[Hans Blom, 970424h]
Some quotes from:
R.W. Watson, R.D. Jones, N.B. Sharman: Two-dimensional tracking tasks
for quantification of sensory-motor dysfunction and their application
to Parkinson's disease. Medical & Biological Engineering & Computing,
March 1997, pp. 141-145.
Tracking tasks have been extensively used since the Second World War
to provide quantitative information on the performance of the human
sensory-motor system, and to determine how the system functions in
both its normal and diseased states.
Although all of the tests in the original test battery were of a 1-D
nature, it was considered that measurement of sensory-motor function
in a 2-D environment might provide additional valuable information on
certain sensory-motor disorders. ... 2-D tasks are likely to stress
the sensory-motor system to a greater extent than 1-D tasks ... and
are thus likely to be more _sensitive_ in terms of allowing subtle
differences in sensory-motor function to be detected.
2-D random [the spot to be tracked moves continuously] and step [the
spot moves in large steps] pursuit tracking tests ... high resolution
colour monitor ... floor-mounted joystick or the computer's mouse ...
the subject's response is sampled at 30 Hz ... or 60 Hz ...
... reaction time ... rise time ... overshoot ... target entry time
[time it takes to manipulate the cross on the screen to be fully
within a target box] ... overall [integrated] error
Parkinsonian subjects cannot track a random signal as accurately as
normal subjects. ... There was no significant difference between the
gains for the two groups. ... reaction times ... target entry times
... and overall errors ... were all greater than those for the normal
group. ... The majority of step response graphs for the Parkinsonian
group exhibited the classic Parkinsonian step response of a stepped
approximation to an overdamped response
... both the normal and Parkinsonian subjects were able to use the
spatial predictability of the central target to improve their
tracking performance. This resulted in both groups showing reduced
errors ... reaction times ... and target entry times ... There was no
change in rise times.
2-D tracking performance of the Parkinsonian subjects was inferior to
their 1-D performance [unlike in the normal subjects]
... males have a slight overall performance superiority over females
on tracking tasks ... females have a lower maximum speed/acceleration
... this is the first study to show that Parkinsonian subjects are
_unimpaired_ in their ability to benefit from advance spatial
information on a step task.
Greetings,
Hans