Section 2 Notes Flashcards
What are the 2 categories of performance measures?
- give some examples
- performance outcome measures (movement components); examples: time to complete task (running a mile), distance (height of jump), % of errors (free throws)
- performance production measures (motor skills); examples: velocity (speed of limb during action), joint angle (angle of each joint of arm at impact of hitting ball), displacement (distance the limb traveled when performing action)
3 common ways of assessing movement
- movement error (or accuracy)
- movement magnitude (distance, muscle amplitude, etc)
- movement time or speed (velocity)
Explain constant error (CE) as a measure of movement error. What is the problem with it? Give the formula
- provides amount and direction of deviation from target
- primarily used for discrete skills
- problem: doesn’t consider amount of scatter or variability of error
- see notes for formula
Explain variable error (VE) as a measure of movement error. Give the formula
- measures the inconsistency or variability in the movement outcome (basically the standard deviation of CE)
- primarily used for discrete skills
- see notes for formula
Explain root-mean-square-error (RMSE) as a measure of movement error. What is the problem with it? Give the formula
- measure of overall error. Gives an indication of the amount of spread of the movement across the duration of the trial/performance. used more for continuous skills (like pursuit tracking)
- see notes for formula
Explain root-mean-square (RMS) as a measure of movement magnitude. Why would you use it? Give the formula.
- quantifies the magnitude of a signal or a set of data (e.g., displacement across time)
- If you took the average of a sine wave oscillating around zero, the value would be zero regardless of the amplitude of the wave. RMS is one of several ways to get a sense of magnitude when an average might be misleading.
What are the reaction time paradigms?
- movement time and speed
Define: reaction time (RT)
time between the onset of a stimulus and onset of a response
- do not confuse with response time
- onset of response (and therefore reaction time) can be based on movement or some other variable such as onset of muscle activity (which is premotor RT)
Define: simple-RT tasks
only one response choice available
Define: choice-RT tasks
multiple response choices are available and/or multiple stimuli may be
presented
Define: movement time (MT)
interval between the initiation of the response to the completion of the movement
Define: response time
is the sum of the RT and MT (note: don’t abbreviate response time with RT, otherwise someone, including the exam marker, might think you mean reaction time)
Define: premotor RT
time for central processing (e.g., perception of stimulus, decision making)
Define: motor RT
delay period between muscle activity onset and measurable movement of the body
Explain the use of: force plates
used to measure kinetic data (i.e., forces that cause movement)
- determine how fast and hard a person loads a surface
- can be used to measure COP (location of vertical ground force reaction vector which is the weighted average of the location of all downward forces acting on the force plate)
- COP can act as a measure of postural sway as well
Explain the use of: motion capture cameras, goniometers, accelerometers, inertial measurement unit (IMU)
- used to quantify kinematic data (e.g., during walking or reaching movements)
- Camera system used to record kinematic data. Kinematic data describes movement, independent of forces that cause the movement. It includes linear and angular displacements, velocities, and accelerations.
- goniometer: measures joint angles
- accelerometer: measure body and/or limb acceleration
- IMU: measures force, acceleration, and orientation using accelerometers, gyroscopes, and magnetometers to track a person’s movement
Explain the use of: electromyography (EMG)
used to record electrical activity from muscles
- indwelling electrodes (electrodes inserted into individual muscles) and surface electrodes (electrodes placed on skin)
Explain the use of: eye tracking
head-mounted mobile systems used to monitor eye movements
Explain the use of: neuroimaging, neurostimulation, and neural recording equipment
used to study nervous
system activity and function (related to movement)
Define: posturography and computerized dynamic posturography (CDP)
- assessment of standing balance usually using a force plate
- CDP: mechanized platform with an embedded force plate and a visual surround. It can be used to administer the sensory organization test (SOT)
Define: sensory organization test (SOT)
In this test, the support surface and/or visual surround can move. The manipulations across the six conditions create different conflicts between sensory information. For instance, visual information tells the brain you are not moving but vestibular information says you are moving.
Define: microneurography
technique to record electrical activity of single axons within a nerve (example: to determine activity of an individual sensory receptor)
- A very thin microelectrode is passed through the skin, into the nerve, and then into one of any number of nerve fascicles. Within a fascicle, small adjustments are made, placing the electrode tip next to 1 or more axon sheath(s).
What 2 improvements lead to the ability to measure and record the activity of single neurons in the 1920s? These improvements also allowed for the first studies of 2 fields. list them
- improvements in the ability to amplify very small electrical signals
- making of smaller electrodes
- receptive fields and tuning curves
Fill in the blank: Single neuron recording requires an electrode in the brain within _______ of neurons as well as cell sorting
50-150 μm
