Terry Bahill
Systems and Industrial Engineering
University of Arizona
Tucson, AZ 85721-0020
terry@sie.arizona.edu
http://www.sie.arizona.edu/sysengr/slides/eyeOnBall.ppt
© 1998-2005 Bahill
Every human motor control system has a time delay of about 200
milliseconds (msec). To see the effects of this time delay hold
a crisp one-dollar bill between someone's out-stretched finger
and thumb. Tell them they can have the dollar, if they can catch
it: then drop it. The 200 msec time delay will prevent them from
grasping the bill. The human eye tracking system has a similar
time delay. But humans can overcome this time delay and track
predictable targets with no latency, provided the target position
waveform is smooth, is predictable, has a frequency between 0.1
and 1.0 Hz, and has small accelerations. We show the time course
for learning this zero-latency tracking.
To broaden our research results, we studied humans performing
real world tasks; we studied baseball players. We found that they
cannot follow the ball all the way to the plate. They cannot track
it closer than five feet from the plate. Their amazing success
in hitting the ball is due to their great powers of prediction.
References [29, 31, 33, 35, and 45]. I can adapt this lecture
to make it suitable for engineers, physiologists, neurologists
or even the general public. It requires PowerPoint and a computer
projector. This talk takes one hour.