E-prime not recording all responses

[jlozito at email.unc.edu]

Hi all:
I am currently using E-prime to make a program that presents two tasks 
at the same time. I have finished making the program, and it presents 
the two tasks perfectly fine, just as I want them to. This part has 
also worked in three other versions. The problem is that, unlike the 
other versions, this program is designed to record different responses 
for each task at the same time. The first task requires participants to 
give a verbal response and is recorded by the voice key, and the second 
task requires participants to give button presses on the computer 
keyboard. Participants are presented with both tasks at the same time 
and respond to both tasks at roughly the same time. On most trials, the 
program seems to be recording both responses. However, this is not 
always the case. On some trials (sometimes as many as 1/3 of all 
trials), the voice key is not recording any response at all. I can't 
for the life of me figure out why it isn't.

Here's a quick runthrough of how the program is set up: first, a 
stimulus is presented for a duration of 0 ms, with the length set up at 
2500 ms. The other stimulus is presented with a duration of 2500 ms. 
(The 0 ms duration of the first task is so that there is no delay in 
presenting the stimulus for the second task). All data logging is 
turned on, and like I said on most trials, it is capable of recording 
both responses.

There are a number of possibilities as to why it isn't recording 
properly, many of which I have been able to rule out (at least I think 
I have). (1) The microphone isn't working properly. I have the 
sensitivity turned up the maximum level (which doesn't seem to be 
helping very much). Also, I have another version of the program in 
which they just do the first task by itself, and that picks up every 
single response, without fail. (2) Participants are just not responding 
on every trial. I keep records of this, and no participant has failed 
to make a verbal response on any trial. (3) Participants are moving 
away from the microphone, or their voice level is dropping. I monitor 
them like a hawk, and don't notice any drop in voice volume, or 
shifting around. I can't rule this out with 100% certainty, but I see 
nothing that leads me to believe this is going on. Along these lines, I 
have also run myself through the program as a participant. I never 
moved my mouth more than 1 inch from the microphone, spoke loudly, and 
on every trial. And it still failed to record 6% of my trials for the 
task. The final thing to mention is that there seems to be neither 
rhyme nor reason to if and when it fails to record a trial. I can't see 
any pattern in the data that explains why it might be missing so many 
trials. In other words, it's not happening in a particular block of 
trials, or on every other trial, etc.

As a result, this leaves the possibility that it is a software issue. 
In other words, there seems to be something with the program that is 
not letting it record every trial as it should (maybe something I 
forgot to turn on, or off; etc.). I don't know if I have done something 
incorrectly, or if e-prime just isn't capable of doing what I need it 
to do. I'm not sure if any of you have had a similar problem (with a 
know solution), or if any of you have any advice for creating a program 
that successfully records two simultaneous responses.

I'm very sorry for the length of the message; it's a complicated 
problem that I wanted to try to explain fully. Any help or advice you 
can give me is much appreciated. Thanks!

Cheers,
Jeff

*****************************************************
Jeffrey P. Lozito
The University of North Carolina at Chapel Hill
Department of Psychology
350 Davie Hall, CB #3270
Chapel Hill, NC 27514
Email: jlozito at email.unc.edu
*****************************************************