StarPlus fMRI data

This data was originally collected by Marcel Just and his colleagues in Carnegie Mellon University's CCBI.

The Experiment

Timing: The experiment consists of a set of trials, and the data is partitioned into trials. For some of these intervals, the subject simply rested, or gazed at a fixation point on the screen. For other trials, the subject was shown a picture and a sentence, and instructed to press a button to indicate whether the sentence correctly described the picture. For these trials, the sentence and picture were presented in sequence, with the picture presented first on half of the trials, and the sentence presented first on the other half of the trials. Forty such trials are available for each subject. The timing within each such trial is as follows:

The first stimulus (sentence or picture) was presented at the begining of the trail (image=1).Four seconds later (image=9) the stimulus was removed, replaced by a blank screen.Four seconds later (image=17) the second stimulus was presented. This remained on the screen for four seconds, or until the subject pressed the mouse button, whichever came first.A rest period of 15 seconds (30 images) was added after the second stimulus was removed from the screen. Thus, each trial lasted a total of approximately 27 seconds (approximately 54 images).

Imaging parameters: Images were collected every 500msec. Only a fraction of the brain of each subject was imaged. The data is marked up with 25-30 anatomically defined regions (called "Regions of Interest", or ROIs).Stimulus and behavioral data: A variety of information is available for all three data sets, including the exact sentences and pictures presented, and the subject response times.

The Data:

The data consists of .mat files that can be directly loaded into Matlab version 7.