Cognitive: Motor control and Action Flashcards
What is included in the motor system?
Components of the central and peripheral nervous systems along with the muscles joints and bones that enable movement.
What did Woodworth’s study set to prove and what did it require of the participant?
That there are different stages to motor control and participants had to slide a pencil back and forth between targets.
What did the data from Woodworth’s study reveal?
Movement between targets could be described with a two-component process of motor control. The impulse phase initiated the movement and was planned in advance of the start of the movement and this plan would be sent from the brain to the body in the form of a motor command. In the control phase vision was key to controlling the accuracy of the final endpoint position.
What is the motor control problem?
How to get the body from one posture to another.
What is meant by the degrees of freedom of a joint?
The degrees of freedom of a joint are the number of ways it can move.
What is the degrees of freedom problem?
The structure of joints and muscles in the body provide a redundant system, when performing a task the joints do not need to all move in all ways. (elevator button)
What is meant by the inverse problem of vision
When there are more than on interpretation of the 3d world given the 2D image information.
What is the Equilibrium point hypothesis?
A theory of motor control that emphasizes how the problem of control can be simplified by taking into account muscle properties
Where does the equilibrium point hypothesis place emphasis
The special relationship between the brain and the muscles
Given an alternative name for this type of model, why is this?
Mass spring model because it reflects the intuition that the amount of force our muscles can exert depends on how much they are stretched.
What does any stable posture require according the the equilibrium point hypothesis?
The setting of various control parameters for muscle activation to achieve stability.
What criticisms has the EP hypothesis faced?
It is only suitable for certain ranges of movements and muscle properties.
What is meant by the dynamic systems hypothesis
An approach to motor control which emphasizes interaction between the body and environment and uses special mathematics that describe how a system’s behaviour changes over time.
Give two examples of state transitions
Walking and running are distinct motor patterns and there isn’t an inbetween state. When we move two limbs together there is a tendency for them to exhibit mirror symmetric movements. (fingers)
What strengths tie these two theories together?
Makes clear the brain can simplify its planning by knowledge of the body and has likely been driven to particular solutions through interactions with the environment.
What is meant by the optimal control theory?
It provides a framework for implementing principles that produce movements that optimally satisfy some criterion. It views motor control as the evolutionary or developmental result of a nervous system that tries to optimize organisational principles.
What is the function of a forward model?
Predicting the relationship between between actions and their consequences.
Describe in detail the optimal control theory cycle
First the control policy takes as input the current state estimate and outputs a motor command. It provides a set of rules that determines what to do given a particular goal and state estimate. The motor command contains information about how the body is supposed to move. Physiological noise is introduced into the motor command due to imperfect neural transmission along the pathway from brain to body. The forward model then takes as input the motor command and outputs a prediction of the sensory consequences of the motor command. The body then takes as input the motor command that has been degraded by noise and produces an action that changes the state of the body and typically also the world; this creates new sensory information.This sensory information is also corrupted by noise arising from imperfect sensing and neural transmission. This noise will lead to uncertainty in estimating the state of the body and the world. Sensory integration then takes as input all the sensory information as well as the prediction of the forward model and outputs an estimate of the current state of the system which provides an internal representation of the current state of the body and world and is input to the control policy.
What makes the optimal control theory ideal for cognitive psychology?
It heavily influenced by the forward model and the reliability of sensory information rather than physiology or the relationship between an organism and the environment.
What brain areas align with the aspects of functions of the Control policy, Forward model and sensory information?
Control policy- basal ganglia
Forward model- Cerebellum
Sensory integration- parietal cortex
What was Wolbert’s hypothesis of his experiment
We reliably underestimate the forces we produce.
What was the procedure of Wolbert’s experiment
There were three conditions. In the first there were 6 pairs of participants. A small torque motor applied a small amount of pressure to the left index finger of one participant. Participants then took turns attempting to mimic the pairs force using their right index finger to push their pair’s left. In the second condition they had to match it by pushing against their right index finger. In the third they had to manipulate a joystick that controlled the amount of force applied to the left index finger.
What were the results of Wolbert’s experiment?
1st condition: Force went up38% per turn
In the second participants consistently used more force. The third condition was much more accurate.
Why may schizophrenic be better at scaling the pressure they’re applying.
They often think the actions they’re performing are of alien origin therefore they do not treat these actions as their own and do not treat them different.
