OOps! (was Re: How to present the sti at a presentation location in a same list?)

[Francisco Tornay]

At 01:45 15/10/04, you wrote:
>Dear Colleague:
>
>I have an experiment which would present a fixation point at the center of
>the screen, and then at either x position=66% or 34% the stimulus (image
>file) would present.
>
>Two questions:
>1. How could  I present a stimuli for a certain period of time (i.e., 49
>msec) but the exp won't go to next trial until the subject makes a
>response?
>Note:
>Now i put 49 msec as the presentation time but the program goes to the next
>trial without waiting for the response!
>
>2. While presenting the image file stimulus, could I still present the same
>fixation point at the center location? If so, how should I do it?
>Note: I tried the "transparent" option but then the fixation point shifts
>with the image file!

I just wrote an answer to your previous question and, after that, I 
realized by this message that it had already been solved. The different 
subjects of the messages confused me.

Answers to your questions.
1. Add a blank Text Display object after your stimulus in order to delete 
it. Set the duration of this blank text display to "(infinite)".
Add a label object after the blank text display, let's call it "TrialEnd"
Go back to your stimulus properties (duration/input tab). Keep the duration 
at 49 ms. Set the "Time limit" property (at the "response options" group) 
to "(infinite)". Set the  "End action" property to "jump" and the "Jump 
label" to "TrialEnd". This way, any response would skip the blank display.

2. In order to present the fixation point, try changing the "width" and 
"height" properties of your images ("frame" tab) so that the frame size 
matches the size of the images.

Hope this helps

Francisco J. Tornay
Universidad de Granada
España