Not allowing response for a period of time

[Giorgia]

Dear E-Prime community

 

Do you know if in E-Prime there is a way to NOT allow participants to give a response for a short period of time (e.g., 200 ms), after which they will be allowed to give it?

 

Thank you!

Giorgia

[David McFarlane]

Giorgia,

I could not find an earlier answer to this, so I will write one now.
Here is how you could force a delay before a response:

- Present your stimulus, and set its Duration to the desired response
delay (e.g., 200).
- Follow that with a Wait object, and use that to get your response.

The Wait object will record an RT relative to its OnsetTime. To get RT
relative to the OnsetTime of your stimulus, you might be tempted to add
the Duration of the stimulus, but that would be a bit sloppy (e.g., it
would not take account of delays in the onset of the Wait object). The
proper method would be something as follows, assuming your stimulus is
called StimText and your Wait is called RespWait:

StimText.RTTime = RespWait.RTTime
StimText.RT = StimText.RTTime - StimText.OnsetTime
StimText.RESP - RespWait.RESP ' might as well include this

You could do that in a bit of inline code, along with any appropriate
c.SetAttrib commands.


Alternatively, if you want to get fancy, here is a way to do this
without any inline code, using StimText & RespWait for our example:

Add an input mask to StimText, with the same Allowable as for RespWait.
Set Time Limit to something like "(end of proc)" or "(infinite)", and
set End Action to "(none)". And of course add the appropriate Data Logging.

Now, as long as the subject responds during RespWait, you will get the
same response for both StimText and RespWait, except that the RT for
StimText will be relative to its own OnsetTime. One problem, if the
subject responds during StimText, it will show only the RT for that
early response (though everything else would still work).

But we could fix that: Back on StimText, go to the input mask, and
click "Advanceed...". Now increase Max Count to some suitable value,
say, 10, or 100.

Now if the subject responds during StimText, it will record those
responses plus the final response to RespWait, and the RTTime & RT will
be for only the final response, and all is well! Note that
StimText.RESP would have a string of all the responses, which you may or
may not have to deal with.

---------------
David McFarlane
E-Prime training online:
http://psychology.msu.edu/Workshops_Courses/eprime.aspx
Twitter: @EPrimeMaster (https://twitter.com/EPrimeMaster)