Recording Real Time Responses
Speechy
Is there a way that I can record participants' responses and their RTs
while the subject is performing the task without sitting right beside
them and without them seeing any type of feedback on accuracy or RT?
For example, is there a way that the participant can complete a task
on one computer (without any visual feedback) but I can see his/her
responses and the RT for each trial on a different monitor in real
time? This would serve as a backup method in case the responses/RT
aren't recorded for some reason in E-prime.
Thanks
David McFarlane
In ten years of using E-Prime, I cannot think of any instance where
E-Prime failed in such a way that we would have had need of such a
backup, but I would be interested to hear from others. FWIW, E-Prime
does record everything to a text file on the disk on the fly, so even if
it crashes mid-experiment you may recover the data up to that point
using the E-Recovery program.
As for your question, I believe you could do such a thing with E-Prime 2
Professional and sufficient programming in script.
-- David McFarlane, Professional Faultfinder
David McFarlane
> Is there a way that I can record participants' responses and their RTs
> while the subject is performing the task without sitting right beside
> them and without them seeing any type of feedback on accuracy or RT?
> For example, is there a way that the participant can complete a task
> on one computer (without any visual feedback) but I can see his/her
> responses and the RT for each trial on a different monitor in real
> time?
Oh, for the record, E-Prime 1.x could also do something this, coupled
with a system called IFIS. To be fair, that required two computers
connected by ethernet, or (in an earlier version) one computer running
some specialized server software. E-Prime handed the data off to the
server, which then presented it to a separate client program for
presentation to the experimenter on a second screen. So in principle,
yes, with sufficient engineering, E-Prime, coupled with external
software, can do what you ask. But I still wonder if it is worth the
effort.
David Vinson
>> Is there a way that I can record participants' responses and their RTs
>> while the subject is performing the task without sitting right beside
>> them and without them seeing any type of feedback on accuracy or RT?
>> For example, is there a way that the participant can complete a task
>> on one computer (without any visual feedback) but I can see his/her
>> responses and the RT for each trial on a different monitor in real
>> time?
It was once possible (v.1) to do this on a single machine using the debug
window displayed on a second monitor. Inline code could be used to display
relevant content to the debug window (Debug.Print as I vaguely recall),
e.g. displaying the correct answer so the experimenter could see it.
I used this on a few occasions where I wanted to do some real-time scoring
of spoken responses, where offline scoring would not have been sufficient,
e.g. signaling that speech errors of certain kinds had occurred and
therefore a trial must be repeated later. The subject had the button box
and microphone (for voice relay) and I had a keyboard to signal "error"
during an intertrial period, unbeknownst to the subject.
I too am not sure why you would want to verify accuracy and RT by hand!
david
Dr. Dave Hairston
years with very good success.
Simply, what you need is a video card with two outtputs ("Dual-head").
Almost any card will do this nowadays; I'm partial to nVidia myself.
But anyhow, from that card, run 1 of the two lines itno a video
splitter box, so that you have 1 line in, 2 lines out... now you have
3 monitors, and 2 of them show the same thing. CAUTION - get a good
splitter with it's own power supply, the cheap stuff gives terrible
images.
Now place 1 of the "cloned" onitors in teh room with your subject, and
the other two outside in your "control room" or whatever.
E-Prime will automatically run the paradigm on the monitor that is
designated as "primary" in Windows... so set your cloned monitor to
this one, and move your E-Editor window to teh other one (I call this
the "experimenter's window" b/c teh usbject now cannot see it!).
Now you can see the Debugger window WHILE YOUR SCIPT IS RUNNING and
your subject cannot... cool...
Just use very simple code after the response recording object to
report back the .RT or .ACC status after each trial; for example the
line:
debug.print Response. Acc & " " Response. RT
will print out "1 345" or similar after each response.
>>Why would you want to do this???
Well, sometimes you need to know how your subjects are doing on-line;
perhaps they are in training and you wish to ensure they know what
they are doing.
In my case, I'm having usbjects do an adaptive staircase procedure...
and as we all know, staircases are notoriously flaky... and if people
get off track, it throwsteh whole procedure out of whack. So, I watch
their progress trial-by-trial to be sure they're progressing as
expected.
Hope that helps!!
Dave
P.s. - in theory, I believe EP 2.0 is supposed to support multiple
monitors. If this is the case, one could have it report status
directly to teh 1nd monitor which only teh experimenter can see, and
avoid the whole debugger window bit.....
Spape, Michiel
Hope that helps.
Best,
Michiel M. Spape
Cog.Psy. Unit
LIBC & LUIPR
Leiden
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David McFarlane
>A colleague of mine invented a procedure much like this, but
>somewhat simpler, if less elegant. With voice-key type of
>experiments and a simple monitor splitter, he typically showed
>feedback on the bottom edge of the screen (acc, rt). Most monitors
>have a little menu built in which permit aligning the screen
>manually, so he moved the participant's screen a little down -
>hiding the feedback - whilst keeping his own normal.
That would do the trick. And if you really wanted to go crude and
old school, you could use two monitors as above, and without any
adjustment just tape or cover up the bottom of the subject's screen
so they cannot see it.
Dr. Dave Hairston
be sure that it supports the total badnwidth of the signal that you
are sending. Often we (at least I!) are running at fairly fast refresh
rates (hopefully < 10 ms, if you have the right equipment you can hit
5 ms) and screen resolutions for having good tight experimental
control. Some splitting boxes (the cheap ones) officially only support
slow (e.g., <100 Hz) refresh rates and/or low resolutions. What will
happen is that if you exceedteh capacity of the box, the two monitors
may either (a) not actually stay in sync with either other, so the
timing of what you (the experimenter sees) and your subject may not be
true, and (more importantly) you don't really know if the time
reported by E-Prime is accurate... or (b) the image will be terrible
or simply shut off.
I like the cheap and elegant tape-over-the-response solution... but
why would you want to do that for only 10 cents and 10 seconds of
work, when instead you could waste 3 days and thousands of valuable
research dollars with the more complicated route?? ;-)