reaction-time data

[Paul von Hippel -- Ohio State <pvh@xxxxxxxxxxxxxxxxxx>]

I'm analyzing the results of an experiment in which listeners heard
melodic fragments. After each fragment, they indicated (by typing)
whether they thought the melody was more likely to continue upward
(press "u") or downward (press "d"). The computer recorded boht their
response and their response time.

The response time data is really interesting. Many of the subjects
grew faster and less variable as the experiment progressed -- of
course, I expected that. What I didn't expect was that the response
times for several subjects exhibited dependence between successive
trials. For example, a couple of subjects tended to alternate short
and long response times: for one trial they'd respond quickly,
and for the next they'd respond slowly.

I'm guessing that I've stumbled upon some effect that's well known in
psychometrics. Have you ever heard of this kind of thing? Is there a book
or article I should read on the common properties of reaction-time data?
Or is there a psychometrics newsgroup that I should be posting this note
to?


Thanks for any pointers you can offer,
Paul von Hippel
Post-Doctoral Fellow
School of Music
Ohio State University
1866 College Road
Columbus, OH 43210
614 292-7321

von-hippel.1@ohio-state.edu
(You can also reach me by simply replying to this message.
All my mail is forwarded to the same final destination.)

http://music-cog.ohio-state.edu/~pvh