A computer-controlled cardiotachometer

A versatile display system for presenting heart rate information is described. The display has a table with 10 rows and 50 columns. This 10 by 50 matrix contains all integers from 0 to 499, so that it can display the instantaneous R-R intervals of a rat’s EKG to the nearest millisecond. At each beat 1 of 10 vertically and 1 of 50 horizontally arranged indicator lights are turned on to provide the coordinates for reading the table. Either beat-to-beat or averaged heart rate or period is displayed. Small and large changes can be easily and accurately observed on the same scale. The lights are controlled by a PDP-8/e. A listing of the assembler program is presented.     

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.     

A versatile microcomputer-based multiple-field tachistoscope

A newly introduced microcomputer in its most basic form provides a wide variety of stimulus display capabilities at an extremely low price. Several simple illustrative programs demonstrate its ability to present any number of visual stimuli in sequence and record response latencies, thus duplicating the functions of a multiple-field tachistoscope and associated response-recording instrumentation.     

Millisecond accuracy video display using OpenGL under Linux

To measure people’s reaction times to the nearest millisecond, it is necessary to know exactly when a stimulus is displayed. This article describes how to display stimuli with millisecond accuracy on a normal CRT monitor, using a PC running Linux. A simple C program is presented to illustrate how this may be done within X Windows using the OpenGL rendering system. A test of this system is reported that demonstrates that stimuli may be consistently displayed with millisecond accuracy. An algorithm is presented that allows the exact time of stimulus presentation to be deduced, even if there are relatively large errors in measuring the display time.     

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.     

A microcomputer-based software package for eye monitoring research

A software package is described that collects and reduces eye behavior (eye position and pupil size) data using an IBM-compatible personal computer. Written in the C language for speed and portability, the package includes several unique features: data can be collected simultaneously from other sources (e.g., EEG, EMG), logically defined events can be detected in real time on any data channel, and either of two types of data matrix can be produced. Data reduction algorithms and data structures are described.     

Visual display in the multipurpose laboratory: The benefits of video scan-conversion

A visual display system, based upon the PEP-400 video scan-converter, is described. For a cost of about $5,600, including nine video monitors, a laboratory can provide flexible, computer-generated, alpha-meric, and graphic displays simultaneously to eight subjects. Some performance results are given, as is discussion of interfacing and software required for a DEC lab system.     

A microcomputer-based system for evoked-potential augmenting/reducing measurements

Evoked-potential measurements can readily be implemented on a microcomputer. We present as an example a system for obtaining an evoked-potential augmenting/reducing measure using the Apple II microcomputer. Specialized features of the PASCAL program and peripheral equipment are described.     

A microcomputer-based laboratory for psychopathology research in rural settings

An Apple-based computer system for research use in rural mental health settings is described. Hardware and software modifications are detailed. Techniques to aid in the acceptance of psychopathology research programs in these rural settings are discussed.     

An inexpensive microcomputer-based image digitizer

An inexpensive (under $600) microcomputer-controlled image analysis system that uses commercially available components is described. Both programming and construction details are provided, as well as a discussion of the utility of the apparatus in studies of animal behavior. The system has been used to record position preferences and activity in animal groupings of various size. Simply by changing the distance between the target and the camera, animals and/or arenas of differing size can be monitored.     

A microcomputer-based technique for measuring response times in written protocols

We describe a computer system that can be used to collect response times simultaneously with written protocols. It is applicable to tasks in which written protocols and associated response times are of interest.     

Effects of word spacing on reading Chinese text from a video display terminal

This study investigated the effects of designing space between words in Chinese text, i.e., whether using a "word" instead of a "character" as a presentation unit, will facilitate the performance of reading from a video display terminal. Experimental results indicated that the main effect of word spacing significantly affected the reading time and the number of questions answered correctly. Subjects spent less time on the text with half-character word spacing or with whole-character word spacing than with conventional type (without word spacing). We also discovered that the number of questions answered correctly for stimuli with half-character spacing is significantly greater than that for stimuli with whole-character spacing, while both are smaller than for stimuli with conventional type. The additional variables, such as text difficulty and display control have significant effects as well. Our results suggested that the optimal word spacing in Chinese text should be greater than that in the traditional layout and less than a whole-character spacing. Apparently, in Chinese text, using a "word" as a presentation unit is more favorable than the traditional layouts that do not have any explicit word boundaries. The word spacing design may benefit in reading difficult or unfamiliar materials and further apply in emergency situations or in reading ambiguous sentences.     

A microcomputer-based system for continuous measurement of rodent food intake

A microcomputer-based system is described for the automatic acquisition, storage, and analysis of rodent food intakes. The feed-o-meter provides reliable, valid measurements of consumption, with minute-by-minute accuracy of ?.03 g.     

A microcomputer-based plotter system for the TRS-80 and HP 7225

A software package, MICROPLOT, was developed to run on a TRS-80 Model I microcomputer in conjunction with the Hewlett-Packard (HP) 7226 or similiar HP plotter. Capabilities include XY plotting of up to 10 data sets and curve plotting of an nth-degree polynomial. The package operates under the NEWDOS 80 Version 2.0 disk operating system but, with appropriate modification, can be run under any operating system that has dynamic program line merge and delete functions in BASIC. This report describes the structure of the system, hardware configuration, plotting capabilities, and applications in the behavioral laboratory.     

Measuring reaction time and controlling the video display in experiments on an IBM PC

The problems of using the IBM PC XT/AT or their clones in experiments are recognized because of the slow, inadequate and awkward timing procedures of these microcomputers. Some specific solutions to these problems are described, including a compiled BASIC approach using real time procedures accurate to 1 millisecond (although resolution to 1 microsecond can be achieved) and synchronization of the video display with the program. Programs are available from the authors on receipt of a 5 1/4 inch floppy disc or $10.     

DMDX: A Windows display program with millisecond accuracy

DMDX is a Windows-based program designed primarily for language-processing experiments. It uses the features of Pentium class CPUs and the library routines provided in DirectX to provide accurate timing and synchronization of visual and audio output. A brief overview of the design of the program is provided, together with the results of tests of the accuracy of timing. The Web site for downloading the software is given, but the source code is not available.     

Application of video glasses for sustained affective picture presentations: A comparison with video projector presentations

Video glasses have previously been reported to be an effective instrument for emotion induction or for reducing pain perception. In the present study, we assessed the application of video glasses within the affective picture viewing paradigm. Possible advantages of this new method were tested by a comparison with a commonly used video projector. Twenty-four participants viewed sustained picture series of pleasant, neutral, and unpleasant valence with video glasses and with a projector on different days. Affective report, heart rate (HR), and skin conductance level were measured. The results showed that the video glasses presentation mode is not generally superior to the projector mode. Instead, typical responses to prolonged presentations of emotional pictures were obtained across both modalities with valence-modulated pleasure ratings and with an arousal modulation for arousal ratings, skin conductance level, and HR. These results suggest that video glasses are as useful for presenting prolonged affective picture series as are projectors. Specific contexts in which the application of video glasses is preferential are discussed.     

An inexpensive real-time microcomputer-based cognitive laboratory system

A computer system, based on the Radio Shack Color Computer, for running experiments in cognitive psychology is described. The system was designed according to the following principles: first, all of the equipment should consist of inexpensive, off-the-shelf components; second, the language used to implement experiments should have real-time commands embedded within the character strings to be displayed, and these real-time commands should be interpreted at run time; third, the system should serve multiple subjects, yet one host should be able to run display terminals for several subjects on independent experiments; and fourth, the system should be able to interface to other display devices and other response-recording devices. Two examples of other devices are discussed: an oscilloscope for rapid visual display and an Apple Macintosh for display of pictures.