Reflexes

Question 1

What will interference result in?

Answer 1

-increase RT
-increase performance errors
(ie. read red, see blue)

Question 2

Some systems of sensory feedback

Answer 2

-vestibular (ear)
-cutaneous receptors
-Golgi tendon organs
-muscle spindles

Question 3

Deafferentation

Answer 3

-caused by demyelination of large peripheral nerves
-struggle w/ touch and proprioception

Question 4

AIDP

Answer 4

acute inflammatory demyelinating polyneuropathy

Question 5

Without visual info what would you expect to see from a patient w/ deafferentation

Answer 5

-inaccurate, jerky movements
-large errors

Question 6

How does a muscle stretch impact AP’s in muscle spindles

Answer 6

-increase firing rates

Question 7

How does a muscle contraction impact AP’s in muscle spindles

Answer 7

-reduce firing rates

Question 8

How do spindle receptors sense muscle length?

Answer 8

-muscle stretch deforms and opens ion channels
-excites spindle afferent

Question 9

What produces large muscle responses?

Answer 9

-longer and larger stimuli

Question 10

Rapid force applied to the patellar tendon causes…

Answer 10

the quadriceps muscle to contract

Question 11

What increases latency in neural reponses?

Answer 11

-increased synapses

Question 12

Homonymous muscle

Answer 12

same muscle stretched by stimulus

Question 13

purpose of gamma motor neurons

Answer 13

-maintain spindle sensitivity
-maintains length of intrafusal fibres (muscle spindle) during voluntary muscle contraction

Question 14

Alternate names for long latency reflexes (LLR) inculde?

Answer 14

-long loop
-transcortical
-polysnaptic

Question 15

Describe attributes of short-latency reflexes (SLR’s)

Answer 15

-spinal proprioceptive feedback
-20 to 50ms
-simple processing capabilities

Question 16

Describe attributes of long-latency reflexes (LLR’s)

Answer 16

-spinal feedback, plus cortical (brain) feedback)
-50 to 105ms

Question 17

Describe attributes of voluntary epoch

Answer 17

-spinal, cortical and visual feedback
-longest to process (120+ms)

Question 18

Properties of SLR

Answer 18

-scale w/ background muscle activity (closer/further threshold)
-scale w/ rate and amount of muscle stretch (more AP’s, more neurotransmitters, more force)

Question 19

Properties of LLR

Answer 19

-recruit cerebral cortex
-flexible, goal-directed processing
-increase when goal is to resist mechanical perturbation (as opposed to “let go”)

Question 20

Desired state

Answer 20

-goal of task

Question 21

Motor plan

Answer 21

-aim to maintain/attain goal

Question 22

Motor command

Answer 22

-activity in motor circuits (cortical or subcortical)

Question 23

comparator =

Answer 23

brain

Question 24

Expected state

Answer 24

-intended/planned movement

Question 25

error =

Answer 25

difference btwn actual and expected state

Question 26

purpose of error signal

Answer 26

adjust ongoing movement

Question 27

closed-loop (feedback control system)

Answer 27

-uses sensory feedback to detect errors correct voluntary motor actions

Question 28

executive (feedback controller)

Answer 28

-processes sensory info -selects, programs appropriate response

Question 29

effector

Answer 29

-component of peripheral motor system -generates desired motor response

Question 30

dorsal vision stream is important for...

Answer 30

controlling actions

Question 31

ventral vision stream is important for...

Answer 31

perceptual judgements

Question 32

exteroception

Answer 32

-sensory info that tells us about the state of our body in relation to the world around us

Question 33

photoreceptors

Answer 33

-absorb photons -trigger change in membrane potential

Question 34

rods

Answer 34

-concentrated in peripheral -low visual acuity -sensitive to motion

Question 35

cones

Answer 35

-concentrated in fovea (centre) -high acuity -high spatial resolution -color vision

Question 36

dorsal stream

Answer 36

-"where" pathway -action guidance

Question 37

ventral stream

Answer 37

-"what" pathway -vision for perception (orientation), identification, recognition

Question 38

form agnosia

Answer 38

-ventral stream damage -selective impairments in perception -intact control of actions (can copy/draw, but don't know what it is)

Question 39

optic ataxia

Answer 39

-dorsal stream damage -inability to use vision to guide reaching movements

Question 40

info given by optic flow (vision)

Answer 40

-time to contact -direction of movement -movement -stability and balance -velocity of movement

Question 41

low rate of expansion (EX)

Answer 41

freighter in the distance

Question 42

high rate of expansion (EX)

Answer 42

deer in the headlights

Question 43

Rate of expansion increases as...

Answer 43

time to contact decreases (closer)

Question 44

Vision helps most with what type of movements

Answer 44

-slow, deliberate

Question 45

the dorsal visual stream gives control of what type of visual feedback

Answer 45

fast, stimulus dependent

Question 46

the ventral visual stream gives control of what type of visual feedback

Answer 46

-slower, task-dependent