Tachistoscopic software for the Macintosh

The emulation of a tachistoscope with a Macintosh microcomputer and Pascal language is presented here. The software described is a complete program for the presentation of textual stimuli on the Macintosh screen and includes the recording of reaction times. The stimulus coordinates on the screen are user defined and variable from trial to trial for specific visual angles. The position of a fixation point on the screen and the distance between the subject and the plane of the screen, as well as the particular screen resolution, are taken into account in computing the visual angle.     

Applications for tracking reading behavior on the Macintosh

Two applications for the Macintosh that permit students to read the sentences in a text in any order also provide a record of reading behavior from which processing time and reading strategies can be determined. The applications differ: READIT! presents the sentences one at a time, whereas SELECT THE TEXT presents the entire passage with a mask, which resembles the moving window technique. Unique to these applications is that students may return to sentences to reread them any number of times and in any order. Because these applications allow students to reexamine parts of the text, the reading that they enable is more similar to normal reading than has been the case with previous methodologies for tracking student reading behavior. The applications are described, and a summary of the major results of the work in which we have used the applications is provided.     

Student statistics programs for the Macintosh

This paper reviews 15 statistics programs for the Macintosh. All are intended for student use, often in conjunction with a statistics course, and are available for under $100. Of the general-purpose programs, Data Desk and StatView offer the most appealing combination of features, Macintosh interface, and student-accessible manual. Minitab is also recommended, especially in situations where some students will be using Macs and others using PCs. In addition to the analysis-only programs, two other applications present interesting combinations of statistics and other features. DataSim offers outstanding data generation and experiment simulation along with very complete, and psychology-oriented, statistical analysis. HyperStat combines an entire statistics textbook in hypertext format with a complete data analysis package. Finally, for special situations where simple statistics are all that are required, InStat is recommended because of its tutorial features and very simple interface.     

Tachistoscopic software for Macintosh computers

The requirements for accurate presentation of short-duration stimuli on, raster display monitors are summarized, and existing packages for instantiating such displays are evaluated. A new soft-ware package that provides tachistoscopic functions for Macintosh computers is described. This software, called MacTach, performs video-buffer switching, allowing tachistoscopic presentation of large or multibit depth images that is not available with alternative methods. Compatibility routines and verification procedures allow compatibility with all Macintosh computers. Applications for animation, motion, and dichoptic presentations are discussed.     

Real-time color-frame animation for visual psychophysics on the Macintosh computer

Psychophysical experiments involving moving stimuli require the rapid presentation of animated sequences of images. Although the Macintosh computer is widely used as a color graphics computer in research laboratories, its animation capabilities are generally ignored because of the speed limitations of drawing to the screen. New off-screen color graphics structures help to avoid the speed limitations so that real-time color or gray-scale visual motion stimuli may be generated. Precomputed animation frames are stored in off-screen memory and then rapidly transferred to the screen sequentially. The off-screen graphics structures may also be saved to disk in “Picture” form as “resources” for later retrieval and playback, allowing the experimenter to build in advance a collection of moving stimuli to use in future experiments. Code examples in the C programming language are provided, and the relative strengths and weaknesses of Macin-tosh color-frame animation for psychophysical experimentation are discussed.     

A voice-activated key for the Apple Macintosh computer

An interface circuit to connect a microphone to an Apple Macintosh computer is described. The Apple Macintosh mouse port is used as the input port, and the microphone activation simulates a mouse press.     

A low-cost method for digitizing videotaped continuous movements on the Macintosh

We describe an inexpensive means of digitizing videotaped positions of moving points, such as the positions of the joints of a person who is performing an action. Single-frame video images and a Macintosh computer monitor are optically superimposed, using a half-silvered mirror, and the positions of reference points in the video image are manually clicked in by the operator, so that the screen coordinates of the reference points on each frame can be stored in a text file for later analysis. The digitizing program records comments and identifying information along with the position data.     

Computing interrater reliability on the Apple Macintosh computer

A program is described for computing interrater reliability by averaging, for each rater, the correlations between one rater’s ratings and every other rater’s ratings. For situations in which raters rate more than one ratee, raters’ reliabilities can be computed for either each item or each ratee. The program reads data from a text file and puts the reliability coefficients in a text file. The standard Macintosh interface is implemented. The Quick-BASIC program is distributed both as a listing and in compiled form; it can be run with advantage with math coprocessors.     

Using digitized auditory stimuli on the Macintosh computer

Hardware/software packages that digitize sound on the Apple Macintosh can help researchers prepare and present auditory materials needed for their experiments. Common features and benefits of commercially available sound digitizing packages are discussed in terms of some possible applications to cognitive psychology experiments.     

Software for the generation and display of random-dot cinematograms on the Macintosh computer

The software packageDotMovie 1.3.8 was designed to create and display dynamic random-dot cinematograms for studies of motion perception on Macintosh II microcomputers. In each frame of the cinematogram, some dots move in random uncorrelated directions, while other dots move with constant speed in one direction. As the relative number of dots moving in a correlated direction increases, the observer sees flow in the direction of the movement. The software described facilitates the creation of random-dot cinematograms, their presentation, and collection of data from subjects’ responses.