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55 Cards in this Set
- Front
- Back
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what is motor planning? what is motor control? |
motor planning - ability to organize the body's actions, knowing what steps to take and in what sequence to complete a particular task motor control - involves generating motor commands, predicting the sensory outcomes of those commands, and using errors to guide and update movements on the fly |
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what is the major assumption that all neuroscientists make about how behavior is controlled? |
assumptions that the complex behaviour (perceptions, thought and actions) of animals depends on physical process in the central nervous system |
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what are the two major divisions of the CNS? |
brain and spinal cord |
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what are the sensory and motor decussations and where are they located? |
sensory decussation - crossover of axons from gracile nucleus, responsible for fine touch and proprioception motor decussation - in the anterior median fissure of medulla oblongata |
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what are the major divisions of the brain stem? |
pons, medulla, midbrain |
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what are the three major components of the cerebrum? |
basal ganglia, limbic system and gray and white matter of cerebral cortex |
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how does the limbic system contribute to motor control? |
may play role in motor planning and trigger defensive responses |
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list the four lobes of the cerebrum |
frontal, parietal, temporal and occipital |
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what layer of the cortex is most associated with afferent information? with efferent information? |
layer 4 - thalamocortical afferents and intrahemispheric corticocortical afferents layer 3 - principal source of corticocortical efferents |
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what are the major cortical features and landmarks? |
right and left hemisphere interhemispheric, central, lateral fissure frontal, parietal, occipital, temporal lobe 3 poles corpus collosum commissure |
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where is the primary motor cortex? what areas project to the primary motor cortex? |
precentral gyrus, main sensory receptive area for the sense of touch |
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where is the premotor (and supplementary motor) cortex? what areas project to the premotor cortex? |
superior frontal gyrus anterior to precentral gyrus, receives sensory information from parietal cortex, motor information from basal ganglia and cerebellus, and sends signals to M1 |
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what is the major assumption of the lesion method? |
if brain area x is involved in motor performance, then damage to x will lead to movement impairment, the nature of the movement impairment may reveal that brain area's role in performance |
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what is the major assumption of the activation method? |
if brain area x is involved in movement performance, then area x will be more active when people perform a movement task than when they perform some other task |
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what is the function associated with the premotor cortex? how do we know? |
premotor cortex (PMC) receives sensory information from parietal cortex, motor information from basal ganglia and cerebellum, and sends signals to M1, generates motor command monkey study - moving lever towards light, electrode from motor cortex neurons to recording device, neurons preferred direction of movement |
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what is the primary function associated with the motor cortex? how do we know? |
primary motor cortex (M1) generation and execution of motor command, sends efferent motor signals to the spinal motor neuron pool via cortical spinal tract monkey trained to resist force applied by weight, M1 cell firing rates were modulated by force level |
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identify and label parts of the basal ganglia |
caudate nucleus, putamen, thalamus, internal capsule, basal ganglia |
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what are the 4 major cortico cortical circuits and what are their function? |
skeletomotor - voluntary movements, balance and gait oculomotor - eye movement control limbic - emotion control and motivation prefrontal - planning, persistence, memory, spatial ability |
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what influence does the direct route have on cortical function? what the direct route is dysfunctional, how is movement affected? |
net cortical excitation, reduce inhibition from BG, movement initiation and maintenance, striatum inhibits the GPi disease interferes with: akinesia (lack of move), bradykinesia (slowness of movement), poor balance |
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what influence does the indirect route have on cortical function? when the indirect route is dysfunctional, how is movement affected? |
net cortical inhibition, increase the inhibition from BG, stratium and STN excite the GPi, stopping and stillness disease interferes with: resting tremor, rigidity (muscle stiffness) |
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spell and define the 5 major signs of cerebellar disorders |
hypotonia - reduction in the readiness to move ataxia - abnormal execution of multi joint move, lack of coordination abasia - loss of ability to maintain upright stance dysdiadochokinesis - inability to perform alternating moves intention tremor - inability to stop movements without oscillating around end location |
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what kind of information does the cerebellum store about your body? |
stores memories of weight and length, allowing proper motor command to be generated |
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describe features common to all pathways? |
carry information to and fro within the brain, and between the brain, cerebellum, spinal cord and peripheral nervous system |
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what pathways are used to communicate between hemispheres? |
inter hemispheric connections across corpus callosum to homotopic points |
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what types of pathways are used to communicate within cerebral hemispheres? |
interneurons |
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what kind of information travels in ascending pathways? |
carry sensory information (touch, proprioception, pain, temperature) from environment and body to brain, vision and somatosensation |
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describe the major visual pathway |
visual neural system begins in the retina (back of eye) at the visual receptors, detect wavelengths and transduce light energy to electrical signal |
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describe the two major intracortical visual streams? |
dorsal stream - from V1 to parietal cortex and motor areas of frontal cortex, important for processing targets for actions, hand and eye ventral stream - from V1 to the temporal cortex, important for recgonizing objects, faces, places, using vision to understand speech |
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what is posture? |
ability to control our body's position in space for the purpose of maintaining orientation and stability |
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what is postural orientation? what is postural stability? |
postural orientation - ability to maintain the relationship between body segments and between the body and the environment postural stability - our ability to keep the centre of mass within the limits of our base of support |
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define and distinguish between centre of mass, centre of gravity, and centre of pressure |
COM: point in 3D space that is at the centre of the total body mass COG: the vertical projection of center of mass down to floor COP: the center of the distribution of forces applied to the support surface |
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what is the base of support? |
BOS - area of the body that is in contact with the support systemh |
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what is the relationship between COM, COG, COP, and BOS when balance is being maintained? what has happened when someone needs to take a step to keep from falling? |
when balance is being maintained COM, COG, COP and BOS are within the same spot when someone needs to take a step to keep from falling the COG is outside the base of support |
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what groups of muscles contribute to the maintenance of balance during quiet stance? |
activity in antigravity postural muscles increases to counteract gravity same muscle synergies used during perturbed stance also play a role in maintain quiet stance |
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how does sensory feedback contribute to the maintenance of balance? |
sensory feedback from unexpected perturbation triggers postural responses, compensatory or reactive postural responses |
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what are the three main reactive postural adjustments? |
ankle strategy- body sways at ankles with hips and knees extended, small perturbation and support platform firm hip strategy- bigger perturbation, more metablic energy, produces large, rapid motion at hip joints, used for standing on narrow BOS stepping strategy- natural response, not a last resort balance |
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what is the sensory weighting hypothesis? |
postural control system is able to reweight sensory inputs in order to optimize stability |
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what are the three main sensory systems contributing to balance? |
vision somatosensory vestibular |
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how does a secondary cognitive task during a balance activity affect balance? |
as the difficulty for maintain stability increases there is an increase in sway, greater destabilization |
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define and distinguish between gait and locomotion |
gait: manner in which a person walks, characterized by rhthym, cadence, step, stride and speed locomotion: behaviours characterized by rhythmic, alternating activity of opposing limbs on body |
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what are the three essentials for successful locomotion? |
progression - achieved through move in desired direction postural control - need to maintain appropriate posture adaption - to goals of mover and conditions of environment |
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what are the major landmarks in the gait cycle? |
stance - interval for foot of reference to be in contact with ground swing - interval foot is off ground stride - distance of a full gait cycle step - distance from heel strike of one foot to that of other foot speed - stride length and cadence |
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what is the relationship between speed, energy expenditure and gait pattern? |
effect of speed on gait show energy expenditure increases with speed but switch to new gait pattern associated with decrease in energy expenditure, running is less energy than it is to walk fast, new gait pattern allows speed that are unachievable in former gait |
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gait can also be measured using relative phase plots? what is a relative phase plot and what is the major advantage they offer clinicians and researchers? |
plot how the thigh rotates against how the knee rotates, allows to see whole gait cycle, observe gait differences |
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provide a definition for reaching |
all about what direction and how much distance to go, process of transporting the hand to the target location |
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provide a definition of grasp control |
using object size/weight information to determine grip size, grip type and grip force |
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provide a definition of prehension |
action of grasping or seizing object |
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what happened to DF? where were her lesions? how did these lesions affect her ability to perceive objects, faces and scenes? how did these lesions affect her ability to reach for, orient to and grasp objects? |
gas leak causing loss of consciousness couldn't see properly, couldn't recognize anyone bilateral lesion in ventral stream visual form agnosia - inability to use vision to determine shape cannot recognize orientation, can orient her hand to pose a block |
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what happened to RV? where were her lesions? how did these lesions affect her ability to perceive objects, faces and scenes? how did these lesions affect her ability to reach for, orient to, grasp objects? |
stroke affecting right posterior parietal cortex, second stroke affected her left PPC can report location of items and can point to locations on her skin but moves hand to incorrect locations, can see and verbally report orientation and size, but fails to correctly orient and size her hand when moving optic ataxia - inability to use vision to determine location and size for reaching and grasping |
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what do the case studies of DF and RV tell us about how perception and vision for action are instantiated in the brain? |
dorsal stream provides vision for action ventral stream provides vision for object recognition |
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what happens in the intraparietal sulcus? |
specifies target location with respect to the eye, head and hand lateral (LIP) - tracks where target is on retina ventral (VIP) - tracks where target is with respect to the head medial (MIP) - tracks where a target is located with respect to current hand position anterior (AIP) - tracks target size for grasping |
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how do we know that reaching direction is coded in the premotor and primary motor cortex? |
monkey study - use of sensory information about the position of the target to specify movement direction, recorded single neurons in PMC and M1 while monkeys made movements in different directions |
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how do we know that reaching distance is coded in the primary motor cortex? |
monkeys trained to resist force applied by weight and gravity while single cells were recorded, M1 cell firing rates were modulated by force level |
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what kinds of measures can we get from hand path kinematics? what can we learn by studying time to and time after peak velocity? |
y position and x position start, accelerate, peak velocity, decelerate, stop time to peak velocity: ballistic stage that depends entirely on the planned motor command time after peak velocity: all time people spend decelerating towards target, sensory feedback used to update and improve movement |
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define and distinguish between grip size, grip type and grip force |
grip size - distance between thumb and index fingers, tuned to object size grip type - determined by goal, size and weight of object, differ by number of fingers and position of thumb grip force - tuned to force load |
