Motor Systems

Question 1

regions important for motor system

Answer 1

SMA, primary motor cortex, ACC, basal ganglia, cerebellum, inferior frontal cortex, frontal eye field, premotor cortex, primary sensory cortex, parietal cortex

Question 2

difference in function between cortical and subcortical system

Answer 2

cortical –> voluntary selection, planning and guidance of goal directed movements, also learning movement sequences

subcortical –> involuntary/automatic movements, modulation of movement, learning and optimization

Question 3

function and organization of lateral tract

Answer 3

fine motor control (arms, legs, figners)

fully crosses in medulla to other side of body—> where we get contralateral control

Question 4

function and organization of medial tract

Answer 4

bilateral control of posture, walking, bending, turning (trunk and head)

both crossed and uncrossed tubers, ipsilateral and contralateral components (trying to control at midline, must control both sides at same time to maintain posture)

Question 5

what are the two ways to think about neuron function in the primary motor cortex

Answer 5

1. as individual neurones which encode for specific muscles, drection of movement, force and speed. each individual neurone has a preferred direction force and speed
2. population of neurons that code for action or sequences of action that require multiple muscles and have a goal
   ex. if stimulate monkey brain –> can induce pre programmed movements such as climbing, reaching)

Question 6

what happens when motor cortex is damaged

Answer 6

loss of voluntary movement (usually on opposite side of lesion), weakness/stiffness, aphasia

Question 7

functions of SMA

Answer 7

receives input from parietal and frontal lobes, encodes movement sequences and timing and transmits motor programs to other parts of the body

Question 8

function of PMC (premotor cortex)

Answer 8

receives input from parietal and frontal lobes and encodes relationship between effector and object, selection of appropriate motor plans

relays information to the SMA and motor cortex

Question 9

functions of pre-SMA

Answer 9

gets first input from frontal cortex (top level of motor plannig), important for deciding which action to take

Question 10

findings from single cell recording in monkeys about patterns and SMA

Answer 10

SMA encodes order of the sequence, first action of a sequence

pre SMA encordes position of a movement in a sequences, not matter the action

Question 11

function of dorsal region in the motor cortex

Answer 11

sensory to motor (what object – what action)

coding what type of action should be selected based on sensory info

Question 12

function of ventral region of premotor cortex

Answer 12

altering motor movements, specific motor commands for specific object characteristics (this is a small object, how do I adjust to grab it)

Question 13

describe methods and results of piano training study

Answer 13

let people take little piano home for 6 weeks and learn to play

brain activity wile listening to tunes they learnt to play –> greater active in dPMC, parietal cortex and SMA

hearing melody activate motor plan learned

activity in auditory cortex when listening to melodies = predictive of amount of learning

Question 14

what is coarticulation

Answer 14

one movements starts before the other is finishes, important for most skilled movement including speech, sports, music

Question 15

motor plan

Answer 15

brain representation for the movement/set of movements to be made and the prediction of what should follows said movements

Question 16

regions involved in making a motor plan

Answer 16

SMC (supplementary motor cortex) –> comes up with plan at abstract levle

premotor area –> codes for types of action tho must occur to meet plan

primary motor region –> executes motor plan

Question 17

which region do mirror neurons occupy

Answer 17

ventral most regions of the ventral premotor cortex (overlapping with brocas areas)

Question 18

what are mirror neurons

Answer 18

neurone that fire when watching someone else do an action that you have done (first found in monkeys)

maybe be important do encoding goals and intention

activity related to how close and action is to something you could do

way of encoding info form other non human creature

Question 19

initial study of mirror neurons

Answer 19

reach and grasp study in money, noticed premotor cortex neurons were firing in monkey brain when watching the researcher reach and grasp for a reward (raisin) used for the monkey

Question 20

mirror neurons in humans function

Answer 20

possibly important in learning language (think of babies imitating adults )

may help in decoding other people movements and how we should react

may be dysfunctional in autism (why they struggle to understand facial expression)

Question 21

explain study of gripping cups and mirror neurones relation to goals and intention

Answer 21

two contexts (before tea and after tea) had people view action of pick up cup with knowledge of contexts, or view actions without context

,pre activity in mirror neurons when knowing context

Question 22

is there activity in mirror neurons when watching animals make unfamiliar action (such as barking)

Answer 22

NO, mirror neurons only active for actions we ourselves can do

Question 23

study : ballet dancer and capoera dancers watching videos of both dance styles

Answer 23

when watching their own style –> greater activiety in ventral premotor cortex and dorsal premotor cortex (important for decoding movement), the parietal cortex (transforms visual info into an action from ones own perspective) and superior temporal sulcus ( becomes active when seeing movement that looks biologically human)

Question 24

study : ballet dancer and capoera dancers watching videos of both dance styles

Answer 24

when watching their own style –> greater activiety in ventral premotor cortex and dorsal premotor cortex (important for decoding movement), the parietal cortex (transforms visual info into an action from ones own perspective) and superior temporal sulcus ( becomes active when seeing movement that looks biologically human)

Question 25

function of the ACC

Answer 25

monitoring, response section, inhibition and correction systems

more important for novel actions and replacing usual action with novel action if the time calls for it

evaluates outcome of action and checks for error s (compares desired outcome with action you made)

Question 26

connections of regions in the ACC

Answer 26

posterior region connect / coactivate with the primary motor cortex (saccade, tongue, hand and foot regions)

middle region connect with SMA –> control of more complex sequences ((saccade, tongue, hand and foot regions)

anterior region connected with frontal lobe to control taks requiring more switching and conflict , hand and foot regions)

Question 27

function of parietal cortex

Answer 27

integrating action with our physical world

integrating sensory system information to frontal motor regions

Question 28

function of superior parietal lobule (dorsal stream)

Answer 28

where pathway

transform external space to body space

damage –> problems reaching, gripping, locating object in space

Question 29

function of inferior parietal lobule (ventral stream)

Answer 29

what stream

sensory motor transformation for complex learned action and specific characteristic for specific action (using bottle opener, lighting a match)

create mental model of movements (allows for adjustments, predicts how movements need to be adjusted to be achieved)

damage –> problems interacting with objects, can pretend to do an action (pantomime)

Question 30

main 3 function of the cerebellum

Answer 30

coordination

learning of motor skills

forward models (correcting errors as well)

also enhancing function of frontal lobe

Question 31

what is a forward model

Answer 31

specific version of a model for a motor plan (allows for production of action to be compared to prediction)

once a forward model is built –> don’t see much damaged to them in cerebellar damage

Question 32

true or false : cerebellum has more neurons compared to rest of brain

Answer 32

true

Question 33

organization of cerebellum

Answer 33

modulates ipsilateral muscles

more medial areas –> body center

more lateral areas –> limbs

Question 34

when does cerebellum reach peak development

Answer 34

adolescents

Question 35

true or false : cerebellum is one of the most evolved regions between primates to us

Answer 35

true

Question 36

Vestibulocerebellum (Medial regions) connection and results from damage

Answer 36

connection to brain stem, receives input from brainstem and projects back to cerebellum

damage –> impaired balance and walking

Question 37

Spinocerebellum (Anterior regions) connection and results from damage

Answer 37

receives somatosensory and kinesthetic info from spinal cord and projects back to spinal cord, involved in movement of more medial movement (coordinating trunk and leg muscles)

damage impairs walking, smooth movement and eye tracking

Question 38

Cerebrocerebellum (Lateral regions) connection and results from damage

Answer 38

receives input from temporal lobe, parietal lobe. Involved in regulation of highly skilled movement and learning

damage –> Impaired skill movement, learning, language (such as verb generation), executive function

Question 39

does cerebellar damage completely abolish movement?

Answer 39

No, but it dysregulates it, people with damage can adjust there movements, but not readjust after (treadmill effect)

Question 40

Darts study on cerebellar damage

Answer 40

2 groups, cerebellar damage and control

had to wear prism glasses which shift environment when throwing darts

control group was able to adjust once prims glasses were on, and then overshoot when glasses are off, but re adjust to get back to baseline throwing rate

damaged group was unable to compensate for prims shift, and no evidence of overshooting (which may be evidence of no adjustment or learning)

Question 41

ataxia (form of cerebellum damage)

Answer 41

poorly coordinated movement (think nose test), plan for movement disturbed and poorly timed

intention tremors as well –> shaking of lips when performing goal-direction action often overshoots

Question 42

dysarthria (form of cerebellum damage)

Answer 42

slow, slurred speech, impaired ability to control volume or pitch

Question 43

decomposition of movement (form of cerebellum damage)

Answer 43

cannot control, coordinate multiple joints

Question 44

difference between basal ganglia and cerebellum

Answer 44

Basal ganglia –> important for movement that may take time to initiate or stop

cerebellum –> movements that are not modified once they’ve been initiated

Question 45

basal ganglia function

Answer 45

The basal ganglia manage the signals your brain sends that help you move your muscles. important for initiating action

Question 46

basal ganglia function

Answer 46

preparing nervous system for voluntary acts, autopilot for when knows sequential movements, timing and switching between motor acts

helps with planning and learning for motor acts with motivational( reward )significance

Question 47

basal gAnglia organization

Answer 47

organized in a series of separable loops with cortical regions

Question 48

theory of how the basal ganglia loops work together

Answer 48

basal ganglia facilitates the cortical activity important for the selection of series of appropriate movement and inhibition of inappropriate ones

Question 49

two routs in which information passes through basal ganglia

Answer 49

direct route –> sustaining or facilitating ongoing action

indirect route –> suppressing unwanted movement

Question 50

symptoms of Parkinson’s

Answer 50

akinesia (inability to ignition spontaneous movements/bradykinesia (slowness of movement, tremors, cogwheel rigidity, disturbances of posture

Question 51

what is thought to cause Parkinson’s symptoms

Answer 51

direct pathway is compromised because putamen not receiving adeuqete input

substantia nigra also dies during Parkinson’s leading to little input to direct pathway –> leads to overactive indirect pathway –> too much activity in globus pallideus, inhibits thalamus resulting in decreased motor activity

Question 52

what is though to cause Parkinson’s

Answer 52

mix of genetic and environmental factors