Response time accuracy in Apple Macintosh computers

The accuracy and variability of response times (RTs) collected on stock Apple Macintosh computers using USB keyboards was assessed. A photodiode detected a change in the screen’s luminosity and triggered a solenoid that pressed a key on the keyboard. The RTs collected in this way were reliable, but could be as much as 100 ms too long. The standard deviation of the measured RTs varied between 2.5 and 10 ms, and the distributions approximated a normal distribution. Surprisingly, two recent Apple-branded USB keyboards differed in their accuracy by as much as 20 ms. The most accurate RTs were collected when an external CRT was used to display the stimuli and Psychtoolbox was able to synchronize presentation with the screen refresh. We conclude that RTs collected on stock iMacs can detect a difference as small as 5–10 ms under realistic conditions, and this dictates which types of research should or should not use these systems.     

An experimental psychology laboratory system for the Apple II microcomputer

A system for on-line control of experiments is described that uses the Apple II microcomputer and requires no knowledge of programming. This system, APT, is used to construct test files, randomize stimulus order, and conduct experiments. Construction of an experiment is very easy through use of an interactive program. APT provides powerful options for controlling stimulus duration, feedback, and response type. Programs are available to conduct either a sequence of tests without any experimenter present or a single experiment. Over 200 subjects, ranging from 18 to 86 years of age, have completed a battery of cognitive and abilities tests using the system.     

Interfacing Apple and IBM computers for the analysis of clinical biofeedback

This paper demonstrates a method of transferring research data from a remote clinic to a large university mainframe for data manipulation and statistical analysis. Data collected by an Apple //e computer were transferred to an IBM 3031 mainframe by sending data files to an IBM PC by telephone modem or by direct hardwire connection to the PC. The IMB PC performed data-formatting routines and then uploaded the files to the mainframe for storage. Advantages and disadvantages of sending data over telephone lines via a modem are discussed.     

Writing high-quality statistical software for Apple II microcomputers

The purpose of this paper is to describe some principles and techniques that programmers should consider when trying to improve or create a statistical package. Four computational issues are discussed: accuracy, speed, computing probabilities, and error trapping. A single-array data structure is proposed for use within the program. Several other input-output issues are covered, including menus, command languages, questions, data input and editing, CRT and printer formatting, and graphics.     

An Apple II package for computer-assisted telephone interviewing

This paper describes an Apple II (an Apple-compatible) microcomputer package for a computer-assisted telephone interviewing (CATI) system. This system generates random telephone numbers within any number of exchanges that the user supplies, automatically dials the telephone, prompts the interviewer with each question, and records and permanently saves each response. It also provides a printed copy of the collected data by frequency of response in each question category. The Apple II CATI package is readily available, inexpensive, and easy to program in the BASIC language.     

AVID: An intelligent CAI system for small computers

A computer-assisted instruction (CAI) system which includes facilities for interactive graphics and for limited natural language processing has been implemented on a DEC PDP-11 minicomputer. Lesson authoring aids permit inexperienced authors to create lessons with ease and permit transporting lessons to and from other systems. The system supports eight simultaneous independent users and provides facilities for student performance evaluation and record management.     

Apple II/FIRST-Corvus networks

Our Apple II/FIRST hardware-software configuration is a cost-effective, powerful, and efficient system for experimental control, data collection, and signal analysis of research in conditioning, neurophysiology, psychopharmacology, and psychophysiology. The present report describes the enhancement of our data-processing capabilities by the addition of peripheral hardware configured to form Corvus multiplexer networks. These networks have transformed our array of Apple II/FIRST systems into multiprocessor facilities possessing the data-processing power and flexibility of far larger and more costly mainframe systems while retaining the benefits of the markedly reduced cost, great flexibility, and high processing speed of microprocessor-based systems.     

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.     

The analysis of multiphasic signals with the Apple II/FIRST microprocessor system

An Apple II/FIRST system has been developed to control classical conditioning experiments, collect analog data, and extract dependent variable measures of conditioning from uniphasic response signals (Scandrett & Gormezano, 1980). The present paper covers an expansion in the capabilities of the system by the development of a multiphasic signal analysis algorithm written in FIRST, an interactive, high-level, dictionary-based language. The program provides unprecedented efficiency, sensitivity, and flexibility in the analysis of multiphasic analog response signals in classical conditioning experiments. Moreover, the program has the potential to analyze even more complex signal patterns.     

Apple II/FIRST system control of electrical brain stimulation in the rabbit

An Apple II/FIRST system has been developed to control classical conditioning experiments, collect analog data, and extract dependent variable measures of conditioning from uniphasic (Scandrett & Gormezano, 1980) and multiphasic (Johnson, 1981) response signals. The present paper details the development of an electrical brain stimulation system as a peripheral device to the Apple II/FIRST system. In addition, data are presented that document the capabilities of the EBS system to concurrently stimulate up to eight animals while values along the dimension of each of four stimulation parameters are manipulated by a program written in FIRST. In our judgment, the EBS system has a number of advantages over currently available commercial stimulators, including cost, number of sites that can be independently stimulated, and availability of complete software control.