movement planning and execution Flashcards
what is localisation
representation of the location of an object
what is planning
plan of reaching based on the location
what sensory info is required for the destination when localising and planning
extrinsic info
visual info
auditory info
what sensory info is required in action
intrinsic info - kinematic/kinetic info
muscle spindles - length and velocity of each muscle
Golgi tendon organs - force produced by each muscle
mechanoreceptors - force on skin
what does voluntary movement require ?
high levels of cortical control
generates a plan which turns to muscle contraction
why is sensory motor control hierarchal ?
going from general plan (extrinsic) to motor commands in intrinsic space requires multistage sensorimotor transformations
name elements of sensorimotor transformations
movement planning - localisation and planning
inverse kinematics - how to move the body
inverse dynamics - torque in joints
what are the extrinsic coord systems
allocentric/ egocentrics
exteroceptive(sensory) info
what are the intrinsic coord systems
joint angles
muscle lengths
proprioceptive info
what coordinate systems are used after localisation
hand centred
eye centred
what is relevance of the posterior parietal cortex (PPC)?
anatomical proximity of LIP, PRR, AIP indicated PPC plans movement by closely coordinating the eye and the hand
LIP: saccadic eye movement
PRR: reaching
AIP: grasping
what is directional tuning ?
neurone in primary cortex have a preferred directions
why is feedforward control useful
generate quick movement when non time to process sensory feedback
mostly used for eye movement
why is feedback control useful
good for movement that requires little latency
VOR
good for movement with complicated dynamics
how does delay effect feedback ?
eyes/visual : 100 ms to process in retina and transmit to vis cortex
muscles/reflexes: 10-40 ms before muscle spindle reaches CNS
