motion is ____ ______ movement
lateral pelvic
what new directions did reflex theory expose?
learned non-use, neuroplasticity, constraint induced movement therapy
what is the clinical application of fitts law?
make a task more or less challenging for a patient by analyzing task requirements; tasks that require low demands or high demands for accuracy
what is fitts law?
mathematical model of human movement relative to environmental interaction; time to complete a targeted movement depends on the distance to the target and the width of the target; predicts that the time taken to get to the target is a function of the ratio between the distance to the target and width of the target
what are postural reactions?
maturational motor skulls that develop during the first year of life, and form the basis for attainment of functional motor skulls
what do equilibrium actions consist of?
mature responses to regain balance, include counter-rotation of the head and trunk away from the direction of displacement and use of the extremities
what zone of the cerebellum contains the vermis and nodulus?
medial
what is the location of the substantia nigra?
midbrain
do neurologically-intact individuals use one strategy or a mixture to control AP sway?
mixture
am r of 0.5/-0.5 indicates ____
moderately strong relationship
what is a generalized motor program?
modificable spatial-temporal rules for discrete skills
what are myotatic reflexes?
monosynaptic stretch reflex - spindles, gamma loop, same muscles
stepping strategy is more or less complex than stable BOS stratgies?
more complex
what is the premise of ecological theory?
motor control evolved so we can cope with environment, accomplish goal-directed movement
what causes apraxia?
motor disorder caused by damage to posterior parietal cortex or corpus callosum; TBI, neurodegenerative illness, congenital
what is stasticity?
motor disorder; velocity-dependent increase in tonic stretch reflexes with exaggerated tendon jerks
what concepts were introduced with the motor programming theory?
motor equivalence (new idea) and degrees of freedom reframed
what cerebellar function is the spinocerebellum responsible for?
motor execution
what is the function of the cerebellum regarding motor control?
motor learning; fine correction of speed and distance of ongoing movements
what cerebellar function is the cerebrocerebullum responsible for?
motor planning
what are postural movement strategies also known as?
motor strategies
what is the definition of paresis?
motor weakness - inability or difficulty in recruiting and/or modulating skeletal motor units to generate torque or movement
what is the putamen primarily concerned with?
movement
what is body righting?
movement around the body axis to assume anti-gravity positions
what is the basal ganglia involved in?
movement control (esp higher level and internally generated), learning (reward-based), cognition, memory, affect
what is motor skill?
movement result of learning, producing a planned movement with certainty and maximum efficiency
what is the premise of dynamic systems theory?
movements were active and goal-oriented; not conditioned reflexes; concepts still held: motor equivalence, degrees of freedom problem via linkages of muscles; novel idea: CNS is solely responsible for movement 'need to understand characteristics of the system you are moving", internal/external forces acting on the body
what are the clinical implications of the dynamic systems theory?
need to understand physical properties of the body, properties used to facilitate movement, variability
what is variability?
needed for flexible/adaptive motor control
what would be a deficit as a result of injury to the putamen?
negative basal ganglia sx
what would be a deficit as a result of injury to the caudate?
negative basal ganglia: akinesia (hesitation), bradykinesia, abnormal postural adjustments
what are the pattern generators for gait?
nervous system
what are the two uses of the term motor program?
neural connections that are hard-wired or stereotyped or higher level/hierarchically organized programs that store rules for producing movement
what can cause normal postural reactions to be absent or severely impaired?
neurological pathology/injury
when is coactivation present?
neurologically intact individuals just learning a skill and individuals with neurologic pathology
does the GTO have descending infleunces?
no
what does it mean if a test has 100% sensitivity?
no false negatives
what does it mean if a test has 100% specificity?
no false positives
can myotatic reflexes be modified by instructions? are they affected by the number of choices?
no, no
what does the flocculonodular lobe contain?
nodulus flocculus
what is muscle tone?
normal passive resistance to stretch
what is the major weakness of the hierarchical theory and what are its clinical implication
not all 'low level' behahviors are immature; neurodevelopment treatment
what is a problem with feedforward systems?
not always accurate, prediction error (illusions)
what is an advantage of feedforward systems?
not relying on sensory feedback which takes extra time
what are some factors that may increase response time?
number of moving parts, accuracy of movement, movement duration
what is criteria for a measurement?
objective, reliable, valid
what is the function of the premotor cortex regarding motor control? what neurons exist here?
organizes sequences of movements; location of some mirror neurons
what is a nonlinear system?
output of this self-organization is not proportional to its input
what is the function of the prefrontal cortex regarding motor control?
overall planning of movements; species goal of movement, not details
what types of mechanoreceptors?
pacinian corpuscles - stimulated by deep pressure merkel's disks, ruffini endings, meissner corpuscles - stimulated by light touch
upper motor neuron syndrome primary symptoms?
paresis and abnormal muscle tone (spasticity)
where is the dorsal stream and what question does it process?
parietal lobe; where is it, what do I do with it
what is the function of the thalamus (VL/VA)?
part of the motor planning; communicating w/ basal ganglia
what does the firing pattern depend on?
passive vs active; direction of motion of joint
what are the tracts that allow for the cerebellum to receive/send information?
peduncles
what is the function of the somatosensory feedback system?
perception of sensory stimuli from skin and internal organs
what terms did reflex theory coin?
perception, synapse
the ecological therapy places a large emphases on ______
perception/action relationship
what occurs during response selection?
person has information from environment and perception of what is happening in the environment; now must select response
what receptors are used in visual feedback?
photoreceptors: rods and cones
what are the limitations of the dynamic systems theory?
places less importance on role of CNS in motor control, increased emphasis on body mechanics and mathematical concepts describing motor control
what is the center of mass?
point at the center of total body mass
what is the vestibulocerebellum?
portion of the cerebellum that sends output to the vestibular nuclei for balance and eye movements
what do kinematic measurement devices measure?
position, velocity, acceleration, angle
what would be a deficit as a result of injury to the globus pallidus?
positive basal ganglia - hypertonicity, tremors (rhythmic), chorea (jerky), athetosis (slow), ballismus (flinging) and tics
what is orientation?
posture - ability to maintain an appropriate relationship between the body and segments between the body and environment for a task
what is the visual feedback system important for?
posture, balance, locomotion, accuracy, dexterity, manipulation
what affects the timing of anticipatory postural adjustments?
practice
where does output from the putamen go?
pre-motor and supplementary motor
what are the phases of anticipatory postural control?
preparatory and compensatory
what is stimulus identification?
presentation of environmental stimulus, uses memory (association to prior information), stimulus, pattern recognition
what are primary and secondary effects regarding classification of impairments with CNS lesions?
primary impairments affecting motor, sensory/perceptual, and/or cognitive/behavioral systems from lesion directly but as a result of the original problem
what are structures involved with motor planning?
primary motor cortex, caudate, putamen, globus pallidus, subthalamus, substantia nigra, thalamus
what part of the brain contains the homunculus?
primary somatosensory cortex
what reactions are responsible for postural reflex development in the brainstem spinal cord?
primitive reflex
what is the core of the dynamic systems theory?
principles of self-organization, variablility
what theory defined core questions and concepts with empirical suport?
program theory
what dictates the number of muscle spindles?
proportional to the mass of the muscle and those requiring precise control
what are the 4 pieces of information stored in memory when making a movement?
proprioception, force and speed, feeling of movement/how movement looked, outcome
what motor development is the midbrain responsible for according to hierarchical theory?
quadrupedal function
what are the different types of pattern recognition?
random vs context-specific; static vs dynamic
what is saccadic eye movements?
rapid eye movement for foveal vision (reading, tennis match viewing)
what is the significance of postural reactions?
reactions automatically provide for maintaining the body in an upright position through changes of muscle tone, in response to the position of the body and its parts
what are equilibrium reactions?
reactions providing balance when the center of gravity is disturbed
what is response time?
readctive time + movement time
what is anticipation regarding physiology of feedforward systems?
ready the system to reduce response selection stage
what are the two schemas information is abstracted into in motor programming theory?
recall schema (motor) - initial conditions/specific situations and intentions; recognition schema (sensory) - detector of error/success
is foreperiod is random, temporal anticipation is ______
reduced
what theory states reflexes may be the basis of movements and has the fastest responses?
reflex theory
what was the premise of reflex theory?
reflexes are basis for all movement; complex movement is a result of chained reflexes; sensory input is necessary for movement
what was the main claim of motor programming theories?
refuted idea that movements were conditioned reflexes; theorized movement are active and goal orientated
what is the function of the globus pallidus?
regulates the muscle tone necessary for specific intentional movements?
what are environmental constraints on movement and postural control?
regulatory features (weight, size, shape of object; type of walking service); non-regulatory features (affect performance - background noise, distractions
what is the motor homunculus?
related to number of alpha motor neurons to innervate ms of the body by region
what are protective reactions?
required to prevent injury id the equilibrium reactions are unable to restore balance
what stage of motor processing deals with hick's law?
response-selection
what is the function of the substantia nigra?
responsible for balance between dopinergic inhibition and cholinergic excitation of the straital output (GABA)
what is the treatment for PD?
restore dopamine level (L-dopa), balance overactive BG circuit (DBS)
what reactions are responsible for postural reflex development in the midbrain?
righting reactions
what are the different types of postural reactions?
righting reactions, equilibrium reactions, protective reactions
what is motor equivalence? what theory is it a part of?
same motor command can lead to very different movements (same goal); motor programming
what side of the body is affected with a cerebellar lesion - same side as lesion or contralateral?
same side
when preparing for movement, what does the brain need to do?
select appropriate behavior, specify direction and amplitude
what is the function of the GTO?
senses tension and inhibit homonymous ms/excites antagonist; fatigue muscle protection
where does the putamen receive input from?
sensory areas and motor/premotor areas of cortex
according to the hierarchal theory, what is needed to control movement?
sensory feedback
what does clarity mean when referring to a stimulus?
sharpness (sharper = faster processing)
what are the three types of tasks to analyze response time?
simple RT task, choice RT task, go/no go discrimination RT task
what is coactivation?
simultaneous activation of additional muscles during functional movements
what are the classes of muscle spindles?
slow fatigue, fast fatigue, fast fatiguable
when is ankle strategy used?
small perturbation, firm support surface
what is the function of slow fatigue muscle spindles?
small sustained ms contractions for posture
what peripheral input is favored under fixed surface conditions in adults?
somatosensory
what are types of hypertonia?
spasticity and rigidity
what is the difference between spasticity and rigidity?
spasticity velocity dependent, rigidity not
what are the two types of anticipation regarding the physiology of feedforward systems?
spatial and temproal
what is the function of the brainstem in regard to motor control?
species-specific behaviors; origin of motor neurons to spinal cord
what conditions require anticipatory adjustments?
speed, weight of load to be moved, support
where does the cerebellum receive info from?
spinal cord and cerebral cortex
what role do muscle spindles play in muscle stiffness?
spindle helps to mediate normal stiffness/ms tone for control of posture and movement during action and rest
what are long-loop reflexes?
spindles, SC interneurons, cortex or cerebellum, same muscles
what structures are involved in long-loop reflexes?
spindles, cortex/cerebellum, same muscles
what structures are involved in myotatic reflexes?
spindles, gamma loop, same muscles
what is meant when a task is classified by body action?
stability <--> mobility tasks -determined by support of base still or moving
what is a correlation coefficient?
statistical measures that expresses the amount of shared association that exists between the two data sets; ranges +1 to -1
what are the components of normal postural control?
steady state, anticipatory, reactive, and adaptive postural control
what are change in support strategies for perturbed stance?
stepping strategy - chem COOM is moved outside BOS
describe the path of visual information?
stimulus that appears to your left will be projected onto the nasal retinal of the L eye and temporal retina of your R eye
what are the stages of information processing?
stimulus-identification, response-selection, response-programming
monosynaptic stretch reflex loop is activated when?
stretch ms; activation of agonist; reciprocal inhibition
An r of 0.9/-0.9 indicates ____
strong relationship
what are righting reactions?
support positioning of the head vertically in space, alignment of head and trunk, and alignment of trunk and limbs; head and body
what theory incorporates biomechanics, self-organization, variability, and synergies?
systems theory
where is the caudate located?
telencephalon
where is the globus pallidus located?
telencephalon
where is the putamen located?
telencephalon
where is the ventral stream, what question does it process?
temporal lobe; what is this
what are the clinical implications of hierarchical theory?
test reflexes, prevent primitive reflexes; moralize ms tone and reduce hyperactive stretch; facilitate normal patterns of movement
what does the sensory organization test do?
tests somatosemory, visual, and vestibular reliance - manipulation with blindfold and foam surface
where does the basal ganglia send output to?
thalamus, brainstem
what is anticipatory postural control (aka proactive)?
the ability to activate muscles in legs and trunk for balance in of advance of potentially destabilizing voluntary movements; the preselection or tuning of sensory-motor system sfor upcoming events
what is steady state postural control?
the ability to control center of mass relative to base of support in predictable conditions
what is adaptive postural control?
the ability to modify sensory and motor systems in response to changing tasks and environmental demands; maintain postural control while moving through space; ability to counteract destabilizing external forces to avoid a potential fall while simultaneously executing a complex task
what is the definition of motor control?
the ability to regulate or direct mechanisms essential to movement
what is reactive postural control?
the ability/organization of movement strategies to recover a stable position following an unexpected perturbation;
what is stimulus-response compatibility?
the degree of association (naturalness) between a stimulus and response
what is postural control?
the process of the CNS controlling the body's position in space for purposes of orientation and stability
what is the central set?
the state of the nervous system that is influence or determine by the context of the task; enavle CNS to potimize postural responses under new task conditions
what is reaction time?
time from the beginning of a stimulus to the beginning of a response
what is the subtractive method proved key example?
time it takes to performa a task depends on the number and types of mental stages involved
what occurs if there is too little variability according to the dynamic systems theory?
too little - non-generalizable, injury prone
what is the premise of hierarchal theory?
top-down organization of motor control
what is the cortical humunclus?
topographic representation of the body parts; motor and motor correspondents
what is the function of the primary somatosensory cortex regarding motor control?
touch input from entire body (homunculus); some output to prefrontal and spinal cord
what response types are not autogenic?
triggered reactions, reaction time
true or false: anticipatory postural adjustments involve activation and adjustment scaling the amplitude of the adjustments
true
what muscle spindle types are sensory afferent from ms spindles?
type 1a and type II
what are the functions of the cerebellum?
unconscious processing of sensory input, motor control (timing, muscle patterns, learning), equilibrium/balance/postural control, muscle tone via brain stem and spinal cord circuits
what are motor functions associated with subcortical pathology specifically regarding the cerebllum?
unconscious processing of sensory input; motor control (timing, muscle patterns, learning); equilibrium, balance, postural control; muscle tone via brain stem and spinal cord circuits
what is spatial anticipation?
using spacial cues to predict/reduce reaction time (ex - soccer goalie using kickers foot placement to predict where ball will go
what are characteristics of an open task?
variability and flexibility, changing environment, greater difficulty to plan movement, increase demand on information processing systems
what structures are involved in reaction time?
various receptors, higher centers, any musculature
what are triggered reactions?
various receptors, higher centers, associated musculature
what structures are involved in triggered reactions?
various receptors, higher centers, associated musculature
agnosia is a result of a problem with the ______ stream
ventral
what makes up the spinocerebellum?
vermis and intermediate hemispheres
what is the center of gravity?
vertical projection of center of mass
what are forms of sensory feedback?
vision, touch, pain, temperature, smell, taste, proprioception/kinesthesia, interoception, vestibular
what peripheral inputs does the CNS use to organize info?
visual, somatosemsory, vestibular
what is tetraplegia?
weakness affecting all four limbs
what is hemiplegia?
weakness affecting one side of the body
what is the principle of self-organization?
when a system of individual parts comes together, its elements behave collectively in an ordered way
what are significant aspects of the motor programming theory?
when making a movement, 4 pieces of info is stored in memory; information is abstracted into 2 schemas; schemas stored as generalized motor program
stance widths ___ than ____ result in minimal ankle motion
wider than 8cm
what is objectivity?
will two different observers get the same result when evaluating the same thing?
where are joint receptors found?
within joint capsule
what are type II afferent fibers located and most sensitive to?
wrap around less elastic region of spindles nuclear chain; most sensitive to static ms length
what are type 1a afferent fibers located and sensitive to?
wrap around most elastic part of spindles nuclear bag; most sensitive to dynamic ms stretch
can generalized motor programs be applied to new skills?
yes
is a certain amount of movement variability normal? does this level need to be determines?
yes and yes
does stepping or reaching occur even when the COM is within BOS?
yes trend for higher stepping frequencies in non-constrained conditions; neurologically intact individuals appear to use mixture of strategies in controlling AP sway
can neurological reflexes be sterotyped?
yes, also modified or inhibited
is it possible to reduce RT with training?
yes, experts can reduce their RT for high dimension SR down to the RT of a single choice
can long-loop reflexes be modified by instructions? affected by number of choices?
yes, no
can reaction time be modified by instruction? affected by number of choices?
yes, yes
can triggered reactions be modified by instruction? affected by number of choices?
yes, yes
when to motor symptoms appear in PD?
~80% of neurons degenerated
