quiz 1 Flashcards
motor skill definition
tasks with specific goal, performed voluntarily, requiring body and/or limb movement, needs to be learned
components of a motor skill
- perceiving relevant environmental features
- deciding what to do and the timing of the action
- producing the muscular activity required to generate the movement goal
why is it important to categorize motor skils
- be able to understand research
- they are complex
how are motor skill classified
on a continuum
- discrete vs continuous
- open Vs closed
- Fine Vs Gross
discrete skill
there’s a start and end
soccer kick
basketball shot
serial movement
something that has a start and end in the middle of a movement, its a set of skills into one
gymnastic routine
play piano
continuous movement
repeative for a long time
- running
- swimming
open skills
environment unpredictable
returning a punt
catching a butterfly
wrestling
closed skills
environment predictable
bowling
brushing teeth
writing
what traits define succes in closed skills
precise and constant
planning/programming
what traits define success in open skills
perception
adaptability
fine motor skills
smaller muscle movement
gross motor skills
bigger muscles groups
what is measuring motor performance
- the ability to measure changes in motor performance is critical for evaluations and helps use understand amount of learning
consideration when measuring motor performance
- objectivity
- reliability
- validity
objectivity
likely hood that 2 individuals or 2 tools would be able to come up with the same measure of performance
- highly dependent on a tool you use to measure
reliability
interaction between the tools
validity
how well do these measurements translate to perform if we change the environment
how would you classify the skills used in motor learning and control research
discreet, closed, fine motor skills
Assessing motor performance
target and performance must be measurable values
constant error
indicates the magnitiude of error
- can be computed in more than one axis
- sign gives the direction of the error
mean constant error (CE)
the average error in the response
how consistent is their performance
it is the variability in the movement outcome about the mean value
variable error
consistency and reliability
what does variable error NOT depend on
whether the performer was close to the target
constant error is the measure of?
accuracy
variable error is a measure of?
precision
total variability
measure of overall error
Root Mean Square Error (RMSE)
- sum of the squared difference between the achieved position and the goal position
what does TE measure
consistency around the target values
Absolute error
absolute deviation between the performers movements and the target
Absolute constant error
is a transformation of constant error
- represents how far off the performer’s mean response is from the target, regardless of whether the errors are in the positive or negative direction
measuring performance in a continuous task
can compute the difference between performed trajectory and target trajectory
also the RMSE
- measuring the deviation over a sampling variable (usually time)
biomech Vs motor learning
biomech: quality of movement
motor control: error and performance
how can movement be characterized
looking at kinematics
- motion rather than forces that created motion
kinematic markers used to describe movements
- position information
- velocity information
- acceleration
why are kinematics useful
- give researcher detailed info about current performance and improvement in actions
- detailed and understandable feedback to participants
- neuronal firing patterns reflect direction and speed of upcoming actions
what parts of the brain predict kinematics of movement
- posterior partial cortex
- motor cortex
temporal characteristics -RT
was used as a proxy for cognitive function
what is RT
is a measure of the time from the arrival of a stimulus to the beginning of the response
- stimulus is unacticipated
what are some ways to control anticipation?
vary the time that stimulus is present to make it more unpredictable
present a stop and go stimulus
RT components
warning
stimulus presented –>(contains premotor RT, and motor RT) –>response begins
response ends
pre- no muscle acitivty
motor- muscle activity
temporal characteristics- movement time
is the time interval from the initiation of the response to the completion of the movement
what different processes may be studied using RT and MT
- process to initiate a movement
- processes to complete a movement
- different processes may underlie correcting a movement as well
measuring and evaluating relationships
often we are concerned with the relationship between movement characteristics and performance
what is the simple statistical way to quantify the strength of a relationship?
correlation and regression
correlations
measures both the direction and strength of a relationship
correlation coefficient (R)
R2 measures?
the shared variance (can convert to a percentage by x100)
regression
allows us to predict one variable from another
- simple regression fit a linear model to data that we have collected
what is a indirect way of measuring capability in a motor task?
measure performance on a dual cognitive task
- attention is a limited capacity resources
- the less attention a task takes, the more the performer has it mastered
RCT
- control group vs experiment groups
why use RCT in sports
examine whether training with a dual task can improve a sport-related performance
can dual task can improve a sport-related performance?
experiment group improved in all basketball-related tests compared the the control group
- no difference in ERP data suggesting very little underlying changes
human information processing
input–> processing–>output
chronometric approach was adopted
- measuring timings of the input output and get the amount of processing that must take place
The stages of human information processing
many different information processing activities take place during the RT
- one can usually infer that RT is related to the amount processing of stimulus or task
easy measure of processing
SImple reaction time
simple reaction time
a task that involves reacting to one stimulus
- give a measure of processing time
- correlated with age
- affected by: fatigue, attention, sensory modailiy of cue
the stages of information processing
stimulus (input)
stimulus identification
response slection
response programming
(SI, RS, RP is in reaction time)
movement= output
parallel processing
overlapping processes
- 2 or more stages occuring at once
serial processing
processing in sequential steps
human information processing serial Vs Parallel
some steps can occur in paraelle under certain conditions
some steps must occur in sequence in certain conditions
stimulus identification
person must perceive the stimulus
- involve detection and identification
the stimulus must be sensed and processed
- processed until it contacts memory
sensation
involves the activation of sensory receptors
- have a minimum amount of stimulation required to detect
- can be affected by attention at both the behavioral and neural level
perception
involves interpreting those sensation
- involves the combination and integration of numerous sources of information to form a percept
what is stimulus detection affected by
stimulus clarity, and intensity
response selection
after the stimulus is detected, the actor must now decide what response to initiate
- can explain relationship bwtween the RT and # of possible stimulus-response alternative
choice RT
a RT task wherein the participant is presented with more than one possible stimulus and the required response if dependent on that stimulus
Hicks law
- the time it takes to make a response is related to the # of stimulus response alternative
- choice RT increases nearly a constant amount (150ms) when S-R alternative are doubled
- log-linear relationship
bits of information
log2(N)= a bit of information
- the amount of information required to reduce uncertainty by half
- least amount of binary decisions
Bit = Binary Digit
interpreting Hick laws
choice RT = a + b(log2(N))
simple RT
reacting to 1 stimulus with the same response
- response programming (RP)
GO/NO go tasks
reacting to one stimulus, and not reacting to the other
- Stimulus identification (SI), response programming (RP)
choice RT
selecting the appropriate response for a given stimulus
- SI , RS, RP
what is the fastest?
simple RT
what is the slowest
choice RT
donders subtractive method
crossing out RI, RS, RP to get the answer of either of those parts of RT
other factors affecting response selection
feature of the S-R relationship could impact
- s-R compatibility the mapping of the response to the action
simon effect
irrelevant spatial features have effects on RT
- participants responsed to auditiory cues played in either left or right ear
had to press the right key when they hear the word right
and press the left key when they hear left
- compared responses of spatially compatible trials vc incompatible trials
the joint-Simon effect
when 2 people perform the Simon task, they perform siliar to when preforming a2 choice task
response programming
is the transformation/translation of the active concept into the muscular actions that will achieve the goal
- sensorimotor transformation
- events occurring in response programming could be related to memory
- involves the preparation of relevant motor structures
movement complexities
accuracy requirement- the size of the goal
- speed-accuracy tradeoffs (Fitts law)
movement component
- the number of ‘parts’ of a movement can increase the initial programming time
- time between components is important
does movement complexity affect RT
it does but movement complexity also affect RT even before the selection has been made
what happens when the choice of movement is unknown
more complex S-R relationships take longer to programs
programming trajectory
- proponents of sensory-coding theories of motor behaviour argue that we plan a point-to-point visual trajectory
- based on the idea that neural activation patterns in motor areas represent spatial goals in a visual reference frame
criticisms of sensory coding and reference frams
- behavioral relevance is questionable and has been criticized
- how do we make movements to non-visual targets
- cannot thoroughly explain rapid corrections based on information from non-visual sensory sources
motor program
a prestructured set of movement commands that defines the essential details of a skilled action with minimal (or no) involvement of sensory feedback
what does the motor program do during response program
achieve the action specified
criticism of motor programs
storage problem
degrees of freedom
storage problem
imagine if every movement was distinct motor program- it would require much more space to store them all
degrees of freedom problem
there are too many degrees of freedom to control (to many moving parts)
dynamical systems theory
stereotypes similarities of movement patterns are not represented in motor progams but emerge naturally due to complex mechanics
what does the dynamical systems theory solve
the DoF problem
where does motor program oringinate from?
more cognitive psychology
where does dynamical systems originate from
engineering, biomech, rehabilitation
what is response programming related to
the preparation of the motor program
can responses be preparaed in advance?
yes
anticipation how can it be reduced
multiple stimuli
have time more bigger
anticiaption
in information processing- anticipation means the removal/ reduction of the response selection stage
what are the types of anticipation
temporal anticipation
spatial anticipation
temporal anticipation
when anticipation
spatial anticipation
what anticipation and where
precuing technique
was found that precuing any of the variables (arm, extent, direction) led to a decrease in RT
how can anticipation be studied
- examining the startle response
- a startling tone has been shown to trigger a prepared movement at short latency
- startle is thought to act as a subcortical trigger for prepared movements
sensation
afferent- info coming in
- involves the activation of sensory receptors
- specialized sensory organs are activated by a stimulus
- organs decode sensory information transforming it into neural signals
perception
is the interpretation of those sensory signals
- involves the combination and integration of sensory (afferent) information from multiple sources
other important senses
sense of balacne (equilibrioception)-
sense of body position (propriception)
sense of temperature (thermoception)
pain sense (nociception)
what is sensory information used in
both movement planning/programming (feedforward) and movement control (feedback)
the use of sensory feedback to modify motor commands is referred to as
closed-loop control
closed-loop control
- system receives instruction (input)
- the goal is define (reference mechanism)
- executive level relays instructions to achieve the goal
- effector level enacts the instructions that are relayed (produces an output)
- sensors in the environment produce feedback
examples of a closed loop control system
thermostat
- electric kettle
- cruise control
visual system- receptors
begins at the eye
- light from an object in the visual field is refracted and focused onto the retina
photoreceptors
light sensitive cells line the back of the retina
2 main types: rods and cones
- different structures and response profiles
- different types of visual information
- rods (motion/detection)
- cones (fine detail)
visual system- central processes
- visual info travels through the optic nerve, and various subcortical structures to the lateral geniculate nucleus (LGN)
- from LGn in thalamus, is relayed to the primary visual cortex
primary visual cortex
is where visual features such as stimulus direction, stimulus speed, and object orientation
visual streams
dorsal stream
ventral stream
dorsal stream
where visual information travels to the parietal areas
- known as the vision for action stream
- inputs from the full visual field
ventral stream
where visual information travels to the temporal lobe
- known as the vision for perception stream
- inputs from the LGN mainly from central vision
evidence for the dorsal and ventral streams
- perception scales to illusions, however grip aperture does not
- grip aperture is a measure of the distance between index and thumb when performing reaching movements
- no relationship between constant error and tail-orientation in muller-lyer illusion
vision
does not have an effect on balance
- visual systems indicates where your hand and eyes are in space
optic flow
when we move our head, the angle the light rays hit the retina change
- the environment flows past us as our head and body move
- gives us crucial info about our position and position of objects
the rate of change
the rate of change of the size of an object on the retina can indicate whether the object is coming toward you or going away from yu
what can you use the rate of change for?
estimate the time of contact (Tau)
time to contact
is directly proportional to the:
- size of the image divided by the rate of change of the image
proprioception
sensory information about the position of the body in space
includes:
- vestibular system
- sensory organs in the muscles and joints
- cutaneous receptors
the vestibular system
- located in inner ears
- otolith organs provide information about the orientation of the head with respects to gravity (utricle and saccule) - linear accelerations
semicular canals- are three fluid filled half circules
- in position sense directoin
- can sense rotation
- thick fluid in the canals displace hair cells (mechoreceptors)
what is the vestibular system important for?
balance and orientation
vestibular-vision interactions
when we move our heads- our eyes stable due to vestibualr-ocular refelxes
- we move our head one way eyes move the other way
- alternating slow and fast movements are called nystagmus
- will stop if head keeps rotating
muscles spindles
provides info about muscle stretch
- located in fleshy muscle body
- oriented in line iwth the muscle fibre
- comprised of intrafusal muscle fibers
- spindle also connects to alpha motor neurons of the muscle
stretch reflex
specialized sensory receptors called muscle spindles within the muscle detect the change in muscle length and the rate of stretching.
golgi tendon organs
- located at the muscle tendon junction
- highly sensitive to active muscle tension
- each one is attached in series to small groups of muscle fibres
- hypothesized to contribute less to overall position sense than muscle spindles
joint receptors
- embedded in the joint capsule (areas that are stretched the most)
- neural signals are strongest at the end ranges of the joint movement
- less involved in position sense than muscle spindles
how important is proprioception
- plays a role in rapid-feedback based responses
- some say is used to plan distances and vision to plan direction
- some say that its suggest proprioception may be the key feedback based mechanisms
- both the speed of processing and reflex circuity make is possible
where is proprioception processed
in the primary somatosensory cortex
dorsal stream processes mainly ____ related visual information
action
ventral stream processes for mainly _____ related visual information
perception
golgi tendon organs sense muscle ____?
tension
muscle spindles sense muscle _____
stretch
what are issues with motor programming theory
- storage
- degress of freedom problem
- novelty problem
novelty problem
how do we learn new action if each new action requires a pre-determined program
open loop
there is an executive level and an effector level
- the executive sends the motor program to the effectors, and the effector carriers out the instructions without modification based on feedback
open loop control
- are not less complex than closed
- doesn’t make corrections based on feedback
- a oven doesn’t stop when food is burning
- pointing without vision there are other senses that can tell you information
what do we use sensroy information for
feedforward control
feedforward control
involves a signal that
- readies the system for the motor command
- readies the system for some input
how do we know which one is occuring?
- concept of “reafference” or corollary discharge
- a copy of the motor command that was sent to muscle is delivered to sensory regions in the brain
what is the copy of the motor command known as
the efference copy
efference copy in limb movements
the efference copy allows for the prediction of the action outcome and the sensory consequences of the action
- tells the sensory system what was ordered by the motor system
- uses the predicted and actual sensory feedback to compute an error
how can we test for the existence of feedforward control in limb movements?
using active vs passive task
error detection and efference
can use active vs passive tasks
- ppl have better at error estimate when they have efferent information
- proprioception**
- they are able to predict the outcome of their actions (when effernt info is good)
forward models
used to establish predictions about the desired state
- produce predictions
- establishes a reference of correctness for which to compare to based on sensory info
- used to update the reference of correctness
how are those problems with motor programming solved
computational solution
- motor programs must be generalized
the generalized motor program
relative timing
relative force
sequence of events
- these are in the function, they are not changes by the user
relative timing
the timing of muscle activation relative to others
relative force
the force of muscle activations relative to others
sequence of events
the sequence of events
open loops processes occur in the ____ of sensory feedback
absence
a system is open loop when it ________________
does not take feedback into account
the efference copy is a copy of the motor command that allows for prediction of the ____ and the _______
action
sensory consequences of the outcome
GMPs accept certain parameters
- overall duration of the action
- overall force of the action
- effector used for the action
what does the inclusion of the effector parameter indicates that?
the muscle for a particulaar action could not be stored in a GMP
when are the specific joints and muscle added to the command
during the preparation of the program
- supported by bilateral-transfer
relationship between speed and accuracy
when examining voluntary, goal-directed movement, there is a relationships
fast movements are less accurate
accurate movement and slower
what has the speed and accuracy been described by
for feedback movements (closed loops) has been mathematically described by paul fitts
Fitts law
- tap between 2 targets as rapidly as possible maintaing 95% accuracy
- movement time
- movement amplitude (A)
- target width (W)
fitts paradigm
index of difficulty (ID)= log2[amplitude)/(width)]
- ID increase = Increase movement time (MT)
generality of Fitts law
holds for:
- children
- lower limb movements
- under magnification
- imagined movement
- perceived movements
breaking fitts law violatoin
fitts law may not hold in all contexts
- violation of the law was found when contextual target cues were present
do we plan for the worse case scenario?
we don’t, we adapt efficiently
what causes speed accuracy tradeoffs
impulse-variability theory
impulse-variability theory
- the variability in the duration of a group of contractions is related to the mean duration
- the variability in force produced increases as a function of the force produced
variability increases to about 65% but then decrease at higher levels of force output
- movements should become more accurate when more than 65% of force is required
movement time in a reciprocal movement is linearly related to?
amplitude of movement
width of object
a process
is a set of events or occurrences that lead to a product or state of change
- we are interested in processes associated with retrieving a motor program from memory
largely assimed
practice
the purposeful repetition of a skill or behaviour
- practice makes permanent
experiences
the fact or state of having been affected by or gained knowledge through direct observation or participation (merriam- wedster)
motor learing ins relatively permanent
change of state is not readily reversible
- any changes that is readily reversible is not attributable to learning
learning produces a capability for skilled movement
product of learning: the ability to move skillfully in a particular situation
what is the goal of motor learning
is the strengthen the quality of the internal state such that the capability of the skill will be altered in future attempts
capability for movement
- stresses the role of the internal state that leads to the skilled behaviour
- motivation, physiological states, fatigue
- numerous factors can affect the movement outcome, but have little impact on internal states
learning is not directly observable
we often have to infer these changes based on behaviour
- we measure and test the stability of learned behaviours
learning involves highly complex phenomena
- many processes and many possible explanations
- multi-system interactions
neural basis of learning
- many different types of learning, difficult to examine
- implicit vs explicit
- once you leaned you have permanently changes
- difficult to asses if changes in neural and physiological activity is correlated with learning or changes in behaviour
neural basis of learning- theories
Donald Hebb’s
neural networks (Geoffrey Hinton)
activation in networks can be observed by looking
donald hebbs
- neurons that fire together, wire together
neural networks
most neurons recieve inputs from other neurons
- these inputs are weighted
- neurons can adapt their weights
activation in networks can be observed by looking at
output: electrical activity
energy consumption- bloodflow
functional connectivity analysis
examine the time-series of FMRI data in different brain regions
- correlate the time-series between different regions of interest (ROIs)
- examine the strength of those relationships
functional connectivity and motor learning
- some studies shown that functional connectivity can predict motor learning
functional connectivity and motor learning
- some studies have shown the functional connectivity can predict motor learning
McGregor and Gribble 2017
- measured participants connectivity prior to observational learning protocol
- found that participants who had higher level of connectivity in sensorimotor regions performed better in learning paradigm
adaptation
the iterative process of adjusting ones movement to new demands
motor adaption
the trial to trial modification based on error feedback
- movement retains identity but one of the parameters are changed
- change occurs with repetition or practice and is gradual over min
- the person must de-adapt after behaviour
prism adaptation
involve performing reaches to visual target then
measuring motor leanrning
participant is exposed to a task (acquistion)
- performance on the taks is plotted as a function of trial (examines consistency)
performance curves
- linear curve
- negatively accelerated curve
- positively accelerated curve
- sigmoid “s” curve
factors affecting performance
between participants variability
- curves usually curve to rep group data (people get washed out)
within-person variability
- performance of the individual person varies trial to trial
ceiling effect: limits at the top scale
floor effects: limits at the bottom of the scale
ceiling and floor effects
gymnastics: eaeir to improve your score at mid-level
reducing a score in golf is easier when strokes are high
changes in performance levels becomes insensitive to change in learning
performance curve considerations
how acquisition is measured can affect the interpretation of performance curve
retentiono tests
testing participant on the same task after a time interval
- 24h retention interval is often used (for both retention and transfer)
- longer retention interval, the more transient effects are reduced
transfer tests:
involve a new variations of the practiced task
- can involve the tasks with a twist (new speed or conditions)
- can involve a task that has not been practiced before
henery and rogers 1960 findings
RT increased as movement complexity increases
- concluded that the programming of more complex movement requires more time
roberts el all 2017
- replicated the gunslinger effect showing shorter time to peak acc for reacted movements
roberts el all 2017 results
target influenced distance travelled to peak deceleration- indicationg an influence later in the movement trajectory
roberts el all 2017 results suggestions
- the ventral stream may be used more for limb target control and the dorsal stream used more for planning
