A Resource Finder is provided to assist in entering the script information since this can be particularly tedious. To use the Resource Finder, select Find Resources... under the Control menu.
1. After the dialog box appears, click the Open... button to display the standard file open dialog box. Navigate through the folder system to find the location of your intended stimulus files. Click the Use These button, and a list of available filenames will appear in the background and stimulus item list boxes at top (with "None" as the default and first one).
2. Only usable "PICT", movie ("MooV") and "snd " (in "sfil") containing files will appear. A small icon at the top right of each list shows the file type of your current selection. Note that the file names have had a suffix added to assist in identifying the file type ("p", "m", "s" for picture, movie or sound files respectively) but this will not appear in the script. Also note that MacStim will try to get a sound file out of a non-sfil designated file if you explicitly specify a file name of a sound file in the script.
3. Adjust the timing settings using the editable text boxes (all times are in seconds to 3 decimal places).
4. Click "Enter" to put one trial into the script.
5. Repeat this process until you have entered all your required trials. Note that times are in decimal format, but you do not need to specify all 3 decimals places, and most fields will accept negative times (except the "rep" field) to indicate you wish a random range up to the absolute value given to be used during the experiment. Note that tabs separate fields. The tabs make the results easy to copy and paste into a spreadsheet application for subsequent analysis (or vice versa).
Creating Pictures
1. PICTs can only be "played" by MacStim. You have to create them yourself but there are some tricks to know before drawing them (or MacStim may not display them as you intended).
2. You can draw PICTs with any number of other applications offering "drawing" tools (eg PhotoShop, MacDraw, Canvas, ClarisDraw, MORE, PowerPoint etc). Once you have created the picture, save it as PICT (or PICT 1 or PICT 2) format. (For the technocrats, MacStim will only use PICT files with their data in the data fork, not PICT resources).
3. The way you draw your PICTs is important!
a. Pictures in version 2.1.6 and higher do not have to be the same size any more! It is a useful technique to get accurate positioning to include a background rectangle of the correct dimensions (filled with the desired background color or none) behind all the picture elements, and in the same position with respect to them all. MacStim will center each picture around the default center but no longer makes all offscreen gworlds the same size. This may allow some RAM savings. The disadvantage is now that you need to run the test to see if you have enough RAM allocated to load all your pictures, ie no more "pre-flighting" (which was only a guess anyway). MacStim will endeavour to preload all resources, but if it fails, it will try to continue and load them on-the-fly. The only way to see if this is successful is to try it.
b. Keep your PICTs as small as possible. This decreases memory (RAM) needs, which may be important in RAM limited systems (especially with deep color monitors or very large screens).
c. You can choose the background color. This can match the background of the PICT files whose elements can then be much smaller, but give the impression that your picture fills the entire screen. The background color is set using the Preferences menu item under the File menu.
d. If all you wish to display is text (& < 32 chars), then consider using the direct text display option, which doesn't need as much RAM, is much faster to create scripts and can be mixed in with PICTs of crucial or "odd-ball" items.
e. The new option to horizontally or vertically shift a trial's elements makes animations a whole lot simpler. You can now just draw a single (or a few) images of the correct size and adjust their screen positions for the desired effect. See the Bouncing Ball script for an example.
f. Also note that you can flip PICTs & text in MacStim horizontally, vertically or both (see the Display pane of the Preferences dialog). Note that you cannot flip movies at present in the same manner (these are created on the fly). This is useful if your video projector output is found to be incorrect (and it doesn't support a flipping option). Be aware though that text and PICTs flipped after being loaded on-the-fly may be excruciatingly slow (especially for large horizontal flips). Sorry but there's no way around this since it occurs only when memory is tight for pictures and is an poor-man's fix for flipping that should be done by a video-projector in the case of text.
4. Knowing these rules, you can efficiently use your available RAM and ensure screen drawing is as fast as possible. If you really do need to use all the available screen space then do so, but be aware that MacStim may find you don't have enough RAM for this (though every possible effort is made to accommodate your needs before failing). Your only solution then is to increase the RAM partition of MacStim (use the "Get Info" menu item in the Finder as described in the next help section under "Color monitors", and in your Mac manual).
5. Think carefully about what you wish to display. For example, flashing stimuli are at minimum just two pictures with slightly different elements. PICTs can be displayed quite rapidly (theoretically up to 60 frames/second), and the impression of movement (animation) can be created with carefully constructed serial pictures (2 per trial). PICTs can effectively be drawn in bitmap applications as well. Animations can consist of a few elements moved (ie horizontally and vertically shifted) around the screen rather than many hundreds of individual pictures. These are an efficient way to create even complex pictures and will usually take up less memory.
Creating QuickTime Movies
These must be made in another application, though the Movie Preview… Control menu option does allow you to edit already existing movies (eg using the Cut, Copy, Paste menu commands).
Movie playback supports the full range of QuickTime formats, compressions and sizes though speed of playback will depend upon these and the CPU speed of your Macintosh. It is recommended that you do not use compression, ie keep the movies in 'raw ' format if you want them to play quickly and have a relatively slow Mac. At present any options you set in the Movie editing application or via the Movie Preview… menu item are overridden globally by those in the Preferences… dialog view for Movies. Unfortunately the custom playback options are not saved with the Apple movie format, so any special options (eg looping) must be set before an experiment using the Preferences… settings. At present the movie will be replayed during the experiment at the same size as you saved it (if you saved it scaled using the Save All As…, then it should also do so during playback).
The Movie Preview… menu item displays a dialog with a movie control within it. Use the Open menu item (File menu) to load a movie for playback and editing. The following notes describe the options and key equivalents available in the preview window. Note that these are not available during the experiment.
Controller Shortcuts
The following shortcuts are available when using Apple's standard movie controller. If the movie controller is not visible, then only the key-based commands will work.
Play: Double Click (on image)
Play Backward: Command-Left Arrow Key
Play/Pause: Return Key or Space Bar
Pause: Single Click (on image) or Command-Period
Step Forward: Right Arrow Key
Step Backward: Left Arrow Key
Jump Forward: Option - Step Forward
Jump Backward: Option - Step Backward
Increase Volume: Up Arrow Key
Decrease Volume: Down Arrow Key
Mute: Option-Click Volume Button
Change Speed: Control-Click and Drag in Step Buttons (at right of controller)
Frame Selection
Movies can be edited by selecting frames with the movie controller and then using the standard edit menu items to cut, copy, paste, or clear frames.
To select more than one frame, press the SHIFT key and drag the controller thumb across the frames that you wish to select. To deselect all frames, click in the play bar (the bar in the middle of the controller) but away from the thumb.
To extend or reduce the size of a selection by a single frame, move to the start or end of the selection, hold the SHIFT key down, and click the Step Forward or Backward buttons, or press the Left or Right Arrow keys.
To deselect all except the current frame, hold the SHIFT and OPTION keys down, and click the Step Forward or Backward buttons, or press the Left/Right Arrow keys.
You can also select frames as they are being played. To do this, move to the first frame to be selected, then hold the SHIFT key down and click the play button (the button at the left of the play bar). The frames played will be selected until the movie is stopped or the SHIFT key is released.
Pop-Up Menu
Many common movie options cannot be adjusted from the standard controller. Some of these are available via a pop-up menu than can be popped up by pressing the OPTION and COMMAND keys while clicking the window containing the control. The options supported are:
Loop - movie will play continuously
Loop Back and Forth - movie will play forward then backward (Loop must also be checked)
Play Selection Only - will play only the frames that are currently selected in the movie controller
Play Every Frame - QuickTime normally preserves the flow of time in a movie and will skip frames if the hardware cannot keep up with the movie. Checking this item forces each frame of the movie to be played, even if this slows down playing of the movie.
Load Movie into RAM - Loads the entire movie into RAM (if enough memory is available). This can improve movie playback performance.
Set Poster Frame - makes the current frame the movie's poster frame (this is typically the single frame of the movie that best represents the movie)
Go To Poster Frame - shows the poster frame
Creating Sounds
These also must be created by you in another application.
1. They should be saved as 'sfil' resources (which is the usual format for sound resources). Sounds are also pre-loaded into memory during preparation of the experiment.
2. Test your sounds before using them in an experiment. Larger sounds can be made smaller if they are repetitive.
3. MacStim will look extensively in the sound resource fork of the named file for the same named resource. If it does not find a sound resource with the same name as the file, then it will use the first sound resource in that file (it assumes only one sound file resource in each file presented to it and that this is of course the one you intended!).
