A vector graphic CRT display system

A vector graphic CRT display system for research in visual information processing is described. The vector graphic processor includes a 4K-byte display memory. The processor communicates with the controlling computer via a serial channel. The system is capable of exposure durations below 1 msec, and it allows on-line generation and modification of display files during an experiment. Brightness can be controlled separately for each vector of a picture. A graphic display editor in FORTRAN IV for interactive editing and debugging of display files has been developed.     

Rapid response and flexible experimental control with a small on-line computer: PSYCLE

This is an outline of some solutions to problems in using a relatively slow computer, without expensive peripheral apparatus, for control of psychoacoustic experiments. Major concerns were accurate timing and the ability to change from one experiment to another without extended reading of programs from paper tape.     

EyeRIS: A general-purpose system for eye-movement-contingent display control

In experimental studies of visual performance, the need often emerges to modify the stimulus according to the eye movements performed by the subject. The eye-movement-contingent display (EMCD) methodology enables accurate control of the position and motion of the stimulus on the retina. EMCD procedures have been used successfully in many areas of vision science, including studies of visual attention or eye movements and physiological characterization of neuronal response properties. Unfortunately, the difficulty of real-time programming and the unavailability of flexible and economical systems that can be easily adapted to the diversity of experimental needs and laboratory setups have prevented the widespread use of EMCD control. This article describes EyeRIS, a general-purpose system for performing EMCD experiments on a Windows computer. Based on a digital signal processor with analog and digital interfaces, this integrated hardware and software system is responsible for sampling and processing oculomotor signals and subject responses and for modifying the stimulus displayed on a CRT according to a gaze-contingent procedure specified by the experimenter. EyeRIS is designed to update the stimulus with a delay of only 10 msec. To thoroughly evaluate EyeRIS's performance, this study was designed to (1) examine the response of the system in a number of EMCD procedures and computational benchmarking tests; (2) compare the accuracy of implementation of one particular EMCD procedure, retinal stabilization, with that produced by a standard tool used for this task; and (3) examine EyeRIS's performance in one of the many EMCD procedures that cannot be executed by means of any other currently available device.     

A new breed of computer users: Rats control a cursor via joystick manipulation

Many exciting findings have been reported in the 15 years since monkeys were first demonstrated to have the capacity to perform computerized tasks. The present data indicate that albino rats can also learn to respond to computer-generated stimuli by manipulating a joystick. Although the rat’s control of the cursor is not as skillful as has been reported for primate species, it is clearly better than chance and suggests the great potential for comparative investigation afforded by use of the computer test system.     

Building a programming language for a small computer: Reinventing the wheel

The language SP-12 for a PDP-12 computer is described. SP-12 is an example of how a special-purpose language can be constructed from a set of machine-language subroutines that are called by a simple interpreter. Symbolic source programs make it easy to learn the language. Preliminary translation of the source program into binary code, using an assembler, greatly increases the speed of the interpreter.     

A computer assisted system for the extraction and visual display of pitch

The fundamental frequency of the vocal output is obtained from an accelerometer output by an adaptive filtering technique. This is converted to a voltage analogue of frequency via software on a standard PDP-8/E computer. Pitch values are either output directly or stored for subsequent display. Software is available for permanent storage and access of recorded data from backing store.     

A new breed of computer users: rats control a cursor via joystick manipulation.

Many exciting findings have been reported in the 15 years since monkeys were first demonstrated to have the capacity to perform computerized tasks. The present data indicate that albino rats can also learn to respond to computer-generated stimuli by manipulating a joystick. Although the rat's control of the cursor is not as skillful as has been reported for primate species, it is clearly better than chance and suggests the great potential for comparative investigation afforded by use of the computer test system.     

GROUPCOM: A computer program for investigating social processes in small groups

A flexible computer program for conducting on-line social psychological research is described. Using cathode-ray tube terminals, two to six subjects can communicate with one another, or one to six subjects can “communicate” with one to nine simulated others. In the latter case, the simulated information received by each subject can be independently manipulated. The experimenter has control over several features of the experimental trials, including response order, response type, method of response collection, and display format. The program can be used to investigate phenomena such as conformity, reaction to deviance, social comparison of abilities, group decision making, impression management, and leadership.     

Interpersonal referential communication experiments with a small computer

A LINC-8 computer is used with a Tektronix 611 CRT for presenting verbal information, and a slide projector for displaying facial photographs in studies of interpersonal referential communication.     

A system for computer control of auditory stimuli

A computer system for generation of auditory stimuli is described. The system produces natural-speech or software-generated stimuli for monaural, binaural, or dichotic presentation. Stimuli have been generated for experiments run both on-line and off-line.     

Mind-operated devices: mental control of a computer using biofeedback.

This study investigated whether people could learn to control a computer using a biofeedback interface that integrated their galvanic skin response (GSR), heart rate, and temperature. Twenty participants played a computer game using the biofeedback device, both individually and in pairs. Results indicated that most people learned to control the game after a single training session. The GSR measure was the most sensitive means of control. Pairs of participants controlled the device more effectively than single individuals did.     

A microphotometer for measuring luminance distributions on a CRT

A relatively inexpensive microphotometer is described. The output voltage of the microphotometer is a linear function of luminance, and the sensitivity of the photometer is sufficient for the measurement spot size of .2 mm without special averaging devices. The rise and decay time of the photometer response is less than 100 microsec, and the spectral sensitivity of the photometer can be corrected to approximate that of the human photopic eye.     

Rapid serial visual presentation display on a small screen: reading Chinese while walking

This study examined the effects of presentation unit (word-by-word or single line) and presentation duration [171, 213, 240, and 308 msec. per character (msec./C)] on the comprehension of Chinese rapid serial visual presentation (RSVP) displays read from the small screen of a mobile phone in three different contexts (seated, walking on a treadmill, and walking through an outdoor course). 30 native Chinese readers ages 19 to 26 were recruited as participants. Scores on reading comprehension showed that presentation unit and presentation duration significantly affected reading comprehension, and interactions between factors were also significant. When the presentation unit was word-by-word, no significant difference in reading comprehension was observed under different presentation durations. However, when the presentation unit was a single line, reading comprehension deteriorated with the shortest presentation duration of 171 msec./C. With regard to context, participants had a higher mean reading comprehension score in the seated context than in walking contexts, but the difference was not significant.     

Memory recall in a process control system: a measure of expertise and display effectiveness

Previous research has shown that memory-recall performance is correlated with domain expertise. In this study, a process control system was selected as a vehicle for conducting research on memory recall. The primary purposes of the present work were to determine if the classic expertise effects originally obtained in chess generalize to this novel domain and to evaluate the validity of memory recall as a measure of display effectiveness. Experts and novices viewed dynamic event sequences showing the behavior of a thermal-hydraulic system with two different displays, one that only contained information about the physical components in the system (P) and another that also contained information about higher order functional variables (P+F). There were three types of trials: normal, where the system was operating correctly; fault, where a single fault was introduced; and random, where the system's behavior did not obey physical laws. On each trial, subjects were asked to recall the final state of the system and to diagnose the system state. The P+F display resulted in superior diagnosis performance compared with the P display. With regard to memory, there was some evidence of an interaction between trial type and expertise, with experts outperforming novices but primarily on meaningful trials. In addition, memory for the subset of variables most critical to diagnosis was better with the P+F display than with the P display, thereby indicating that memory recall can be a sensitive measure of display effectiveness. The results also clarify a theoretical problem that has existed for some time in the literature, namely, the conditions under which expertise advantages are to be expected in memory-recall tasks. Collectively, these findings point to the potential benefits of adopting an applied context as a test bed for basic research issues.     

A simple graphical technique for assessing timer accuracy of computer systems

Timing accuracy is of perennial concern to researchers conducting reaction time studies, especially for those using computers that were not designed with millisecond accuracy in mind. Inaccuracies can manifest themselves in the form of quantization of the continuous time data stream. The method proposed here is simply to inspect the graph of the order statistics because quantization is readily apparent in such graphs. The method is illustrated with timing measurements of keypresses on an IBM PC.     

A contingency management technique for increasing student attention in a small group setting

Fifty-four elementary school children previously identified as consistently inattentive were involved in an extraclassroom treatment program comparing three conditions. In the E condition, attention was reinforced by making the earning of token points (exchangeable for rewards) contigent upon appropriate responses to a signal detection task embedded in the lessons. C1 condition subjects participated in the same lessons without the token system, while C2 subjects remained in their regular classrooms throughout the study. Four participating classroom teachers received brief training in behavior modification techniques for maintaining student attention. Subjects in the E condition were found to be significantly more attentive during the treatment lessons. Changes did not transfer to the regular classroom, however, and training for teachers did not affect in-class attention scores of subjects.     

An autocorrelation theory of visual form detection: A computer experiment and a computer model

A theoretical model is described for the effect of the organizational properties of dotted visual forms on visual form detection. The model assumes that a human observer functions more as an organization detector than as a feature detector. It is supported by a wide variety of experimental studies of human perception.