This is a Macintosh application which I originally designed for our own stimulus presentation needs at the Beth Israel Hospital in fMRI. It has grown in "power" considerably since then, but is always looking for constructive suggestions. It currently will present PICTs, sounds, QuickTime movies or text according to a script which you create using a simple text editor-like interface (the Script Editor). The most complicated part of MacStim is the script window's fields which determine how MacStim times and responds to user events. I'll explain this in more detail. The aim of many experiments is to present stimuli, and then get a response from the subject (a button press or mouse click, voice activated signal via a microphone, serial port or NuBus trigger event which I call user or stop events). MacStim will then record a reaction time (from onset of the stimulus) and move on to the next part of the experiment. The experiment consists of lines in the editor (which I call trials), each of which has several "fields" which are just text (single letters, words or numbers) separated by tab characters. Each trial can code for both a background and stimulus "resource" (ie a PICT, sound, movie or text) with the idea being that you can present the background, then the stimulus, then the background again before moving on to the next trial. You specify how long to wait in each of these sections of the trial by the "pre" (pre-stimulus time), "max" (maximum time to show the stimulus resource if the user does not respond), and "tot" (total time for this trial to last) all in seconds. There is also a useful field called "rep" which allows repetition of the whole trial to a total of "rep" seconds. This means you can repeat a trial many times (eg a flickering checkerboard) at quite fast rates before moving to the next. You can also specify the type of trial, and the supported types include: single (just a single trial, no more, no less), block (a group of trials to be blocked together eg for an animation), random (a group of trials whose order is to be randomly varied to a total time of "rep" seconds as specified in the first of the random blocks lines) and a "pause" trial (which allows you to wait for something to happen before moving on with the experiment).
The Preferences menu item contains a powerful (but complex too I guess) set of options for controlling the specific script's reaction time recording, display and resource management strategies (and settings are saved with the script for next time).
Resource types can be mixed and matched, and random blocks can contain linked trials (eg 2 trials might be inseparable if consisting of a primer trial and response trial, but randomized overall with similar 2 trial couplets).
RTs are recorded into a log window which can be edited or saved to disc like any other text file. Results are tab-delimited for ease in importing into data analysis packages or spreadsheets. A detailed on-line help system can guide you through all of MacStim's features.
MacStim works on system 6.05 & up but preferably system 7 and higher for all its features, needs as much RAM as it takes to load all your PICTURES into memory (for fast display), and runs equally well on PowerMacs and AV Macs. It will display 24 bit PICTs granted you give it enough RAM memory allocation.
This archive contains a fully working demonstration version whose only limitation is a time-limit (5-10 minutes or so). If you like it and would like to update your version immediately to the fully working version, then please follow the instructions in the "Registering" topic of the on-line help (look under the Apple menu). The current cost and how to register is fully explained there.
If I can give you any more information to assist in your decisions, please do not hesitate to tell me.
