randomizing the presentation of 2 stimuli in each trial

1
Hello,

I am really new to psychtoolbox. I am trying to write a script for my experiment. I would like to show 2 stimuli in each trial in which one of the stimuli is fixed like a pen and the other one is a randomized one from a set of images that I have. I would like to show the 2 stimuli in each trial as random meaning I don't want to always show the pen as a first stimuli. My question is how can I randomize the two stimuli so that sometimes the pen is shown as first and other times as second stimulus in each trial?

Thank you,
Armita
2
Sounds like you might be stuck with basic Matlab issues.

Google for Matlab tutorial or Psychtoolbox tutorial.

e.g.

http://argentum.ucbso.berkeley.edu/PTBtutorial

--- In psychtoolbox@yahoogroups.com, "azalea_blooming" <azalea_blooming@...> wrote:
>
> Hello,
>
> I am really new to psychtoolbox. I am trying to write a script for my experiment. I would like to show 2 stimuli in each trial in which one of the stimuli is fixed like a pen and the other one is a randomized one from a set of images that I have. I would like to show the 2 stimuli in each trial as random meaning I don't want to always show the pen as a first stimuli. My question is how can I randomize the two stimuli so that sometimes the pen is shown as first and other times as second stimulus in each trial?
>
> Thank you,
> Armita
>