Lec 8 - 10 Flashcards
1
Q
what are the peak events in muscle activity
A
- M1 wave: short latency
- M2 wave: long latency
- M3 wave: voluntary response
2
Q
What are the characteristics of the M1 wave?
A
- short latency, monosynaptic reflex
- kicks in at 30ms
- involves spindles and the same muscle that sent info
- simple
- not modified by instruction
3
Q
what are the characteristics of the M2 wave?
A
- long latency
- hits at 50-80 ms
- sensitive to goals. without it, M2 disappears
- receives input from from higher brain centres
- involves spindles, cortex/cerebellum and same muscles
- complex
- modified by instruction
4
Q
describe the characteristics of the M3 wave
A
- voluntary response
- 120-150ms
- involved various receptors, higher centres and various muscles
- modified by instruction
- not a reflex response
5
Q
which of the peaks in muscle activity are modified by instruction?
A
M2 and M3
6
Q
which of the peaks in muscle activity use the same muscles that sent info?
A
M1 and M2
7
Q
which of the peaks in muscle activity hits 50-80ms after (stimulus onset?)
A
M2
8
Q
which of the peaks in muscle activity hits 30ms after onset
A
M1
9
Q
which of the peaks in muscle activity hits 120-150ms after onset
A
M3
10
Q
What is the response time for M1
A
30ms
11
Q
What is the response time for M2
A
50-80ms
12
Q
What is the response time for M3
A
120-150ms
13
Q
define muscle spindle
A
muscle spindle: a type of sensory organ that is sensitive to muscle fibre length changes, as well as its rate of change
14
Q
describe the muscle spindle
A
- spindle shaped
- oriented parallel to fibres
- sends info to spinal cord
- can excite motor neurons
- 1a afferent hook up
15
Q
What is the monosynaptic route
A
1a afferent of muscle –> motoneuron in spinal cord –> muscle
16
Q
describe the GTO
A
golgi tendon organ: a type of sensory organ that detects muscle tension/force
17
Q
where are GTOs located
A
between muscle and tendon
18
Q
why are GTO important
A
GTO are important for injury prevention by detecting and sending information regarding muscle tension
19
Q
Describe the route of proprioceptive reflexive closed loop control
A
You still have the executive and effector, along with spindles (from muscle to spine/motor program), GTO (muscle to spinal cord) and vestibular/joint/cutaneous afferents (goes to comparator)
20
Q
what is the vestibular system?
A
vestibular system: a sensory system in the inner ear that is important for balance and proprioception
21
Q
what are the components of the vestibular system
A
semicircular canals and otolith organs
22
Q
what do the semicircular canals detect
A
angular acceleration
23
Q
what information do the otolith organs detect
A
linear acceleration
24
Q
what are the different types of otolith organs
A
utricle and saccule
25
what information do cutaneous receptors detect
information regarding touch, pressure, temperature etc.
26
define joint receptor
joint receptors: a type of receptor that detect joint position and movement
27
what is interesting about the firing of joint receptors
they fire at the end of movements, very few can code for the middle
28
where are joint receptors located
within joint capsules
29
what sense has a more conscious AND reflexive control component
vision
30
how is vision both conscious and reflexive?
conscious - exteroceptive feedback post movement goes to the input
reflexive - exteroceptive feedback post movement goes to motor program
31
what is the preferred source of sensory information
vision
32
what are the two visual streams of processing
1. dorsal
2. ventral
33
describe the dorsal visual stream of processing
- non-conscious + quick, works without our awareness
- goes from back of head to front of head
- important for navigation and movement control
- involves entire vision field
- goes from movement -> motor program
- important for minor adjustments
34
what are the problems associated with dorsal visual stream?
1. optic ataxia: causes patients to miss objects when trying to grab it. we see this issue when we are moving, when you have to integrate sensory information with action
35
describe the ventral vision stream
- conscious + slow
- back of head to down
- good for stimulus identification, knowing what you are grabbing
36
what are the problems associated with the ventral visual stream
visual form agnosia: capable of identifying objets only when moving or when able to touch it. Otherwise they cannot recognize what they are looking at
37
which visual stream is slow?
ventral
38
which visual stream is important for navigation
dorsal
39
which visual stream involves the entire vision field
dorsal
40
which visual stream is associated with optic ataxia
dorsal
41
which visual stream is fast
dorsal
42
which visual stream is important for object identification
ventral
43
how do we know that there are two streams of visual processing?
1. Brain injury dissociation (optic ataxia and visual form agnoxia)
2. Visual dissociation (ebbinghaus illusion)
44
what is the ebbinghaus illusion
ebbinghaus illusion: an optical illusion that makes objects appear larger or smaller depending on the size of the objects around them
45
what is some evidence for fast vision for action (dorsal) regulation of motor control
1. avoidance/navigation
- dorsal vision provide info about time to contact, AKA the rate of expansion on the retina
2. Balance control
- swinging room - movement creates optic flow patterns, where kids compensate for a moving room with their own motion
46
describe the results of the swinging room experiment
adults - didnt show change when standing, until tasked with a beam. at this point, they fell over a lot more.
children - moving the room towards baby = falling backwards. moving room away from baby = falling forwards
47
what sense dominates other proprioceptive sources
vision
48
what is the mcGurk effect
McGurk effect: an illusion that occurs when what we see does not match what we hear
49
what are the types of visual closed loop control
1. conscious closed loop
- ventral vision
2. non-conscious closed loop control
- dorsal vision
50
On the closed loop, at what level of the motor system are spindles located?
muscle!
51
Summarize the textbook's chapter about anti lock brakes
52
Define a motor program
motor program: a pre structured set of neural commands that are capable of movement without the influence of feedback
53
where are movement representations stored
memory
54
describe how movement representations change based on experience?
Movement is extrapolated from our past experiences, so depending on our level of experiences, our movement will vary. it is dependent on context and memory
55
What are the motor program loop components
1. executive = information processing
2. effector = represents muscle,
56
where are motor programs prepped?
in the executive, from long term memory
57
what connects the executive and the effector?
long term memory
58
summarize the types of empirical support for motor programs
1. RT and movement complexity = RT increases with complexity
2. Inhibiting anticipatory actions = prepackaged actions cannot be interrupted3
3. Triphasic EMG pattern and movement blocking
4. Startle effect
59
Pre structured movement is connected to which type of empirical evidence for the existence of motor programs
RT and movement complexity (but i think its all of them since pre structured movement is the whole idea behind motor programs)
60
what type of evidence is a stopping task associated with?
evidence for the existence of motor programs - more specifically for inhibiting anticipatory actions
61
what are coupled units
actions that appear together, like in baseball hitting, step + swing --> trunk + shoulders is a coupled unit
62
what is the PONR
PONR: the point of no return: the point/time where there is a 50% probability of initiation
63
What do we call the point in time where there is a 50% probability of initation?
the point of no return
64
how do we adjust the point of no return to be more accurate (?)
if we know the error of a task, we add the constant error to the PONR
65
During what period of RT do we select a program and wait to initate?
the anticipatory period
66
After the PONR, which loop is used for the motor program?
open loop
67
How do the loops used for motor programs change from initial execution to stopping/altering
changes from open loop to closed loop
68
which loop is required for altering a motor program? Why?
closed loop - because contrary to open loop, it takes in sensory feedback which is necessary alter movement
69
is it more difficult for novices or experts to inhibit preplanned actions - why?
experts, since they use open loop more often than novices
70
what is meant by triphasic pattern? what are its components
triphasic pattern is the sequence of muscle activity during movements
1. agonist 1
2. antagonist 2
3. agonist 2
71
what is agonist 1 of triphasic pattern
agonist 1: main impulse of movement, precedes movement onset
72
what is antagonist 2 of triphasic movement
antagonist 2: deceleration of the limb
73
what is agonist 2 of triphasic pattern
agonist 2: clamps limb for co contraction, essentially fine tuning and stabilizing the limb
74
what is the blocking paradigm, and which piece of empirical evidence does it correspond with?
blocking paradigm: a model that blocks contractions/movement
Associated with triphasic EMG pattern evidence, showing that triphasic pattern does not change even with blocking, supporting the idea that movements are prepackaged
75
Who is Ian waterman and why is he important
He was a man that contracted a viral illness that attacked his nervous system, causing him to lose all proprioception and sensory transduction
76
under what conditions would we see a change in the triphasic pattern
We don't see much of a change. if we block the movement, there is a similar pattern, with agonist 1 and antagonist 2 occurring at the same times as unblocked movement.
77
What is the start react effect
when a loud/startling tone results in the release of a prepared movement, most often with a reduced RT
78
How loud does an acoustic startle response have to be?
above 90db
79
what muscle contraction results in neck clenching
contraction of the sternocleidomastoid
80
how early do we see a startle response after onset of stimulus?
50-70ms
81
What would we expect in startle trials when the person is ready to make an extension movement? Would we see only startle response, or both startle and extension with an RT that is the same or faster
we would see both the startle and the extension, with a faster RT
82
How do we know that the startle effect is not just an example of a stimulus intensity effect?
The startle effect is not anticipated, unlike the stimulus intensity effect, which is oftentimes spatially/temporally anticipated by the participant waiting to unload a movement
83
would we see a start react effect during choice reaction tasks?
NO! Only when the movement is preplanned do we see a reduced RT
84
what are motor programs synonymous with?
open loop control
85
do most movements use open loop, closed loop, or both?
both
86
what are the pros and cons of motor programs
pros
1. Great for fast actions - you dont have to wait for feedback
2. Many degrees of freedom - provides a way of coordinating actions
cons
1. storage problem
2. novelty problem - how do we program when some factor is changed?
87
define degrees of freedom
degrees of freedom: an indication of how many ways a system can move (freely)
88
how many degrees of freedom are there in a baseball pitch, with shoulder, elbow, radio ulnar and wrist joint?
shoulder = 3 df
elbow = 1 df
radio-ulnar joint = 1df
wrist joint = 2 df
89
what is a potential solution to the cons of motor programs?
generalized motor programs - invariant features solve the storage problem, and parameters solve the novelty problem
90
what are generalized motor programs
GMP: memory for a class of actions that can be modified based on the desired outcome. They act as a template for a general action that is fine-tuned
91
Define the two features of general motor programs
Invariant feature: the fixed feature that defines the motor program, solves storage problem
parameter: flexible features that define how the motor program will be executed, solves the novelty problem
92
where in information processing is the GMP selected?
response selectionw
93
where in information processing are parameters selected?
response selection
94
which is selected first, GMP or parameters
GMP, then parameters
95
Where in information processing are parameters assigned to the GMP to be initiated
response programming
96
what occurs with the GMP during response selection
both GMP and parameters are selected
97
What occurs with the GMP during response programming
Initiation of parameters to assign to GMP
98
What is some simple evidenced (discussed in class) for GMP evidence?
By writing your signature 5 times with dominant/non-dominant hand, backwards etc., we can see that generally they are similar but have a lot of differences. this gives evidence for a general motor program, instead of separate versions of a program
99
How do we identify general motor programs?
Invariant features!
1. relative timing
2. relative force
3. order of events
100
what identification of GMP is the most important?
relative timing
101
describe relative timing as an identification of GMP
relative timing: the proportional, internal rhythm of a skill, where the stages of each action remain proportional and fixed. relative timing is invariant.
102
Do we look at parameters or invariant features to identify GMP?
invariant features
103
describe relative force as an identification of GMP
relative force: the amount of force produced by muscles, which remains in constant proportion from movement to movement
104
"If muscle 2 force is twice that of muscle 1, that remains constant if it is the same GMP" is an example of what kind of identification?
relative force
105
describe order of events in GMP identification
order of events: the order of action components/steps are fixed.
106
"Muscle #1 will always be active before muscle #2" is an example of what kind of GMP identification?
order of events
107
what thing satisfies storage and novelty problems
General motor program - separately invariant features and parameters
108
which is more consistent across a range of variables: invariant features or parameters
invariant features i think
109
Invariance shows up in the form of 3 components. what are these components
1. relative timing
2. relative forces
3. order of elements
110
define parameters
parameter: features supplied to the GMP that are flexible and define how to produce unique events
111
which are tunable, invariant features or parameters?
parameters
112
what are the types of parameters?
1. Absolute movement time
2. Absolute force
3. Effectors (muscle selection)
113
Is the proportional timing of absolute duration invariant of parameter?
invariant - relative timing remains invariant, but can be scaled for longer or shorter movements
114
What is movement amplitude (or absolute force) proportionate to?
acceleration. Increasing amplitude results from uniformly increased acceleration/forces
115
what do we examine to see if forces are proportionate across different movements
acceleration traces
116
describe effectors as a parameter
effectors: muscle selection! The same motor program can be executed by different limbs or muscles
117
how do we select parameters
- select force amount and duration
- use knowledge of past experiences
- schemas
118
define schema
schema: a relation between parameters and outcomes (memory)
119
What are GMPs adapted to?
schema
120
What component of GMP is the scaling factor
parameter
121
what component of GMPs are the signature of the action
invariants
122
schemas get better with what?
experiences!
123
Explain how parameters solve the novelty problem
parameters extrapolate from past experiences
124
how are stopping tasks different from blocking tasks
Stopping task = hold down a button until the clock reaches 10, do not respond if it stops before the target.
- discusses the point of no return, where YOU cannot stop your own action
blocking task = researcher blocks participant movement, to examine EMG pattern.
- your action is stopped by someone else
125
what is the average premotor Rt and startle premotor RT?
Average premotor Rt = 95ms
Startle premotor RT = 64ms
126
Which muscle peak is simple
M1
127
which muscle peak is complex
M2 and M3
128
Which feature of the GMP use schema?
parameters
129
in what situation might we not see the startle react effect
during a choice reaction task
130
describe how RT and movement complexity serve as evidence for general motor programs
It supports the idea of prestructured movement. In the Henry and Rogers experiment of finger tapping, showing that whole movements were programmed before initiation
131
what are ceiling and floor effects not sensitive to
group differences
132
Why do we want to avoid floor and ceiling effects?
Because any changes in performance become increasingly internally driven
133
what is the mcgurk effect
mcgurk effect: an illusion where what you hear doesn't match what you see
134
Define blindsight
blindsight: a medical condition in which the person can respond to visual stimuli without conscious perception
135
define quiet eye effect
quiet eye effect: the effect that longer eye fixation has on improving performance, typically seen in experts
136
why is visibility in night time car truck accidents an issue
because of the rate of expansion - within a certain distance, you cannot sense what the rate of expansion is telling you before it is too late
137
What sensory information does not provide proprioceptive information to a performer
optical flow! It is related to estimating time to contact
138
The M1 feedback loop is at a low level in the spinal cord and does not involve _____
voluntary control
139
visual information travels from the retina to what part of the brain?
primary visual cortex
140
The dorsal stream is know as the (where/when) stream
where
141
the ventral stream is also known as the (where/when) stream
when
142
What postural response would you expect if a swinging room swings towards a toddler
they would fall backwards
143
What is the henry rogers experiment
an experiment in which participants would respond as quick as possible to a stimulus by making one of three movements. it found that movement complexity increased RT
144
in the case of fraud, with forging signatures and entering a password, what invariant feature is missing from these
relative timing
145
what is the stereo system an analogy for?
for GMPs! The main turntable is the GMP storage, and the speakers are the limbs that carry it out
146
what result in the movement blocking paradigm helps to support the existence of motor programs?
the result that the antagonist muscle triphasic EMG pattern does not change. Shows that proprioceptive information does not change the response
147
what specific feature of the GMP would have to be tuned to account for a slight difference in distance when free throwing
amplitude or overall force
148
experimenters have shown that RT can be affected by factors taking place during which stage of information processing
response programming
149
Schemas show the relation between outcomes and _____
parameters
150
describe the roles of open loop organization in motor programs
1. program postural adjustments
2. organize degrees of freedom
3. engage in response selection and programming
4. modulate reflex pathways to ensure achievement of the desired goal
151
fitts law states that the ______ is linearly related to the index of difficulty
movement time
152
effective target width is a measure of what?
accuracy (standard deviation)
153
The relationship between force requirements and what is non linear?
spatial accuracy
154
as force increases, what happens to spatial accuracy?
it decreases, plateaus and then decreases again
155
schmidt's law utilizes what loop system
open loop
156
fitt's law uses what loop system
open and closed
157
what is a major limitation in the usefulness of performance curves?
they do not measure relatively permanent changes
158
Are relative measures of retention affected by temporary factors?
yes! it is dependent on where people left off at the end of practice, so it depends on instruction, tiredness, etc. it is not a pure measurement.
159
What is the name given to when the motor program is thought to be sent in the sweeping clock face/Slater-Hammel study?
Point of no return
