Psychtoolbox

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Using Psychtoolbox

This MATLAB toolbox, downloadable here, is very useful for presenting text and images to subjects in behavioral and fMRI experiments and recording their response. For more information, see here

Introduction

I provide scripts which are easy to use if you have and know MATLAB. They require a dependency toolbox, a lot of which is not needed but some is absolutely required, provided here.

If you want to learn how to use Psychtoolbox, I suggest that you start from a working script and start editing to suit your own purposes. Make sure to use GetSecs to debug to make sure everything is timed just as you want it.

fMRI experiments

I provide two types of fMRI experiments using Psychtoolbox here:
Images Run File
Images Presentation File
Text Run File
Text Presentation File

These scripts are designed to present stimuli for a set amount of time and have a set InterStimulus Interval (ISI). Introduction and binary choice randomization are included. Note that there is an option to use these scripts for multiple runs (or blocks) of the same type of experiment.

Predictably, the files with Images in their name are made to present images to subjects in the scanner. The files with text, on the other hand, present text to subjects.

Behavioral experiments

Here are two types of sample Text and Image presentation scripts with Psychtoolbox.
Behavioral Image
Behavioral Text

The different between these is that the behavioral ones are self-timed. Once a subject responds, they will be moved on to the next stimulus with a prescribed ISI. Specific timing is also not debugged. Breaks are also build into these experiments, where subjects get a break every n stimuli.

If you need to modify these protocols but are not sure how, please feel free to contact me (Wesley) and I'll try to help you.