LAB Content for MT2 Flashcards
What is a Motor Program?
a pre-structured set of neural commands, organized in advance, that allow the entire movement sequence to be carried out
What is One line of evidence for the existence of motor programs?
The “point of no return”
- This is when the internal “go” signal is issued and the motor commands are released and can no longer be inhibited
When does the Point of No Return Occur
The release of the motor commands (“point of no return”) was determined by the:
point at which the probability of inhibition is 50%
Slater-Hammel (1960) Task & Data
What is the point of no return?
- Point when the timer stops
- Point when the movement is completed
- Point when the movement is prepared
- Point when muscle commands (mtr prgrm) are sent
- Point when an error is made
Point when muscle commands
(motor program) are sent
Good, yes, it’s the point when muscle commands (motor program) are thought to be sent from the cortex to the effectors and can no longer be retrieved or inhibited.
When did the point-of-no-return (PONR) occur based on the sample graph in the excel sheet/ and last page of the ppt?
Select the closest estimate from the selection of possible answers.
~50 ms
~240 ms
~215 ms
~80 ms
~320 ms
~215 ms
Good, it’s an estimate somewhere between 160ms and 240ms (we know there’s 80 ms between points, so the next point would be 200ms and the 50% prob. Occurs just after the 200 ms (before the target) mark.
Which measure/value in the raw data excel sheet “Anticipation Raw Data” for the sample data (in top 3 rows, first 2 columns), gives information about tendency to respond too early (negative) or too late (positive) in general AND based on the numerical value, what is the tendency based on the sample data?
<think about how this compares to your data too. What would be an advantageous strategy in this task where the sweeper sometimes stops, would it be to respond early or perhaps wait and be a bit slower?>
- Mean AE, tendency to respond too early
- Mean CE, tendency to respond too early
- VE, tendency to respond too early
- Mean AE, tendency to respond too late
- Mean CE, tendency to respond too late
- Mean CE, tendency to respond too late
Good, most data will have a positive number for CE, as this means they responded late on average, indicative of using a strategy of waiting as long as possible to respond just in case the timer stopped.
At 80 ms before the arrow (interception point), I should be able to inhibit responding all the time. True or False
False
Yes, good. You should not be able to inhibit this close to the interception point. At the other end, 320 ms before the interception point you should be able to inhibit.
What is Fitts’ Law?
Fitts found that movement time (MT) increases proportionally as the index of difficulty (ID) of the movement increased
Fitts’ Law outlines a linear relationship between MT and ID, whereby “a” represents the y-intercept and “b” represents the slope of the line
True or False
The y-intercept in the Fitts’ Law equation (the “a” parameter) represents the rate of movement processing and what happens to MT as Index of difficulty increases by 1.
False
Good, the rate of processing refers to the slope, intercept represents accuracy for low accuracy conditions (tapping on the spot, where targets overlap)
Determine the ID for a movement with an amplitude of 64 cm and a target width of 2 cm.
6
Using the sample graph (or the sample data/equation), what would be your closest estimate of the expected MT for an ID of 2.5?
800 ms
Using the equation from the sample graph, or activity lab;
MT = 315+ 200[log2(2A/W)], what would be the expected movement time (in ms) for an ID of 5? Please give a number answer only (no units).
HINT: Check the graph too to make sure the number you calculated makes sense given other values.
1,315
