Section 7 Flashcards
what are the 2 motor program theories
- motor program theory: generalized motor program
- internal framework model
what is the generalized motor program theory?
a formula that generates motor commands that produce a a group of motor skills (class of actions)
what are motor commands?
specific information needed for the movement like timing or force that the brain sends to the muscles
what are the components of the GMP and definitions?
invariant features: features of an action that remain almost the same each time it is preformed no matter the parameters
parameters: the feature of a action that change depending on the task
what is an example of an invariant feature of throwing a ball?
no matter if its over hand or underhand, the fingers are always grasping the ball before releasing
what is an example of an parameter for throwing a ball?
the speed, force and duration of throwing
what is the motor response schema and how is it important the GMP
it is how you recognize what class of actions is needed to perform the movement and how they need to be modified
what does motor equivalence tell you about the motor program theory?
that motor programs are not specific to one effector (on specific limb)
in simple words, what is the motor program?
it is the PLAN to execute the action
what are the limitations of the internal framework model?
- delay of sensory information
- noise of the sensor information
- changing of sensory information to the common coding
what is an efference copy?
a reference signal that is connected to your intended action (basically the ideal way the movement should occur)
what are the 3 types of internal models?
- cognitive
- inverse
- forward
what is the inverse model?
how the kinematics and the dynamics information needed for the movement is calculated
kinematics= joint angles
dynamics=rotation and torque
what is the forward model?
it has 2 components and works along the state estimation to find the relationship between the action and the consequences
what are the 2 components of the forward model and what do they do?
first, the forward dynamic model
- using the known movements of the body, predicts the state of the limb
forward sensory model
- predicts the sensory feedback that will occur with each movement
explain how you would explain throwing a ball using the internal framework model?
- State Estimation
- Cognitve Model: target location and goal
- Inverse Model: kinematics then dymanics
- Same time: Efference Copy to Forward Model and Motor Command to Muscles
- At Muscles: Movement occurs and sensory recpetors send feedback
- Forward model: dynamics think about how the movemnt should move and the sensory thnks about the concequences of that movemnt
- the error between the actaul feedback and the sensory predictions is called sensory predicion eroor and its entered in gain which is used to update the forward model and the predictied state
explain the credit assignment problem?
it is the opposite of the degree of freedom model
- the nervous system trying to figure out what was the error if the movement failed
- if internal, it then most figure out if it was the muscles, joints, neurons or limbs
explain the setup, goal and takeaway of the prism shift experiment
the setup was 3 conditions, no, low and high noise and within each condition there was an baseline (no shift) and adaption phase (slit shift). The goal was to see whether people would be less sensitive to the error when they had greater uncertainty. They found that people learned in the baseline trial that the feedback from vision can not be trusted so during the adaptation, they used more a forward prediction to know where the target was, resulting in smaller first adaption error in the High noise condition
how does the prism shift goggles help the understanding of the use of the forward model prediction
when feedback (visual) can not be trusted, the brain will use a forward prediction model and that causes a longer response time
how does sensory prediction error drive a correct response?
after sensing that the the prediction was off, it will quickly correct that mistake. Example, when you think the milk jug is empty but when you left it, its actually full, you quickly tighten you grip
how does the forward model help distinguish between a internally or externally generated movement
you are more aware when someone moves your limb (externally generated) than you move because to is not accounted for in the forward model
