Script for redoing a trial up to 16 times or untill response

[Julia Gomez]

Dear all,

Thank you very much for you help! I have the eprime programe almost done!
(thanks to your advices!).

I came across with a couple of more problems:

(1) Measuring RT from the first display.

As I as previously explained, I present a visual array of stimuli followed
by a blank screen upto 16 times or until response (stimArray+Blank,
stimArray+Blank, and so on). The RT measure I get is just from the last
stimArray+Blank ( the one you respond to, instead of being from the first
one). I would like to have a measure of the RT from the first display until
response (whether is one or 16 displays). Is there a way to do this?

(2) Set one stimuli from the distractor list to be target for just that
session.

I have a set of targets in a list and the distractors in a separate nested
lists. For the baseline condition, I would be ideal if I could call randomly
one of the distractors and set it to be one of the targets (for only that
session and in the following session it will become again a distractor, and,
of course, in that session is never seen as a distractor).


Any help is very appreciated.

Thanks in advance

Julia


2008/4/24 David McFarlane <mcfarla9 at msu.edu>:

>
> Julia,
>
> And here's another way to do it, without using a
> counter, and making use of functionality built in to E-Prime objects.
>
> First, I assume that your search task, with
> stimulus array and blank screen, is in a
> Proc.  Let's call that PresentationProc.
>
> Now, put PresentationProc in a list object, let's
> call that PresentationList.  So PresentationList
> has just one row with your PresentationProc in
> it, and your structure looks something like this:
>
> PresentationList
>     PresentationProc
>         StimArray
>         BlankScreen
>         TrialFinishScript
>
> Now comes the fun.  To make PresentationProc
> repeat, say, 16 times, you can do one of two
> things in the PresentationList:  (1) Give your
> PresentationProc row a weight of 16 (most users
> will find this the more natural way), or  (2) in
> the properties page of the PresentationList, go
> to the Reset/Exit tab and set it to exit after 16 cycles (my preferred
> method).
>
> OK, now your trial will last for 16
> presentations.  How to get it to stop after a
> response?  You just need one line of script in TrialFinishScript, e.g.,
>
> If Not(StimArray.InputMasks.IsPending()) Then PresentationList.Terminate
>
> That's it.  The .Terminate will make the list exit early.
>
> Now, a bit more to the lesson.  There are several
> ways for script to detect a response.  Here are
> four tests that return True if a response has occured to Stim:
> - If Not(Stim.InputMasks.IsPending()) Then ...
> - If Stim.RT <> 0 Then ...
> - If Stim.RTTime <> 0 Then ...
> - If Stim.RESP <> "" Then ...
>
> Note that .IsPending() returns False if either it
> has received a response or the response time
> limit has passed, so it only works while waiting
> for a response (i.e., it will not work afterwards
> to tell whether or not a response was received
> earlier).  Other than that, which test you use is largely a matter of
> taste.
>
> For more information on these, please see the
> List Object and InputMask Object topics in the E-Basic online help.
>
> -- David McFarlane, Professional Faultfinder
>
>
> At 4/23/2008 08:12 PM Wednesday, Julia Gomez wrote:
> >Hi everyone,
> >
> >Could anyone help with the following script? I
> >am doing a interrupted visual search task. I am
> >presenting a screen with the stimuli array for
> >the search task followed by another screen with
> >a blank screen. Once a trial has started I would
> >like this trial to repeat (i.e stimuli array and
> >white screen over and over) until a maximum of
> >16 times or  until the participant responds. I
> >created the following script but is giving me an
> >error. I am not familiar writing scripts in eprime.
> >
> >Dim count as string
> >
> >count=0
> >
> >While count<17 ' I need to repeat a trial up to 16 times or until
> response
> >    If StimuliArray.RESP = " " Then ' I am not
> > sure how to tell eprime if there is no response.
> >        Goto ShowStimAgain ' this is a label
> > that I inserted after the fixation cross
> >    End If
> >count = count +1
> >End
> >
> >Any help would be very appreciated.
> >
> >Thanks
> >
> >Julia Gómez
>
>
> >
>

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