A VGA tachistoscope

A set of tachistoscope-emulation functions for IBM-PC-compatible computers equipped with the VGA display controller is described. C or Pascal programs including these functions can easily produce multifield tachistoscopic presentations of colored text.     

A spectacle-mounted liquid-crystal tachistoscope

A spectacle-mounted shuttering device, the Portable Liquid-crystal Apparatus for Tachistoscopy via visual Occlusion, based on light-scattering cholesteric liquid crystals, is introduced. Operating characteristics of the device are discussed with respect to the design objectives of comfort, switching speed, light transmission, light extinction, safety, and reliability. A number of practical research, clinical, and industrial applications of the spectacles as tachistoscope, stroboscope, and stereoscopic viewing apparatus are summarized.     

A computer-based programmable tachistoscope for nonprogrammers

A set of programs for on-line control of reaction time experiments is described. These programs allow a wide range of experiments to be coded in a simple form that eliminates the need for any knowledge of programming.     

A simple tachistoscope for student labs

An inexpensive tachistoscope for student labs is described that utilizes a camera shutter to control exposure duration and a potentiometer to vary light intensity. Stimuli can be drawn or typed on 3 x 5 index cards.     

A microcomputer-based visual stimulator

A microcomputer-based instrument is described that provides visual stimuli for a CRT display and collects and processes response data. The system produces a variety of visual patterns to facilitate the study of the properties of visual neurons of several different animals. The visual patterns include drifting sinusoidal or bar gratings, contrast reversal gratings, and diffuse light. By means of a keypad, the experimenter can select the visual pattern and its parameters, such as depth of modulation, spatial frequency, initial spatial phase, temporal frequency, and rotation angle.     

Apple slide tachistoscope

We outline a BASIC program and subsidiary machine language timing routines that enable the Apple II series of computers to be employed as control devices for the tachistoscopic presentation of 35-mm slides and the collection of response latencies. The program is functional for experiments that require pictorial stimuli to be presented in up to three separate fields, with precise display times, precise interstimulus and intertriai intervals, and the collection of manual or vocal reaction times with millisecond accuracy. The major advantages of this system are that initial setup costs are substantially lower than those for other similar systems (e.g., Loftus, Gillispie. Tigre, & Nelson, 1984) and that user customization of the program may be accomplished by anyone possessing rudimentary knowledge of the BASIC programming language.     

A high-resolution color graphic display four-channel software tachistoscope

A software tachistoscope for IBM-PC-compatible personal computers equipped with Tseng-ET4000-based VGA boards is described. It is shown how up to four bit-mapped color images with a resolution of up to 800 X600 pixels may be stored in video display memory and alternatingly be selected for screen display in synchrony with the vertical retrace signal of the video controller.     

A microcomputer-based laboratory: Real-world experience

This paper discusses current hardware and software in use at the Center for Automated Systems in Education, a project of the department of psychology at Southwest Texas State University. The hardware ranges from inexpensive microcomputers to sophisticated color graphic display systems. The advantages and disadvantages of various systems are considered. Current projects of interest to educators and psychologists are mentioned.     

The word without the tachistoscope

In experiments with an unlimited viewing time, we were able to isolate specific stimulus factors that lead to the word-superiority effect. We discovered that advantages of words over nonwords, and words over single letters, are caused by different factors. The word-nonword effect was found in a variety of circumstances, such as with small type, low contrast, or a simultaneously present mask. The advantage of words over single letters occurs only when the stimuli are embedded in a mask making it difficult to find a single letter. In addition, we obtained a word-detection effect without a brief exposure: Subjects were more accurate detecting the presence of words than nonwords. However, this effect only occurred when subjects were required to discriminate letters from nonletters. Thus, the word-superiority (word-nonword difference) and word-detection effects both involve letter discrimination and can be explained by similar mechanisms.     

A microcomputer-based cardiotachometer with video display

A KIM-1 single board microcomputer implementation of a cardiotachometer that provides a low-cost versatile heart-rate data acquisition system is described. Unique features include telemetry, a composite video output signal of a video frame displaying elapsed time and heart-rate, and a TV camera signal of the behavior. Data is videotape- and/or audiotape-recorded for further analysis with a larger computer.     

Measuring projection tachistoscope shutter characteristics

Projection tachistoscopes have shutters that control the presentation of stimuli. Shutter characteristics such as opening times, closing times, and mechanical reliability are important factors in applications of these tachistoscopes. The device described in this report allows the operating characteristics of shutters used in projection tachistoscopes to be evaluated. The use of the device is illustrated by measurements of three commercially available tachistoscope shutters. Each shutter was characterized by five parameters: opening and closing speeds, the lag between shutter activation and operation, the briefest stimulus presentation that the shutter allowed, and the shutter’s ability to repeat exposure durations accurately.