Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/187

Click to flip

187 Cards in this Set

  • Front
  • Back

Reaching and grasping receives input from which sensory system(s) to control this type of movement

Vision (about object and limbs) and proprioception (limb)

What must the nervous system do during hand-eye coordination

Synchronize activity of 2 systems

Is the effect of each system during hand eye coordination physically distinct?

Yes

What is the goal of the reaching and grasping movement?

*Accuracy in distance (where the object is)


*Accuracy in shape (what the object is (Size of object) and general shape)

What is the required information for accuracy in reaching?

Where (How far away is the object)

What is the required informaiton for grasping of an object

What the object is (size, shape and orientation)

Which pathway is involved for reaching?

"Where"



Dorsal stream

Which pathway is involved for grasping?

"What"



Ventral stream

If our task is to move to a target, what does the degrees of freedom (motor equivalency) theory say about how we accomplish this movement? (For reaching)

If our task is to move to a target, what does the degrees of freedom (motor equivalency) theory say about how we accomplish this movement? (For reaching)

There are an infinite amount of ways to accomplish this task and will eventually select the optimal pathway

When you are reaching what is the path of the hand almost?

It is almost always a direct line 
 
(It is the optimal solution, you are most likely to choose the shortest distance between the two)

It is almost always a direct line



(It is the optimal solution, you are most likely to choose the shortest distance between the two)

When reaching, the graph shows a smooth, bell shaped velocity of the hand. What do the peak velocity scale with?

When reaching, the graph shows a smooth, bell shaped velocity of the hand. What do the peak velocity scale with?

Movement amplitude



The peak corresponds with the time the antagonist is turned on

The further awya an object is the _____ your peak velocity

Higher

Reaching movement conssit of an ______ and subsequent _____

*Initial impulse


*Current control

What areas of the brain are likley involved in initial impulse?

Sustantia nigra


SMA


Basal ganglia


Premotor

What type of sensory informaiton is required for planning of the movement?

Visual information


To establish a plan and mainly premotor if using a visual information

What type of feedback is used in current control

Proprioception and visual

What is current control

Where make corrects to that movement based on sensory feedback

How could you determine importance of sensory systems in current control

Take it away (Remove or manipulate vision and proprioception)

What is initial impulse?

Initiation of movement

What is trajectory planning for initial impulse during initial impulse?

Internally planning the trajectory of movement (internally specifying the movement trajectory)

What sensory informaiton is important for initial impulse?

Vision of target itself (Still able to accomplish this task if have visual information of a target without information about the hand)

Is initial impulse a feedback or feedforward control?

Feedforward control



(The stimulus is generally visual information about the target)

What is the process for getting to initial impulse?

What type of informaiton do we use once the movement is initiated

Vision and proprioception

What is scientific evidence that we use visual information from the hand and target

*Distortion of visual field using the prism goggles. Have to adapt reach to distorted visual field



*Have to "learn" adapted movement pattern. Can get straight line reach after several trials which is a learned adapted pattern. Does not make correction right away because has to wait till see the hand, not till can see hand can they make the comparission with hand (saccadic movement to see object and hand then make correction)



*Once remove distortion, continue adapted movement-Will overcompensate, even though know the target is there will still move in the opposite direction

How long does it take for visual feedback to influence ongoing movement

150 ms

How do we know how long it takes for visual feedback to influence ongoing movement?

When we calculate the movements per minute and then the absolute error that someone does, as movement speed increases so does the error for eyes pen because they are still able to incorporate visual feedback.



However, during eyes closed they are consistly making the same errors no matter how fast they are doing it so 150 ms is when it doesn't matter if eyes ope nor eyes closed will stil lbe making the same errors



Any longer time than 150 ms will still ahve enough time to incorporate information to make corrections

What does visual information from a target help us with?

Trajectory planning


Initial impulse

When is current control most evident during?

When we approach target

What is the current control influence dependent upon?

Movement speed (only if longer than 150 ms)

How do we that proprioception is important for reaching

Have a distortion of limb proprioception



*Have to move the joystick to the target but there is something that moves the arms to the other side and distorts proprioceptive feedback (the joystick pulls arm towards the right) so have to make corrects they have to compensate and have "learn" adapted movement patterns



Will they remove the distorition will continue the adapted movement (overcompensate)

If the movement is longer than 80 ms can a person use proprioceptive feedback?

Yes

If the movement is shorter than 80 ms can they use proprioceptive feedback?

No, not enough time

Draw out the way to get to initial movement and then visual and proprioceptive corrections

Proprioception takes around 80 ms 


 


Vision takes around150 ms

Proprioception takes around 80 ms



Vision takes around150 ms

Can you incorporate proprioceptive or visual information faster?

Proprioceptive

What are the models that have been proposed to describe how the CNS controls accuracy of reaching movements?

1) Multiple corrections model


2) Optimized impulse model

What is the multiple corrections model

Series of corrections submovements (make corrections after each points) 

Series of corrections submovements (make corrections after each points)

What is each feedback during the multiple corrections model influenced by?

Feedback from the previous sub movement

How much does each sub movement travel duirng the multiple corrections model?

Each travels a constant proportion of the distance remaining to the target



(Keep moving a distance of 50% of the target, keep doing till get to the target)

What feedback is used during the multiple corrections model

Visual feedback movel

Distance to the center of the target = 20 cm


 


Width of the target = 5 cm


 


Each sub movement takes you 50% of the distance of the target 


 


How many sub-movements would it take to be within the target

Distance to the center of the target = 20 cm



Width of the target = 5 cm



Each sub movement takes you 50% of the distance of the target



How many sub-movements would it take to be within the target

3

Distance to the center of the target = 20 cm


 


Width of the target = 5 cm


 


Each sub movement takes you 50% of the distance of the target 


 


If the target width was smaller (but the center position remains the same), wo...

Distance to the center of the target = 20 cm



Width of the target = 5 cm



Each sub movement takes you 50% of the distance of the target



If the target width was smaller (but the center position remains the same), would the total number of sub-movements increase, decrease or stay the same?

Increase

What does the optimized impulse model state?

Initial impulse is otpimized such that the number of subsequent sub movements regarding feedback are minimized

Would the multiple corrections model or the optimized initial impulse model need more time?

Optimized initial impulse model need time for vision

Between dorsal stream and ventral stream which is involved for grasping?

Ventral

Is reaching and pointing different than grasping?

Yes

Is the reaching portion of the movement slower if the end goal is to grasp an object?

Yes



Because of speed accuracy trade off (slow down reaching speed to be more accurate)

Is the reacing portion slower if the end goal is to graps then throw an object?

Yes

Show the realtionship of movement duration with target size during pointing, grasping and grasping and throwing

What pieces of visual information are important for shaping the hand to grasp an object?

Size/shape


Orientation

During prehension (grasping) what is hand posture duirng prehension influenced by?

Severla characteristics of target object

What is grip aperature dependent upon?

Size of the object

What is grip aperature

Space between finger and thumb when hold objects

If reach for a larger object have a _____ grip aperature

Larger

During prehension (grasping) what is the orientation of the hand determined by?

The orientation of the object

How does one align their major or minor axis of an object?

Rotate the hand and wrist during approach so that grip is aligned with the axis of the object

Is there specificity in planning areas of the brain for different grips?

Yes

What is the scientific evidence that there is specificity in the planning area for the type of grip?

A monkey had the activity in its premotor cortex recorded



When the monkey had to perform a precision grip, these cells had activity



and when test with power grip such activity but activity in cells goes away a lot so showed how there were different parts of the premotor cortex dedicated to different grasps

Within the premotor cortex do different types of grasps activate specific groups of cells

Yes

Is the premotor cortex very specific for the specific type of motion

Yes



(Specifically for aperature)

Where does the premotor cortex send information to

Primary motor cortex

What is the scientific evident that there is specificity in the motor cortex?

Measured the corticio spinal neuron as well as the finger muscle EMG.



First did precision grip then power grip. Did light and heavy precision grip the corticio-spinal neuron firing did not change at all for light and heavy precision grips (meanign that force does not matter) however when between preciision grip and power grip the precision rip had more activity and the power grip had no activity

What would happen to prehension movements if a patient had damage to the dorsal stream?

Aperature wouldn't change but subject would miss the target

If the pateint had damage to the ventral stream, the patient would have trouble with what?

Interpreting object width (unable to distingusih size difference and unable to correctly interpret size of object)

Would the subject be able to accurately scale the grip aperature to the same set of objects if there is damage to the ventral stream?

Yes



Because they ahve visual feedback; able to scale larger objects larger and smalelr objects smaller

If there is a sideways T. What will the subject be able to do what can't they do?

The subject will have trouble making interpretations of the object's orientation but will be able to accurately post an object with the correct orientation 

The subject will have trouble making interpretations of the object's orientation but will be able to accurately post an object with the correct orientation

Is there a differenece in speed of movement if pointing to middle circle of A vs B? 

Is there a differenece in speed of movement if pointing to middle circle of A vs B?

Yes, one that subjects think is larger the target will be able to pointed at quicker



Therefore faster for circle A

Is there a differnece in grip aperature if reaching for the center circle in A vs B?

Is there a differnece in grip aperature if reaching for the center circle in A vs B?

No, same grip apperture because of visual feedback

What information needs to be known when picking up an object?

Weight


Surface



(These influence our force)

What are the different force applied when object is grasped

Grip force


Load force


Slip ratio


Safety margin

What is the grip force

Force between thumb and fingers

What is the laod force

Force required to lift object from table

What is the slip ratio

Determined by grip force/load force



The point at which grip force is insufficient to carry load

What is the safety margin

How high grip force/load force is above the slip ratio

For a given object does boht grip ad load force vary with object mass?

Yes

Is the rate of build up of each force constant?

Yes,



Only final magnitude changes

A higher weight = _____ load force

Higher

A heaver object needs a ____ grip force

Higher

For a given object mass with different surface materials, load force will ____ while grip force will ____

*Ramin constant


*Vary

Mroe slippery the surface, them ore or less grip force applied

More

The more slippery the surface what happens t othe rate of intiial build up in grip force

Increases

Does a higher slipperyness have a hgiher or lower safety margin

Higher because hgiher grip force

In many movement disorders do patients compensate by generating too much or too late force for a given laod?

More

More

Is the safety margin higher or lower for movement disorders?

Larger

What are the applications to health care for grip force?

Developement of prostheses


Functional robotic arms


Amazing advances

What is the process of grasping?

Need visual feedback to correct for the grip aperature  need a very specific prehension plan 

Need visual feedback to correct for the grip aperature need a very specific prehension plan

What is posture?

Position of the body or body parts

What is posture relative to?

Gravitational vertical

Can posture be static or dynamic

Can be both. Posture changes when a person moves

What is balance in terms of the center of mass and the base of support?

Maintaining the center of mass within the base of support

What is the ground reaction force

Force exerted on the body by a ground

What is the center of pressure (COP)?

The point where the resultant of all ground reaction forces acts

If put both feed on the ground where would be the sum of all of the GRF (center of pressure) be?

It would be between the both feet

What is the center of mass/gravity?

The point on an object around which the mass is equally distributed

Why do you change your COP?

To keep the COM within the base of support

What is the base of support

Region bounded by contact with the support surface

What is the stability in terms of the COM and the base of support

Maintaining the COM within the base of support

Does a smaller base of support necessarily equal a person being less stable?

No

Even when someone is standing "still" is there still some sway in the anterior-posterior and medial-lateral direction?

Yes

What are the factors contributing to balance control

*Cerebellum


*Physiological factors (breating and heart beat)


*Psychological factors


*Posture


*Muscle tone (Training and fatigue)


*Sensory feedback (Visual, vestibular and proprioception)

For quiet stance the amoutn of sway is affected by____

posture

When is there the least amount of sway for quiet sway?

When the body is aligned along line of gravity

How is quiet stance affected by muscle tone?

Muscles are tonically active during stance (especially around ankle, need to be tonically active or else will fall over)



The function to keep body aligned with gravity

Will having slack muscle increase or decrease sway

Increase (Also if too taut will have increased sway as well)



Need just enough strength



If taut can detect much more strech quickly by muscle spindles

Is visual input important for keeping postural sway?

Yes, if no postural input there is increased postural sway 

Yes, if no postural input there is increased postural sway

How does optic flow show us that vision is important for balance?

If in a box on a trolly, person would be standing in a box and when the box moves, it looks like the person is flaling foward so the people will adjust their COM (think are leaning foward so will lean backwards)



Moving lines to create illusion that person is moving foward so will shift COM backwards

How do we know that vision is involved in static postural control?

When remove vision there is greater sway as indicated by the movement of the COP and COM



After the optic flow to give the illusion that a person is swaying in one direction, he or she will move the COM in the opposite direction

What type of vestibular response is used for postural control?

Galvanic vestibular response



What type of stimulation behind the ear used to test the vestibular response in static postural control

Electrical stimulation behind the ear to activate nerve (vestibular-cochlear nerve)



Gives sensation of falling toward stimulated side

If you stimulate the right side of the vestibular system where will the subject move

To the left

During propricoception, will reduced sensory feedback form legs and feed increase postural sway?

Yes

Can COP move outside of your BOS?

No

What happens when you add in proprioceptive feedback with touch?

There is almost identical COP displacement with light and free contact of the support. It gives extra point to know where the body is even when they take away the vision. 


 


Also if they touch something there will also be an increase in ...

There is almost identical COP displacement with light and free contact of the support. It gives extra point to know where the body is even when they take away the vision.



Also if they touch something there will also be an increase in BOS but movement of COM also changes

Compared with control subjects, how would you expect damage to the cerebellum to affect COP or COM movements during static posture?

Cerebellum --> Comparator of predicted vs what actually happens through the sensory systems (make correction to balance control)



If there is damage would move around a lot, no line control of balance. Even if proprioceptors were fine, information would not be able to be interpretated



There would be greater deviations in COP and COM because causes more sway in postural control

What kind of strategies are used in response to postural perturbation

Ankle strategy



Hip strategy



Stepping strategy

For the ankle strategy what is the model?

Inverted pendulum model

For the inverted pendulum mdoel what is the bob?

For the inverted pendulum mdoel what is the bob?

The head

For the inverted pendulum model what is the fixed point?

For the inverted pendulum model what is the fixed point?

Ankle

For the ankle strategy what sequence is activated

Distal to proximal

For the ankle strategy during forward sway what muscles activated

Active muscles on back of body from distal to proximal sequence (EMG activities)



Gastrocnemius --> Hamstrings ---> Erector spinae

For the ankle strategy during backward sway what is activated

Muscles on the front of the body from distal to proximal sequence



Tibialis anterior ---> Quads --> Abs

When is the hip strategy used?

If too big for ankle strategy

For the hip strategy during forward sway what muscles are activated

Activate muscles on the front of the body then the bakc of the body from the proximal to distal sequence



(Activate muscles on the front of the body first (abdominals --> quads --> Tibialis anterior) then activate muscles on the back (Erector spinae --> hamstrings --> Gastrocnemius) from proximal to distal for both times

During the hip strategy during the backward sway?

Activate muscles on back of body then front of the body proxima to distal sequence for both

What is a last resort to prevent fall when other strategies fail

Stepping strategy

What is the stepping strategy?

Move BOS to catch up with the COM

When there is normal and has a pretty large BOS which strategies are used?

When there is a narrow beam what type of postural control strategies are used?

When there is a normal condition what postural control strategy is primarily used?

Ankle strategy

When there is a narrow beam (restricted BOS) what postural control strategy is used?

Primarily use hip strategy

Why do we raise our arms when balance is compromised?

To control COM (and easier to move arms than the hips)



Also to catch self when fall so acts as protection (key reason)

For anticipatory control which muscles are activated

postural muscles before primary movers

Is anticipatory control a feedforward or feedback ocntrol?

Feedforward

What happens to muscle activation patterns if the body is supported during anticipatory control?

Don't activate postural control muscles, just activate primary movers

What is the pathway of anticipatory control?

How does healthy and parkinson's disease patients differ in postural control?

*Switch from ankle to hip strategy when standing on narrow beam



*Parkinsons' disease (doesn't have correct muscle tone, don't use sensory feedbak becaus emuscle tone)


-Complex pattern


-Unable to adapt postural strategies to different contexts

What is postural control with cerebellar damage?

Patients with cerebellar damage have problems scaling response amplitudes



Response is too large and too long, so they overshoot and must activate antagonists



(IE lean forward, lean back way too much, so have to activate front as well)

Does postural sway increase or decrease with aging

Increase particularly in fallers

What is aging associated with

*Reduced muscle strength


*reduced sensory function (vision, vestibular, peripheral)

With greater muscle activity is there slower or faster response to perturbations?

Slower

How do you improve balance control in older adults with history of falls?

Vibratory insoles (additionally sensory feedback to enhance the feedback)



with "noise" sway is reduced



Older adults, diabetic neuropathy, stroke patients



Obstacle course (Combines cognitive and physical functions)

Since older people operate closer to the limits of base of support what does that mean for balance control?

Have bad balance control

What kind of proprioceptive response do older people have and what does that do to to postural sway

Have a decreased proprioceptive response and increased sway

How do you help with the proprioceptive response for older people

Give them more proprioceptive feedback with vibrating insoles to excite the skin receptors at the bottom of their feet



Helps to improve postural control with the increased proprioceptive information

What is a training to help older adult's increase postural control

Put older individuals navigating thorugh an obstacle course of real life items (contains both cognitivee (reading newspaper) with motor movements) so acts as a dual tasking

What is locomotion?

Rhythemic alternating of limbs on opposing sides of the body for the purpose of progression

Locomotion is a series of what?

Balance perturbations

Does locomotion have sensory contributions?

Yes

What is one stride cycle?

From heel strike - heel strike

What percent of the stride cycle is the swing phase?

40%

When the swing phase start?

Starts at toe-off

When does the swing phase end?

Ends at heel strike

What percent of the stride cycle?

60%

When does the stance phase start?

Starts at heel strike

When does the stance phase end?

End at toe off

How much of the stride cycle is the double support?

10%

What is double support?

Both feet on ground

What is the heel strike used?

Absorb shock so head is not bouncing around with every step n

What is the mid-stance used for?

Transfer center of pressure (Move COP through foot and toe off allows for propulsion forward)

What is the toe off for?

Propulsion

What is the equation for gait speed?

Gait length * Stride frequency

How could you increase speed?

Increase stride length


Increase stride frequency

To increase speed by increasing stride length and stride frequency which one is increased first?

Will be a combo of the two but does depend.


If you are walking up a hill and have to increase speed will you increase stride frequency or stride length?

Frequency

If you are walking down a hill and have to increase speed will you increase stride frequency or stride length?

Stride length

How do we select gait speed?

Look for the one with a decreased metabolic cost of walking 


 


When map out the graph of different walking speeds at different levels see a parabala shaped and when choose speed will be walking at the speed with the lowest cost of transp...

Look for the one with a decreased metabolic cost of walking



When map out the graph of different walking speeds at different levels see a parabala shaped and when choose speed will be walking at the speed with the lowest cost of transport



As increase the terrain the energetic sot increases but still walks at the minimal cost of transport speed



This is part of the learning process

What is the key compoenent to accurate processing of visual information/

Head stability

What does head stability do for the visual system

Allows visual system to pick up visual flow information more clearly

Do people with damage to vestibular system have problems with gait stability?

Yes

When stepping to the right would the right side or the left feet be in stance phase? Which would be in swing phase?

Right foot is n stance phase


Left foot is in swing phase

If take a step to the right which way is the head moving

Right

When step is to right, head is moving to right and the eyes will be moving to _____

Left

Is the eye movement in synch with leg movement?

Yes

What happens when the cerebellum is damaged

Coordination breaks down and movement patterns suffer 


 


The movement is not as smooth as the control and have saccades in middle (made for correction) because eye movement help to make corrections isnce vestibular information is off


...

Coordination breaks down and movement patterns suffer



The movement is not as smooth as the control and have saccades in middle (made for correction) because eye movement help to make corrections isnce vestibular information is off



Not able to get vestibular feedback to keep head stable so constnat corrections to keep gaze fixated

Where is gaze generally focused?

In the direction of movement

What kind of fixations do you have on an obstacel?

Brief, intermittent fixations

Do you look at an obstacle when cross it?

No W

Why can you complete an obstacle course with eyes closed?

Had visual information to begin with and did it once and so can form a subconcious (procedural) memory of the movement and motor behavior

If something is in the procedural memory, can you get to it slower or faster?

Quicker

What is procedural memory?

Working memory of task-specific visuo-spatial informaiton "the mind's eye"

Is visual information about optic flow is important to gait velocity?

Yes

As locomotion speed increase does visual flow speed increase or decrease?

Increase

How do they test optic flow on gait speed?

Have subject walking on treadmill with a dome to change how optic flow shown either increase or decrease. If increase optic flow speed gait speed decreases. The brain trusts visual information more and thinks is more accurate and ffel that the body movement is incorrect so want to slow down visual information and slow down gait speed

When optic flow is faster than expect, gait speed _____

Decreases

When optic flow is slower than expected, gait speed ____

Increases

What are other factors affecting gait?

Change posture IE high heels

What postural control factors affected by wearing high heels

High heels change activation of muscles



And make it more difficult to keep self aligned with gravity and need to make lots of hcanges for body



Change activation of muscle especially in back etc