Lecture 10

Question 1

Is it possible to trace every reflex pathway

Answer 1

no

Question 2

what could the controller be in the body

Answer 2

brain

CNS

Question 3

variables he controller uses to formulate command signals

Answer 3

control variables

Question 4

examples of control variables

Answer 4

proprioceptors
sensory
auditory
vision

Question 5

controller has the choice of _________ to peripheral info

Answer 5

reacting or not

Question 6

the controller uses independently controlled variables to formulate command signals to the lower (executive) structure

Answer 6

feedforward control

Question 7

example of feedforward control

Answer 7

soccer goalie blocking shot
line drive to pitcher
responding to tennis serve
dodge ball
hitting a ball

Question 8

feedforward control can also be simplified as

Answer 8

executing movement without using feedback

Question 9

in feedforward control, commands are generated __________ to the consequences

Answer 9

without regard

Question 10

feedforward control is also called _______ bc the sensorimotor loop is not completed by sensory feedback

Answer 10

open-loop

Question 11

what are advantages of feedforward control

Answer 11

speed, it’s very fast

Question 12

responding to a visual stimulus usually takes about how long

Answer 12

200 ms

Question 13

what is often used to start a movement such as reaching

Answer 13

open-loop

Question 14

what are disadvantages of feedforward control

Answer 14

cannot correct for errors

errors can compound

Question 15

feedback control changes command signals based on their _________

Answer 15

outcome

Question 16

how does feedback control change command signals

Answer 16

it is done by a unit termed the comparator

Question 17

changes in the output of the comparator so as to bring down any possible deviations of the output

Answer 17

negative feedback (A)

Question 18

amplifies any deviations of the output

Answer 18

positive feedback (B)

Question 19

comparing how you move to how you want to move

Answer 19

feedback control

Question 20

known as closed-loop command/control bc the sensorimotor loop is complete

Answer 20

feedback control

Question 21

feedback control uses sensory info to compare what

Answer 21

intended action/movement to the actual action/movement

Question 22

advantages to feedback control

Answer 22

• have more control bc you have sensory info

- can correct errors

Question 23

disadvantages of feedback control

Answer 23

takes more time

Question 24

ratio of change in a control variable to change in a peripheral variable (how much do you change in how you are moving) (feedback can help with this)

Answer 24

gain

Question 25

measure of time (secs or ms) (how long it takes to execute mvmnt) (how long does it take you to change)

Answer 25

delay

Question 26

a change in the delay can make an apparent negative feedback scheme function like positive feedback and the other way around

Answer 26

gain and delay

Question 27

often times the nervous system uses both _______ and ________

Answer 27

feedforward and feedback control

Question 28

when feedforward and feedback mechanisms of control are combined it is referred to as _________

Answer 28

the servo

Question 29

keeps the value of a variable specified by the controller constant despite possible changes in the external conditions that may try to change the variable

Answer 29

the servo (the feedback loop)

Question 30

example of the servo

Answer 30

a friend stops you on the way to class, controller tells you to walk faster to get to class on time

Question 31

a scheme of a simple thermostat that keeps room temp constant

Answer 31

control of room temperature

Question 32

in a servo, the longer the time delay the larger are the __________

Answer 32

errors that can accumulate before the servo makes a corrective action