Joint DEC and microprocessor users’ groups report

The results of a joint meeting of users of Digital Equipment Corporation (DEC) computers and various microprocessors are reported. The meeting included a review and a discussion of Unix and of recent hardware and software products from DEC.     

CASPER: A personal computer package for exploring psychometrics

CASPER is a psychometrics software package suitable for instructional and research applications with IBM-PC-compatible computers. CASPER lets the user simulate or directly enter psychometric data. Numerous statistical analyses, file handling procedures, and graphics are included Analyses include factor analysis, multiple regression, correlation/partial correlation, moments analysis, reliability analysis, and item analysis.     

Simple software for impedance cardiography

Simple software techniques for the digital analysis of impedance cardiography data are described. The software digitizes simultaneous impedance and ECG signals, averages these signals over time on a beat-by-beat basis, processes the averaged signals to locate relevant features, and computes heart rate, stroke volume, and cardiac output for the averaged period. The source and executable code, written in Pascal for a PDP-11 with standard peripheral addressing and a VT125 graphics terminal, is available from the authors.     

Turbo Pascal timing routines for the IBM microcomputer family

Two Turbo Pascal (versions 3.0 and 4.0) software timers for the IBM microcomputer family are described: one with a 55-msec resolution and another with a 1-msec resolution. Both can be implemented without additional hardware requirements. The 55-msec timer makes use of the system-time-of-day clock; the 1-msec timer is a Turbo Pascal translation of the timer described by Bührer, Sparrer, and Weitkunat (1987). The logic of each timer is shown by a short demonstration program.     

Managing data entry of a large-scale interview project with optical scanning hardware and software

A hardware and software system for the cost-effective preparation of interview data is described. Scantron optical scanning hardware and DataBlocks software were used to prepare ASCII data files from structured interviews and questionnaires. These data were then edited for analysis with SPSS-X Data Entry software. Three different processes for preparing interview data were compared. Time, personnel, hardware, and software costs were projected for each process, as well as comparative risks to the integrity of data. A scanning procedure saves time and money, and it reduces the risk of errors.     

A real-time multiuser foreground,single-user background system for the PDP-9 computer

We have developed a software system for a PDP-9, with fixed head disk, to allow up to 16 remote laboratories to use the central PDP-9 facility for their experimental data acquisition and control needs. Timesharing is performed on a “demand” basis, using the hardware automatic priority-interrupt option. The real-time acquisition and control aspects are separated from the data reduction in the foreground by using a batch process foreground mainstream. The background is used primarily as a systems device for program updates and communications with a CDC terminal connected to a CDC 6600 computer. The philosophy, both software and hardware, developed for this heterogeneous user environment will be discussed.     

CORE: Computer-controlled operant reinforcement

A Pascal-based system and software is described for computer reinforcement of operant responding (CORE). CORE allows a single microcomputer to control up to eight different work stations simultaneously, on one of several schedules. The user need not be familiar with Pascal, although modifications of the programs require a good working knowledge. The system is menu-driven and interacts with the user in a question-and-answer format. The user can select a variety of experimental parameters, for example, session and reinforcement duration, delay, and type of reinforcement schedule. During run-time, CORE provides frequently updated on-screen graphics (Cumulative Records or Interresponse Time Distributions) and counter display. Permanently stored data and information from other counters may also be displayed or printed from the disk. Presently, three programs are implemented for a variety of related reinforcement schedules (e.g., fixed ratio, variable ratio, fixed interval, variable interval, alternation).     

Generalizing the Apple-Psych system

Each upgrade of computer hardware usually requires the development of new programming systems for psychological experimentation. Developing new software means learning a new system and unlearning an old one. To minimize this problem, a set of subroutine calls, derived from the Apple Psych system, can be implemented with different dialects of Pascal on different microcomputers.     

Screen control and timing routines for the IBM microcomputer family using a high-level language

Procedures are described for the IBM PC/AT and compatibles that measure an event’s duration with millisecond accuracy and that synchronize stimulus presentation with the vertical-retrace signal. The software is written in Turbo Pascal (Versions 2.0, 3.0, and 4.0; Borland International, Inc., 1984, 1985, 1987). Difficulties reflecting differences among video controller cards are also presented.     

Implementation of global memory models with software that does symbolic computation

A number of software tools are available that do symbolic computation that can facilitate the theoretical analysis of a mathematical model. We made use of one these tools, Mathematica (Wolfram, 1988), to implement the global familiarity memory models of Gillund and Shiffrin (1984) and Murdock (1982, 1983). We describe our implementation, and illustrate the flexibility and efficiency of use that these tools allow.     

What is Apple-Psych?

Apple Psych, a system of software subroutines written in Apple Pascal and 6502 assembly language, was designed to run real-time psychological experiments on the Apple II, II+, and IIe microcomputers. This paper describes the minimum system requirements necessary to run Apple-Psych, the capabilities of the basic system, and the advantages and disadvantages of using Apple-Psych. Because the utility of a system to a researcher is often linked to its flexibility and expandability, this paper includes a brief discussion of hardware expansions already supported by the Apple Psych software and hardware expansions that would require additional software support.     

HIPS: Image processing under UNIX. Software and applications

HIPS (Human Information Processing Laboratory’s Image processing System) is a software system for image processing that runs under the UNIX operating system. HIPS is modular and flexible: it provides automatic documentation of its actions, and is relatively independent of special equipment. It has proved its usefulness in the study of the perception of American Sign Language (ASL). Here, we demonstrate some of its applications in the study of vision, and as a tool in general signal processing. Ten examples of HIPS-generated stimuli and—in some cases—analyses are provided, including the spatial filtering analysis of two types of visual illusions; the study of frequency channels with sine-wave gratings and band-limited noise; 3-dimensional perceptual reconstruction from 2-dimensional images in the kinetic depth effect; the perception of depth in random dot stereograms and cinematograms; and the perceptual segregation of objects induced by differential dot motion. Finally, examples of noise-masked, cartoon coded, and hierarchically encoded ASL images are provided.     

Streamlining experiment data manipulation with psychology experiment data interchange format (PXDIF)

The use of small computers to automate psychology experiments has raised a number of development and logistical problems that interrupt the smooth flow of work from hypotheses to conclusions and publication. Currently, the outstanding bottleneck is the tedious and error-prone manipulation of raw experiment data in preparation for use in commercial data visualization and statistics packages. This problem is addressed by a self-describing data format PXDIF. Companion software can perform most needed manipulations automatically or with minimal experimenter involvement.     

The MED-PC experimental apparatus programming system

MED-PC is a software system that implements the MEDSTATE NOTATION dialect of state notation on IBM PC and compatible computers equipped with MED Associates interfacing. It provides a programming environment in which users can write short programs in a specialized language to control and record the events of operant and classical conditioning experiments. As many as eight experimental stations, each with up to 8 inputs and 32 outputs, running the same or different experimental procedures, may be active simultaneously. The system provides a standard set of run-time features, including mechanisms for displaying real-time data, simulation of responses, manipulation of array and variable contents, and writing of disk files. The system is based upon polling techniques, and is implemented as a translator that generates Pascal units, which are then linked to previously compiled Pascal routines.     

Against Hypothetical Syllogism

The debate over Hypothetical Syllogism is locked in stalemate. Although putative natural language counterexamples to Hypothetical Syllogism abound, many philosophers defend Hypothetical Syllogism, arguing that the alleged counterexamples involve an illicit shift in context. The proper lesson to draw from the putative counterexamples, they argue, is that natural language conditionals are context-sensitive conditionals which obey Hypothetical Syllogism. In order to make progress on the issue, I consider and improve upon Morreau’s proof of the invalidity of Hypothetical Syllogism. The improved proof relies upon the semantic claim that conditionals with antecedents irrelevant to the obtaining of an already true consequent are themselves true. Moreover, this semantic insight allows us to provide compelling counterexamples to Hypothetical Syllogism that are resistant to the usual contextualist response.     

The relationship between state anxiety and depressed mood: A validity study

The validity of the A-State Scale of the State-Trait Anxiety Inventory and the Zung Self-Rating Depression Scale was assessed using data from a general health survey. Depression and anxiety states were found to coexist, however, evidence from a factor analysis, showing items from the two tests loaded on separate factors, demonstrated that these states can be measured independently. Both the A-State and the Zung Scales were found to comprise two factors, and for each scale, one factor consisted of positively phrased items, and the other of negative items. The implications of these findings for the construct validity of the two scales are discussed.     

All about EVE: The Early Vision Emulation software

EVE, theEarly VisionEmulation software, is a set of computer programs designed to compute models of early visual processing. EVE may be used with a wide variety of models concerning spatial detection and discrimination, motion analysis, and issues of spatial sampling. EVE is modular and flexible. It runs under the UNIX operating system, and is device-independent. We describe the implementation of the EVE software and discuss how it may be applied to several visual models.     

Apple Picker: Computer software for studying human responding on concurrent and multiple schedules

Apple Picker, a software package for the Apple II microcomputer, is described. Subjects respond by searching for “apples” in two “orchards.” “Attempted pickings” may be reinforced according to random ratio or interval schedules. “Search” responses are recorded and may be examined either as rates of responding in the two orchards or visually as paths the subject has traced during the session.     

Epidemics in perspective

Irrational responses to patient with AIDS, particularly in regards to the transmissibility of HIV (human immunodeficiency virus) are examined from an historical and psychosocial perspective. Although these responses are similar to those reported from past epidemics such as plague and leprosy, they are in direct conflict with our current level of understanding regarding the transmission of this virus. Their genesis may relate to the human penchant to react to illness metaphorically. In order to allay effectively public concern about the transmissibility of AIDS, it is essential to recognize the metaphor associated with venereal disease in general and AIDS in particular.