Lec 10 - Speed, Accuracy & Coordination Pt.1 Flashcards
What is the speed-accuracy trade-off?
The inverse relationship between speed and accuracy in movement. Faster movements generally result in less accuracy.
What does Fitts’ Law describe?
It describes how movement time (MT) is related to the size and distance of a target. As the index of difficulty (ID) increases, movement time also increases.
What are the key variables in Fitts’ Law?
Amplitude (A) - distance between targets, and Width (W) - size of target. The index of difficulty (ID) is calculated as Log2(2A/W).
What characterizes open-loop movements?
They are rapid, discrete movements where there is little or no time for feedback. They work best for fast, pre-planned tasks in stable, predictable environments.
Name three sources of error in very rapid movements.
1) Neuromuscular noise,
2) Timing errors, and
3) Force variability.
What is synaptic noise in motor control?
Minor errors introduced at each synaptic connection due to the variability of neurotransmitter release.
How does force affect movement variability?
Higher force (up to ~70% max) introduces more variability, as increased force results in less control over movement precision.
What happens to spatial accuracy in very high force movements (70-100% of max force)?
Movements become less variable and spatial accuracy increases as force approaches maximum.
How can faster movements affect timing accuracy?
Faster movements can improve timing accuracy because less time is available for variability to affect the outcome.
How does the speed-accuracy trade-off apply to baseball batting?
Increasing swing speed can provide additional decision time, improving both timing and spatial accuracy. For example, an additional 20 ms of visual information provides about 3 feet more of ball trajectory for predictive adjustments.
