4. Action Flashcards
motor programs
- the plan to produce a particular motor action that occurs independently of the effectors used to carry out the movement
lower motor neurons
- also called primary motor neuron
- directly innervates muscle
local circuit neurons
- also called interneuron
- neurons local connections contribute to processing circuitry
upper motor neurons
- a neutron that gives rise to a descending projection that controls the activity of lower motor neurone in the brainstem and spinal cord
primary motor cortex
- essential for voluntary control of movement
- located in the percentile gyrus
premotor cortical areas
- includes premotor cortex, supplementary motor cortex, and parts of the parietal cortex that provide motor programming signals to the primary motor cortex
premotor cortex
- part of the prefrontal cortex
- involved in planning movement
supplementary motor cortex
- premotor area that plays an important role in movement planning at a conceptual level
- particularly when plans involve internally generates sequences of actions (tying shoelaces, playing a song on the piano)
medullary pyramids
- longitudinal bulges on the ventral aspect of the medulla that signify the corticospinal tracts at this level of the nervous system
frontal eye fields
- associated with area 8a, plays a key role in voluntary visual orienting movements
superior colliculus
- paired structures that form part of the roof of the midbrain, important in orienting movements of the head and eyes
saccades
- ballistic eye movement that changes the point of binocular visual fixation; normally occur at a rate of about three to four per second
readiness potential
- electrical potential that signals the intention to initiate a voluntary movement well in advance of actual production of the movement
anosognosia
- lack of awareness at ones own disability
reward value
- the likelihood that a particular movement will yield a reward, multiplied by the amount of reward expected
optic ataxia
- neurological condition associated with damage to the dorsal parietal cortex and characterized by deficits in visually guided reaching
basal ganglia
- made up of the caudate and putamen ( striatum) and the globes pallidus
substansia nigra pars reticulata
- component of the midbrain substantial nigra nucleus that plays a key tool in the suppression and initiation of saccadic eye movements
parkinsons disease
- neurodegenerative process affecting the substantial nigra that results in a characteristic tremor at rest and a general paucity of movement
huntingtons disease
- an autosomal dominant genetic disorder in which a single gene mutation results in damage to the nasal ganglia that causes personality changes, progressive loss of the control of voluntary movement, and eventually death
choreiform movements
- uncontrollable writhing or twisting associated with damage t the basal ganglia, occurs in huntingtons disease
hemiballismus
- a neurological disorder resulting from unilateral damage to the basal ganglia; manifested by flinging movements of the limbs contralateral to the lesion
cerebellum
- concerned with motor coordination, posture, balance, and some cognitive processes; composed of a three-layered cortex and deep nuclei
intention tremor
- a tremor that occurs during performance of a voluntary motor act
somatic action
- skeletal muscles : move limbs
autonomic
- smooth muscles: change BP, digest food
- cardiac muscles: heartbeat
- endocrine glands: secrete hormones
- exocrine glands: secrete sweat, saliva
the inverse problem
determining what actions to take in order to achieve goals
inverse models
current position and desired position : motor commands
- used to create motor plans
forward models
- current position and motor controls: predicted position
- used to evaluate motor plans and/or action
feedforward control
-motor command sent to muscle, faster, but less accurate than feedback control
feedback control
- motor command sent to muscle, actual state compared to a desired state, adjustments made based on errors
- slower but more accurate than feedforward control
