Microfeedback: Biofeedback Monitoring Using Home Computers - a Pilot Study

The increasing focus on information technology has led to widespread growth in the use of microcomputer systems in counselling settings. While many applications depend on expensive and sophisticated equipment, the humble home computer has many facilities to offer. High resolution graphics and versatile control interfacing, designed for games use, enable easy adaptation to tasks such as visual presentation of biofeedback with the facility for data retention and analysis. A pilot system based on the Commodore 64 is described.     

A simple system for displaying alphanumeric characters on an oscilloscope using an AIM-65 microcomputer

A simple system for displaying alphanumeric characters on an oscilloscope screen is described. It may be useful for those applications in which only a few chaxacters should be shown, but within small time limitations. The system, using an AIM-65 microcomputer, is capable of exposure durations below 100 microsec/character. Possibilities of speeding up the system and designing characters are indicated.     

3-D graphics animation program for the Apple II

A graphics design program for creating point-light displays of transforming 3-D objects is presented. This program was written for an Apple II microcomputer interfaced to a Texas Instruments TMS 9918A video display processor. In contrast to other 3-D design programs, it uses individual point-lights undergoing circular trajectories as a design primitive. An editor enables the user to enter and edit specific motion parameters for defining the parallel projection of as many as 16 point-lights on the screen. These parameters are then used to calculate and store in an animation list the screen positions of each point-light for each frame. Number of frames to be displayed and display rate are user defined.     

A multiprocessor system for generating visual displays and controlling experiments

A laboratory is described that is based on an IMSAI 8080 microcomputer and an IMLAC graphics display system. Procedures for using the system are described and illustrated.     

A microcomputer interface for control of real-time experiments in cognitive psychology

A microcomputer system for real-time control of experiments in cognitive psychology is described. The microcomputer serves as an interface that allows a remote timesharing computer to control the timed display of textual material on CRTs and collect response times accurate to 1 msec. It can control two CRT subject stations presenting the same or different experiments and control other devices such as slide projectors and tape recorders. It is argued that such special-purpose microcomputer interfaces provide a real-time laboratory with significantly less effort than does the more traditional laboratory minicomputer.     

A real-time control system for CAI and prothesis

An integrated hardware and software system was used for the real-time control of text display in a CAI environment. Reliability and cost considerations led to the development of a digital EOG transducer, which was used in conjunction with a KIM-1 microcomputer. This paper traces the development of that system from a complex and expensive PDP-11-based system to a microcomputer firmware approach. Such a system could, in real time, accomplish a similar display task for severely handicapped nonvocal individuals.     

Programming experiments on a TERAK 8510/A microcomputer

In the course of bringing up one’s first experimental microcomputer system, certain standard problems occur that are trivial to the experienced programmer but are great blocks to the novice. In this spirit, some paradigms that were implemented on a TERAK 8510/a microcomputer, and the related problems, are described. Specific topics include some consideration of timing procedures for reaction time experiments and how to handle large text files on small floppy disk systems.     

A microcomputer interface for applications requiring large numbers of subjects

While most small microcomputers are powerful enough to control intricate experiments, a major limitation of many is their limited I/O capability. An interface for the KIM-1 or similar small microcomputer is described that provides for up to 128 or more inputs. The basic components of the interface are a series of shift registers through which the incoming data are manipulated and read by the microcomputer. Provisions are also made to latch the incoming data, allowing detection of very high rates of or even simultaneous data input. The interface is modular in design and can be expanded by increments of eight inputs. Use of the system to monitor a large number of running wheels is discussed.     

A microcomputer-controlled laboratory: Hardware

A microcomputer-controlled laboratory designed to incorporate the Motorola 6800 microprocessor unit is described. The microcomputer system is reliable, flexible, and expandable, as well as adaptable to the next generation of Motorola microprocessor components. A modular system design utilizes multiprocessing with separate microprocessor units dedicated to specific functions. This computer, when used with powerful, high-level software, provides a general-purpose psychology laboratory computer system that is easy to use.     

Inexpensive microcomputer systems for research and instruction: A dream or reality?

This paper presents a detailed introduction to two microcomputer systems useful for research and instruction. The systems are ready for immediate use, fully assembled, and require no knowledge of electronics. They also possess the high-level programming language, BASIC, which can be easily learned by researchers and students. The application of microprocessor technology and mass production has allowed the cost for a single microcomputer to be reduced to about $600. At this price, virtually any psychology department or individual researcher can begin to employ computer technology in psychological research and instruction. The hardware specifications, software characteristics, criteria for selection, and possible applications of these systems are considered, with emphasis on use in psychological applications.     

Direct measurement of the system latency of gaze-contingent displays

Gaze-contingent displays combine a display device with an eyetracking system to rapidly update an image on the basis of the measured eye position. All such systems have a delay, the system latency, between a change in gaze location and the related change in the display. The system latency is the result of the delays contributed by the eyetracker, the display computer, and the display, and it is affected by the properties of each component, which may include variability. We present a direct, simple, and low-cost method to measure the system latency. The technique uses a device to briefly blind the eyetracker system (e.g., for video-based eyetrackers, a device with infrared light-emitting diodes (LED)), creating an eyetracker event that triggers a change to the display monitor. The time between these two events, as captured by a relatively low-cost consumer camera with high-speed video capability (1,000 Hz), is an accurate measurement of the system latency. With multiple measurements, the distribution of system latencies can be characterized. The same approach can be used to synchronize the eye position time series and a video recording of the visual stimuli that would be displayed in a particular gaze-contingent experiment. We present system latency assessments for several popular types of displays and discuss what values are acceptable for different applications, as well as how system latencies might be improved.     

Eye-gaze-contingent control of the computer interface: Methodology and example for zoom detection

Discrimination of user intent at the computer interface solely from eye gaze can provide a powerful tool, benefiting many applications. An exploratory methodology for discriminating zoom-in, zoom-out, and no-zoom intent was developed for such applications as telerobotics, disability aids, weapons systems, and process control interfaces. Using an eye-tracking system, real-time eye-gaze locations on a display are collected. Using off-line procedures, these data are clustered, using minimum spanning tree representations, and then characterized. The cluster characteristics are fed into a multiple linear discriminant analysis, which attempts to discriminate the zoom-in, zoom-out, and no-zoom conditions. The methodologies, algorithms, and experimental data collection procedure are described, followed by example output from the analysis programs. Although developed specifically for the discrimination of zoom conditions, the methodology has broader potential for discrimination of user intent in other interface operations.     

Microcomputers in social psychophysiological research: An overview

Microcomputer systems have become commonplace in the psychophysiological laboratory during the past 5 years and are currently used in all phases of data acquisition, experimental control, and data analysis. In the past year, however, advances in microprocessor technology and scientific software have greatly extended the capabilities of these desk-top systems. Small laboratories now can afford an integrated laboratory microcomputer system and both the high-fidelity data acquisition hardware and the sophisticated analysis capabilities traditionally found in large minicomputers. We briefly describe the demands that social psychophysiological research can place on computer systems, the system presently employed in our laboratory, and a system being installed to overcome limitations on sampling rate, sampling periods, and waveform analysis.     

A microcomputer system for controlling classical conditioning experiments

A microcomputer-based laboratory system for controlling stimulus presentations and data acquisition in classical conditioning experiments is described. The system comprises an Intel 386/486-based microcomputer and a commercially obtained low-cost counter/timer board with input/output lines for stimulus timing and external device control. A simple, yet versatile custom-designed structured programming language is provided for performing an unlimited number of stimulus configurations and their sequences. In electrophysiological studies, the system can be flexibly connected to computer-controlled signal conditioning systems for the amplification and filtering of multiunit and evoked field potential responses and to high-speed data acquisition systems for sampling and analyzing the responses. The costs of reserving an entire microcomputer for experiment control are well compensated for by the simplicity and efficiency of programming and transportability of the control protocols between different setups and laboratories. Furthermore, a data acquisition and analysis system most suitable for the aims of a research project can be selected.     

Computer programming for generating visual stimuli

Critical to vision research is the generation of visual displays with precise control over stimulus metrics. Generating stimuli often requires adapting commercial software or developing specialized software for specific research applications. In order to facilitate this process, we give here an overview that allows nonexpert users to generate and customize stimuli for vision research. We first give a review of relevant hardware and software considerations, to allow the selection of display hardware, operating system, programming language, and graphics packages most appropriate for specific research applications. We then describe the framework of a generic computer program that can be adapted for use with a broad range of experimental applications. Stimuli are generated in the context of trial events, allowing the display of text messages, the monitoring of subject responses and reaction times, and the inclusion of contingency algorithms. This approach allows direct control and management of computer-generated visual stimuli while utilizing the full capabilities of modern hardware and software systems. The flowchart and source code for the stimulus-generating program may be downloaded from www.psychonomic.org/archive.     

The AIM-65 microcomputer as a laboratory control device

The AIM-65 microcomputer is a self-contained system equipped with several useful peripheral devices. Its low cost and versatility make it an attractive device for the control of laboratory equipment. This article describes the AIM-65 and illustrates some possible applications.     

Design and implementation of a microcomputer-based adaptive testing system

Adaptive testing is a relatively new form of test administration in which a test is tailored to the individual taking it by choosing items most informative about that person. Methods for determining which items are most appropriate take on a variety of forms, some requiring extensive computation, and almost all requiring administration by a computer. The increasing availability of inexpensive microcomputer systems has made adaptive testing possible when access to larger computer systems is impractical. To make implementation of a variety of adaptive testing methods feasible on a microcomputer, a system efficient from both the examinee’s and the test constructor’s perspectives is necessary. This paper begins by briefly outlining the strategies of adaptive testing developed to date and showing how, structurally, they can be grouped into three general categories. Considerations in design of a test-specification subsystem are then discussed as they relate to this categorization. Finally, a specific implementation of a subsystem for use under the CP/M microcomputer operating system is described. Techniques used to make the extensive computations required by adaptive testing feasible on a microcomputer are presented.     

Can a small dedicated machine find happiness in a company that pioneered time-sharing?

In the context of an automated psychophysical laboratory, the adequacies and inadequacies of a small computer are discussed. Attention is given to the rationale for choosing the implementation in particular a dedicated small system as opposed to time-shared use of a larger system. The variables discussed include cost, flexibility, language level, and storage capabilities in addition to reliability. A compromise position that appears most viable for the future is also suggested.     

Using an Apple II to control a two-field projection tachistoscope

A suite of programs is described that enables an Apple II+ microcomputer to control slide projectors and shutters as a two-field projection tachistoscope. This system is portable and allows more precise exposure timings and more complex visual stimuli to be used than are possible with earlier systems.     

A low-cost high-speed digital data acquisition and display system

A flexible and inexpensive data acquisition and display system based upon the KIM-1 microcomputer module is described. A simple signal-conditioning circuit and program are shown that will allow events to be counted at rates to 1,000/sec and stored in successive time bins. The program counts events from each of two event detectors and stores the count of each detector in an independent set of time bins. Up to 127 16-bit bins are available to each event detector and bin width can be varied from 1 msec to 1 min. A separate input can be used to time-lock data collection to a specific stimulus allowing poststimulus histograms or IRTs to be collected. The collected data can be sequentially displayed as a decimal number on a built-in LED display and stored for later analysis on an inexpensive audio cassette recorder.