Movement And Execution Flashcards
What are the pros of a feedforward controller
1.movement can be controlled without gathering/processing any external information: good for fast movement
What are the cons of a feedforward controller
- Error made by controller accumulates over time
2.no flexibility to environmental changes
3.high cost of planning no generalisation
Feedforward controllers in human motor control
Ballistic, open loop control is needed to generate very quick movement, when there is no time to process sensory feedback.
Feedforward control is mostly used for eye movement whose inverse model is relatively simple.
Feedforward control is also used in the initial part of the movement before the sensory feedback kicks in
Feedback controllers pros
1.flexible: can deal with unexpected events
2.robust: control error does not accumulate over time
3.general:control is invariant to starting or goal position
Feedback controller cons
1.processing sensory feedback can take time so not good for fast movement
2.controller can become unstable when sensory feedbacks are noisy
3.can become unstable when feedbacks are delayed
Strategies to compensate for sensorimotor delays
Prediction compensates for sensorimotor delays, if u know what is going to happen in the future, as a consequence of ur own action, u can proactively control ur movement based on the prediction
Forward model enable anticipatory control:
The forward model predicts the consequence of an action based on the efference copy.
You can anticipate what sensory feedback will be received before it arrives
Observer model: what is the optimal way of planning my action
What is the forward dynamic model?
What is the forward sensory model?
Forward dynamic model: what is my current status (position, velocity,joint angles)
Forward sensory model: in that status what sensory info am I supposed to sense
What does the forward internal model enable
It enables prediction, by which our brain does anticipatory control of the movement
