VSearch Color: Full-color visual search experiments on the Macintosh II

We describe an update to our visual search software for the Macintosh line of computers. The new software, VSearch Color, gives users access to the full-color capabilites of the Macintosh II line. One of the key features of the new software is its ability to treat graphics information separately from color information. This makes it easy to study color independently of form, to design experiments based on isoluminant stimuli, and to incorporate texture segregation, visual identification, number discrimination, adaptation, masking, and spatial cuing into the basic visual search paradigm.     

Pascal external functions for Strawberry Tree’s “Analog Connection Workbench” on the Macintosh

Strawberry Tree Incorporated is one of several manufacturers of input-output boards for the Macintosh computer. The Analog Connection Workbench program (Strawberry Tree Inc.) provides an icon-based programming system for these input-output boards that has most of the functions that are necessary to implement behavioral experiments. However, experimental psychologists may frequently encounter needs that the Workbench program cannot easily meet. Because the Workbench is programmed in C, whereas many psychologists are more expert in programming in Pascal, we describe, in tutorial fashion, how the user may define new external functions in Pascal on the Macintosh and integrate these functions into the icon-based Workbench programming system.     

Pupillometry system for use in social psychology

It is now relatively easy to implement pupillometry in social psychological research. We describe a system in which a Macintosh computer presents visual and auditory stimuli to subjects while monitoring an infrared pupillometer. The computer records information on subject, task, and pupil diameter into a data file for input into standard statistical analysis programs. Pupil diameter is measured continuously while subjects respond to stimuli that last for several seconds or minutes. A demonstration experiment verifies the usefulness of the system. The ability of the Macintosh computer to easily handle visual and auditory stimuli and to record responses lasting a considerable length of time makes the system well suited for studying pupil responses to complex social stimuli. This system is also well suited for the researcher initiating a research program using pupillometry. Ease of operation makes using a large number of subjects feasible.     

A goal-based perspective on eye movements in visual world studies

There is an emerging literature on visual search in natural tasks suggesting that task-relevant goals account for a remarkably high proportion of saccades, including anticipatory eye movements. Moreover, factors such as “visual saliency” that otherwise affect fixations become less important when they are bound to objects that are not relevant to the task at hand. We briefly review this literature and discuss the implications for task-based variants of the visual world paradigm. We argue that the results and their likely interpretation may profoundly affect the “linking hypothesis” between language processing and the location and timing of fixations in task-based visual world studies. We outline a goal-based linking hypothesis and discuss some of the implications for how we conduct visual world studies, including how we interpret and analyze the data. Finally, we outline some avenues of research, including examples of some classes of experiments that might prove fruitful for evaluating the effects of goals in visual world experiments and the viability of a goal-based linking hypothesis.     

Extendable high-speed stimulus generation and recording on the Macintosh computer

A new visual electrophysiology and eye-movement laboratory was developed with three goals in mind: (1) rapid execution speed for quick acquisition of data from infant subjects, (2) ease of operation by experimenters, and (3) modularity and flexibility. A powerful system composed of two linked Macintosh computers was constructed in which one computer was used solely to generate visual stimuli and the second solely to record subjects’ responses, allowing recording to execute at maximum speed without being slowed by stimulus graphics generation. A single program on the recording computer allowed the experimenter to choose the stimulus and recording parameters. The two computers intercommunicated via a local EtherNet network to coordinate recording and signal averaging. This paper presents design principles and specific programming techniques relevant to any Macintosh system that must rapidly acquire physiological recordings while simultaneously displaying sensory stimuli.     

Using HyperCard to administer a figural test on the Apple Macintosh

To date, applications of automated assessment techniques in personality testing have largely been limited to objective personality instruments with text stimuli; few assessment applications have involved graphic stimuli. Although projective personality instruments generally include ambiguous graphic or pictorial stimuli, computer applications with these procedures have been limited to automated scoring and interpretation, administration of sentence completion devices employing text stimuli, and the use of mechanical methods rather than computer graphics to display visual stimuli. In the present report, we describe a Macintosh HyperCard application for administering an objective personality test with visual stimuli, the Barron-Welsh Revised Art Scale of the Welsh Figure Preference Test. This test consists of a series of figural stimuli and a binary “like”/“dislike” response format, and it thus represents an administration procedure between standard objective self-report inventories involving text stimuli and a “true”/“false” response or variant, and tests such as the Rorschach or TAT that are both figural and free-response. The HyperCard language provides a variety of promising techniques useful for microcomputer test administration.     

Picture Perception Lab: A program for picture perception experiments on the Macintosh II

Picture Perception Lab (PPL) is a program for picture perception experiments. PPL capitalizes on the sophisticated drawing software available for the Macintosh computer by allowing the user to create stimulus images by using almost any drawing package. Through a series of user-friendly dialog boxes, PPL enables even nonprogrammers to develop, quickly and easily, tachistoscopelike vision experiments. The program allows a wide variety of experimental designs. Image exposure durations and subjects’ reaction times are precisely monitored with millisecond timing functions. Each image is drawn on the screen in a single 60-Hz refresh.     

An Apple II-based slide-projector laboratory

We describe the software and hardware of a laboratory running under UCSD Pascal on an Apple II computer. The system includes: two random-access projectors and two standard projectors, all equipped with tachistoscopic shutters; two filter wheels; a voice key; a tone generator; and eight response boxes. The laboratory can be used for any experiment in which visual stimuli are to be presented and in which precise display times, reaction times, and luminances are required. It is particularly well suited to picture-perception and picture-memory experiments.     

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.     

PsychLib: A library of machine language routines for controlling psychology experiments on the Apple Macintosh computer

The hardware and system software of the Apple Macintosh computer are described, and their implications for conducting psychological research is discussed. A library of machine language routines for presenting auditory and visual stimuli and recording response latencies is described.     

MacLaboratory Controller: A switch and A/D interface between Apple’s Macintosh and peripheral apparatus

Apple’s Macintosh microcomputer has advantages over other systems used for laboratory control and data acquisition, especially because of its graphic and user-friendly features. However, a major perceived limitation has been its closed architecture. We describe an interface using the RS 422 modem port that supports up to 64 input/output (I/O) functions including analog-to-digital 4–12 channel input. The Controller software supplies an easily edited authoring tool in which functional relationships, logical operators, timing (millisecond accuracy), and counting functions are established through simple mouse and menu commands. Data from I/O functions may be displayed or saved as tab-delimited files that can be opened by various Macintosh statistical and spreadsheet packages and that are transportable to some mainframe applications.     

Using PsyScope for demonstrations and student-designed experiments in cognitive psychology courses

We describe a plan for integrating an experimental control language, PsyScope, into under-graduate laboratory exercises of perceptual and cognitive experiments on Macintosh computers. PsyScope is a powerful and versatile system with which students can modify standard research paradigms and execute experiments of their own design, thus facilitating student-initiated independent research. Data are summarized with a general-purpose program, PsySquash, for import into Statview or SuperAnova for further analysis. This system provides an effective means of implementing student projects.     

ArtWare: Macintosh multimedia software for aesthetics research

This paper describes ArtWare, a HyperCard stack for the Apple Macintosh that allows researchers to configure and run simple experiments in visual aesthetics. ArtWare allows researchers to (1) choose paintings or other works of art from commercially available laser discs to use as stimuli, (2) create and edit sets of semantic differential response scales, and (3) create an experiment stack that randomizes the presentation of stimuli and scales as well as collects data from subjects. In addition, the paper discusses revisions planned for the current software to broaden its utility to areas beyond visual aesthetics.     

The labtop Macintosh: An interface and communications software for experiment control of animal learning research

A peripheral interface and communications software are described that allow the Macintosh Plus microcomputer to control experiments in animal learning. A Walter/Palya experiment control board (ECB; Walter & Palya, 1984), connected to the Macintosh by a RS-232 modem cable, operates as the I/O interface. The Hayes-Smartcom II software provides an easily operated communications link through menu and icon commands. Smartcom II allows the Macintosh to transmit experiment control tasks to the ECB and to collect and store obtained data. Network communication over a single RS-232 modem cable is also described.     

Contour: A hypermedia environment for teaching about subjective contours and other visual illusions

Contour is an interactive HyperCard stack for the Apple Macintosh computer, which presents users with a wealth of information (text, graphics, sound, and animation) concerning the history, theory, and methodology used in the research of a class of visual illusions calledsubjective contour illusions. The stack is divided into six sections (Introduction, Findings, Index, References, Map, and File Creator), which allow users to access differing types of information in several ways. As users navigate through the stack, they are presented with multimedia information that they can trace through author, theory, or type of illusion. The stack allows users to make notes to themselves on the information presented, to execute a literature search of the most relevant articles in the subjective contour literature, and to save them in text file for printing in a word processing program. The study of subjective contour illusions can be viewed as a microcosm of issues in the field of visual perception.     

SuperLab: General-purpose Macintosh software for human experimental psychology and psychological testing

SuperLab is a general-purpose psychology testing package for the Macintosh. SuperLab presents static visual and auditory stimuli in blocks of trials, each trial consisting of a user-specified sequence of stimuli. Responses can be recorded from the keyboard or from switches connected to an I/O board. Stimuli can be contingent on subjects’ responses, allowing feedback based on response accuracy. Timing uses Time Manager routines from the Macintosh Toolbox. Data are recorded in a text format with tabs delimiting fields, allowing analysis and presentation by other Macintosh spreadsheet, statistics, and graph-making applications. SuperLab has a Macintosh user interface for developing experiments. Psychological tasks can also be designed and modified with any application that generates a text format file.     

An external millisecond timer for the Apple Macintosh with applications to cross-modal lexical priming

The circuit and program described in this report allow researchers to use Macintosh personal computers to conduct research that requires timing with millisecond accuracy. This is accomplished with external response keys and an external clock that sends characters through the Macintosh’s serial port. For researchers interested in cross-modal lexical priming tasks, a tachistoscopic slide shutter is incorporated to allow for accurately timed presentation of visual stimuli. Because the visual display and response keys are external to the computer, display and reaction times are not subject to the timing constraints inherent to the keyboard or the Macintosh Event Manager. All circuit diagrams and code are in the public domain.     

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.     

Accurate millisecond timing on Apple’s Macintosh using Drexel’s MilliTimer

Many of the timed functions that concern psychologists, such as perceptual presentations and reaction time, are sensitive to a maximum variability in display timing caused by screen-refresh characteristics. For the Apple Macintosh, the screen operating speed is 60 Hz, which translates to an average of 8.33-msec variability. For microcomputers other than the Macintosh, a variety of hardware and software modifications to generate millisecond timing have become standard (e.g., Reed, 1979). Other than Reed College’s (1985) implementation in Rascal, which requires the Rascal development language, there has been no method of which we were aware to synchronize experimental timing with display presentation on the Macintosh. This limitation in the usefulness of the Macintosh as an otherwise excellent research tool can be overcome using Drexel University’s MilliTimer. The assembler code which follows should be considered in the public domain and can be readily adapted to any of the Macintosh-based languages.