lec 11-12 Flashcards
Typically, what happens to accuracy when speed increases
decreases
what happens to accuracy when speed decreases
accuracy increases
What relationship does Fitt’s Law discuss?
the relationship between movement time, amplitude and target width
What law is related to the logarithmic speed accruacy trade off
fitt’s law
what law is utilized by computer-person interactions? Like keyboards?
Fitt’s Law
“The larger and closer an object is, the easier it is to reach” corresponds to which law
Fitt’s law
Describe Fitt’s task
This task involved tapping back and forth between two targets, and how the duration of movement time increases along with space between targets
what is the equation for index of difficulty
log_2(2A/w)
What graphing equation is involved in Fitt’s law
MT = a+b(log_2(2A /W)
What happens to the index of difficulty if A increases?
ID increases
If index of difficulty were to increase, what does that mean for its components
A must increase, or W must decrease.
what happens to MT if ID increases
MT increases
What is “a” in fitt’s law equation
a = y intercept when ID = 0
practice solving for ID
what do you have to do to solve for ID?
ask yourself what x raised to the power of 2 = 2a/w
what happens to MT as accuracy constraints (ID) increase?
MT increases
what is Schmidt’s Law
Schmidt’s law: linear speed accuracy tradeoff
what does fitt’s law generalize to?
discrete aiming movements
for fast discrete movements, what law do we use?
schmidt’s law
what is fitts law
logarithmic speed accuracy tradeoff
what processing loop is involved with schmidt’s law
open loop, since it is rapid, programmed movements with little to no feedback
how quick are the movements in schmidt’s law in ms?
under 300 ms
what factors change the MT in schmidt’s law
accuracy and movement distance
what does an increase in speed do to accuracy and variability in a schmidt’s law task
decreases accuracy/increased variability
what does w_e mean?
w_e: effective target width = standard deviation in movement endpoint
What variable in the speed accuracy trade off do we look at to find accuracy?
w_e
if a task is easy, what do we expect for the spread of scores/errors?
slower MT, less amplitude, smaller spread/error
what is the formula for effective target width in schmidt’s law
w_e = a+b(A/MT)
when we vary MT and amplitude, we see a _______ relationship with accuracy/speed
linear
according to Fitt’s Law, which of the following changes would result in an increased index of difficulty for the Fitt’s tapping task?: increased MT, increased target distance, increased target width
increased target distance will increase the index of difficulty
Fitt’s law describes the relationships between which of the following variables: distance between two targets, bits of information, width of target, MT and RT
distance between targets, target width, and movement time.
What is effective target width measuring?
the standard deviation of a participants end points in a rapid discrete aiming task
What variables are manipulated in Fitt’s Law?
target amplitude and target width
what variables are measured in fitt’s law
movement time
what variables are manipulated in schmidt’s law
target amplitude and movement time
what variables are measured in schmidt’s law
effective target width
which law corresponds to linear tradeoff between speed and accuracy
schmidt’s law
which law corresponds with a logarithmic tradeoff between speed and accuracy
fitt’s law
With increased precision demands, what sensory feedback becomes more important?
vision
In Fitt’s law, there is a greater proportion of MT occuring after _____
peak velocity
in linear speed accuracy tradeoff, there is ______ time before and after ________
equal; peak velocity
As force increases, what happens to the force variability?
increases
What percentage of maximum force results is associated with a peak in force variability
~70%
define primary force
primary force: open loop, initial ballistic programmed impulse, intentionally short
define corrective sub movements
corrective sub movements: small, fine tuning movements that follow the initial action
define motor learning
motor learning: a set of processes associated with practice or experience leading to relatively permanent changes in the capability for skilled performance
what are the characteristics of motor learning
- set of processes
- Produces an acquired capability for skilled movement
- Results from practice/experience
- Not directly observable (must be inferred)
- Relatively permanent (rules out changes due to temporary performance factors)
Describe the difference between performance and learning
we can infer learning from performance, but performance is not learning.
What testing can be done to see if something has been learned
- retention testing
- transfer testing
After a bout of practice/performance, what do we have to do before immediately inferring if there is motor learning
wait! We have to allow at least 24 hours for the temporary effects to lessen
Performance is a measure of ____, and learning is a measure of ______
now; later
what measure, performance or learning, is associated with a single practice?
performance
what measure, performance or learning, is associated with several sessions/long term
learning
What is the design of retention tests?
- pre test
- acquisition period (diff groups, diff practice types)
- no practice interval (24+ hours)
- retention and transfer test
define temporary effects
temporary effect: effects that have short term affects on performance but vanish with time
What are some of the factors of temporary effects? What might be responsible for it?
motivation, fatigue, mood, attention, instruction, weather etc
how can we quantify performance?
performance curves
how do we capture/visualize skill acquisition
We measure performance across practice, using trials and blocks, which allows us to make conclusions about temporary performance and infer learning!
Are negatively accelerated performance curves common or rare?
very common!
Define negatively accelerated performance curve
negatively accelerated performance curve: rapid initial improvements followed by decreasing gains
what happens to skill over time? What is the shape of a performance curve?
Over time, skill learning slows down. the shape of the performance curve typically is sigmoidal, plateauing at the top check that performance curve and learning curve are the same
define positively accelerated performance curve
positively accelerated curve: a performance curve associated with little improvement, and then rapid changes
which is more common: negatively accelerated performance curve or positively accelerated performance curve?
negatively accelerated performance curve - where there is a sharp incline and then slow in skill learning
which type of performance curve do we observe for balance tasks
positively accelerated performance curve
what are the factors in interpreting a performance curve
- between person variability
- within person variability
- scoring sensitivity
- ceiling and floor effects
how does between person variability change our interpretation of performance curves?
When group data is shown, we can deduce general observations, but the averages might hide individual differences in performance
describe how within person variability changes our interpretation of performance curves
The average performance of an individual across a block can hide trial to trial variation in performance
what is the difference between trials and blocks
trials are single bouts, blocks are a series of trials
how does scoring sensitivity change our interpretation of a performance curve
The sensitivity of scoring can change our conclusion - either with poor performance but high improvement or great performance and low improvement.
define scoring sensitivity
scoring sensitivity: refers to how sensitive the measure is to changes in performance
what is meant by a stringent scoring sensitivity
stringent scoring sensitivity is a measure that is mostly yes/no, wrong/correct, miss/hit. there is little room for error, and typically a smaller bandwidth i think
what is meant by less stringent scoring system
less stringent scoring systems are more relaxed, and typically have subcategories instead of only two for a miss/hit. they typically have larger bandwidths
what kind of scoring sensitivity is associated with a larger bandwidth
less stringent scoring sensitivity
what kind of scoring sensitivity is correlated with a small bandwidth
stringent scoring sensitivity
what % is a small bandwidth
5%
what % is a medium bandwidth
15%
what % is a relaxed or large bandwidth
30%
what are the percentages for a small, medium or large bandwidth
5%, 15%, 30%
what kind of bandwidth is sensitive to variation
small bandwidth
what kind of bandwidth is not sensitive to variation
large bandwidth
How do ceiling and floor effects change our interpretation of the performance curve
ceiling and floor effects give us information about a tasks’ difficulty. If either of these are approached, changes in performance might become increasingly insensitive to internal changes in learning. we want to avoid either of these.
define ceiling effect
ceiling effect: limitations at the top of the scale
which performance curve effect is insensitive to further improvements
ceiling effect
define floor effect
floor effect: limitations at the bottom of the scale
which performance curve effect is insensitive to further improvements
both the floor and ceiling effect
which is better, ceiling or floor effect?
neither. both are to be avoided, as ceiling indicates a task is too easy and floor effect indicates a task is too difficult
What does the ceiling effect tell us about a task
that it is too easy
what does the floor effect tell us about the difficulty of a task
it is too hard
what are the methods for measuring learning
- retention
- transfer
what is the absolute retention method
absolute retention method: a pure measurement of learning that examines performance attainment after a break
what method of measuring learning is best for comparing across groups after an intervention
absolute retention
what is the relative retention method
relative retention: a measure of what has been forgotten over a retention interval, relative to prior practice performance.
which method of measuring learning is not pure, and impacted by temporary effects?
relative retention
when looking at a graph, how do we determine what the relative retention of something is?
we look at the difference between performance at the end of acquisition/practice, and the start of the retention phase
when looking at a graph, how do we determine what the absolute retention of something is?
we look at the performance point that post learning STARTS at
define memory consolidation
memory consolidation: the neurological process of retention
Memory consolidation occurs at the _____ and _____ level/region
cellular; system level brain
What about performance effects memory consoldiation
- how hard we practice
- the type of task
- etc.
How does post practice/performance effect memory consolidation
- how much we had
- how much sleep or practice we had
define skill retention
skill retention: the ability to maintain a learned skill
are some tasks more resistant than others to forgetting? why?
yes - I think because it all depends on how often you do the task, for how long and how hard you try at it. these are all things that affect memory consolidation, so it makes them easier to remember
learning is a set of ______ processes that must be inferred through measurement over time
unobservable
which factor of a performance curve is not sensitive to differences (among people?)
ceiling and floor effects
which of the two retention measures takes into account performance IN practice?
relative retention apparently
