lOMoAR cPSD| 46919909
Neural Basis of Motor
control Book summary
NEURAL BASIS OF MOTOR
CONTROL
, lOMoAR cPSD| 46919909
Neural Basis of Motor control Book summary
Chapter 33, 35-38 and 41-43
Chapter 33: Organization and Planning of Movement
- Voluntary movements are those that are under conscious control by the brain
- Rhythmic movements can be controlled voluntarily, but differ from voluntary movement as their
timing and spatial organization is to a large extent controlled autonomously by spine or brainstem
- Reflex movements are stereotyped responses to specific stimuli that are generated by simple neural
circuits in the spinal cord or brain stem
Motor commands arise through sensorimotor transformations
Motor outputs-> neural commands that act on the muscles, causing them to contract and generate
movement
-> these outputs are derived from sensory inputs in circuits that represent sensorimotor
transformations
Sensory inputs include extrinsic information about state of world as well as intrinsic information
about our body
- Extrinsic information can be provided by auditory and visual inputs
- Intrinsic information includes kinematic and kinetic information about our body
- Kinematic information includes position, velocity and acceleration of the hand, joint angles,
and lengths of muscles without reference to the forces that cause them
- Kinetic information is concerned with the forces generated or experienced by our body
Simple reflexes involve a simple sensorimotor transformation-> sensory inputs cause motor output
directly without intervention of higher brain centers
Voluntary movement requires multistage sensorimotor transformations
- Involvement of multiple processing centers actually simplifies processing: higher levels
Motor equivalence-> Actions are similar regardless of the limb or body segment used to produce it
-> this shows purposeful movements are represented in the brain abstractly rather than sets
of specific joint movements
How do sensorimotor transformations generate movement to a desired location?
1- Target is localized in space relative to some part of the body such as the head or arm
(egocentric space)
2- A person needs to know the initial location of the hand/object that he wishes to place on the
target
, lOMoAR cPSD| 46919909
3- Once the current configuration of the arm and location of the target are calculated,
movement is planned as endpoint trajectory-> desired change in configuration of limb expressed in
coordinates extrinsic to the limb
-> plan has to specify the path it wants to take, the successive spatial positions of the
endpoint and the trajectory/speed
-> planning the goal in kinematic terms-> desired positions and velocities of hand
-> planning the goal in kinetic terms-> force exerted by the hand
- The calculation of an endpoint from a set of joint angles is called forward kinematic
transformation
- The calculation of a set of joint angles that can reach an endpoint is termed inverse
kinematic transformation
- The motor system controls joint angles by activating muscles that produce torque (rotational
force) at the joint
-> forward dynamic transformation-> action of motor commands on muscles that results in
a set of angular positions and velocities
-> In order to make a desired joint angle trajectory, the system must convert kinetic
parameters into motor commands-> it calculates the torques at each joint necessary to
produce motion-> inverse dynamic transformation
-> to cause any acceleration, the forces applied must exceed any resisting forces
The CNS forms internal models of sensorimotor transformations
- Internal models-> neural system that mimics the behavior of the sensorimotor system and objects
in external environment
-> an internal model that represents the causal relationships between actions and
consequences is called a forward model because it estimates future sensory inputs based on
motor outputs-> predicted behaviour
Neural Basis of Motor
control Book summary
NEURAL BASIS OF MOTOR
CONTROL
, lOMoAR cPSD| 46919909
Neural Basis of Motor control Book summary
Chapter 33, 35-38 and 41-43
Chapter 33: Organization and Planning of Movement
- Voluntary movements are those that are under conscious control by the brain
- Rhythmic movements can be controlled voluntarily, but differ from voluntary movement as their
timing and spatial organization is to a large extent controlled autonomously by spine or brainstem
- Reflex movements are stereotyped responses to specific stimuli that are generated by simple neural
circuits in the spinal cord or brain stem
Motor commands arise through sensorimotor transformations
Motor outputs-> neural commands that act on the muscles, causing them to contract and generate
movement
-> these outputs are derived from sensory inputs in circuits that represent sensorimotor
transformations
Sensory inputs include extrinsic information about state of world as well as intrinsic information
about our body
- Extrinsic information can be provided by auditory and visual inputs
- Intrinsic information includes kinematic and kinetic information about our body
- Kinematic information includes position, velocity and acceleration of the hand, joint angles,
and lengths of muscles without reference to the forces that cause them
- Kinetic information is concerned with the forces generated or experienced by our body
Simple reflexes involve a simple sensorimotor transformation-> sensory inputs cause motor output
directly without intervention of higher brain centers
Voluntary movement requires multistage sensorimotor transformations
- Involvement of multiple processing centers actually simplifies processing: higher levels
Motor equivalence-> Actions are similar regardless of the limb or body segment used to produce it
-> this shows purposeful movements are represented in the brain abstractly rather than sets
of specific joint movements
How do sensorimotor transformations generate movement to a desired location?
1- Target is localized in space relative to some part of the body such as the head or arm
(egocentric space)
2- A person needs to know the initial location of the hand/object that he wishes to place on the
target
, lOMoAR cPSD| 46919909
3- Once the current configuration of the arm and location of the target are calculated,
movement is planned as endpoint trajectory-> desired change in configuration of limb expressed in
coordinates extrinsic to the limb
-> plan has to specify the path it wants to take, the successive spatial positions of the
endpoint and the trajectory/speed
-> planning the goal in kinematic terms-> desired positions and velocities of hand
-> planning the goal in kinetic terms-> force exerted by the hand
- The calculation of an endpoint from a set of joint angles is called forward kinematic
transformation
- The calculation of a set of joint angles that can reach an endpoint is termed inverse
kinematic transformation
- The motor system controls joint angles by activating muscles that produce torque (rotational
force) at the joint
-> forward dynamic transformation-> action of motor commands on muscles that results in
a set of angular positions and velocities
-> In order to make a desired joint angle trajectory, the system must convert kinetic
parameters into motor commands-> it calculates the torques at each joint necessary to
produce motion-> inverse dynamic transformation
-> to cause any acceleration, the forces applied must exceed any resisting forces
The CNS forms internal models of sensorimotor transformations
- Internal models-> neural system that mimics the behavior of the sensorimotor system and objects
in external environment
-> an internal model that represents the causal relationships between actions and
consequences is called a forward model because it estimates future sensory inputs based on
motor outputs-> predicted behaviour
