An acquisition and analysis system for on-line experiments on the neurophysiology of learning

An integrated hardware and software system is used in studying neural correlates of learning. The hardware system is designed to maximize experimental flexibility, while the software system is designed to maximize computer speed for data acquisition and programmer efficiency for data analysis.     

BASIC subroutines for on-line experiments using Hewlett-Packard computers

Modifications of the Hewlett-Packard version of the BASIC language to permit its use in data acquisition and control of on-line experiments are described. The resulting software system is an easy-to-use interpretative compiler.     

EMPP: An extensible multiprogramming system for experimental psychology

EMPP is a problem-oriented language developed to simplify programming of psychological experiments on a minicomputer. An important feature of EMPP is its ability to be modified as the need for more complex hardware or software arises. The basic EMPP language is summarized and exemplified in a typical experiment.     

An on-line integrator for alpha quantification

A system for the on-line graphic quantification of alpha frequencies (or other frequency bands extracted from EEG signals) is described. Alpha-frequency components (8 to 13 Hz) are actively filtered from complex EEG waveforms and presented to a laboratory-developed solid state integrator. The high-level output of the integrator, which is compatible with all popular EEG and polygraph recorders, is in the form of an ascending analog voltage ramp, reset at a predetermined level, to provide a rapid quantitative determination of alpha activity and variability. The design of the integrator permits an alternate mode of operation where time-synchronized resets, in lieu of voltage-dependent resets, produce variable height voltage ramps, whose amplitude is a direct function of the accumulated alpha activity per unit time. This method of preprocessing and signal conditioning the alpha components of the EEG waveform provides a simple analog registry of on-line real-time correlation of alpha activity with various physiological and behavioral activity.     

Software management of timing in computer-controlled on-line experiments

Some uses of clocks by programming systems which control on-line experiments contain dangers of inaccuracy and variability in the times between events. The reasons for these dangers are discussed, and an alternative approach to the problem of timing is outlined. A sample of current systems is reviewed with regard to approaches to timing, and five questions for users to ask of potential designers or suppliers of on-line programming systems are suggested in light of the considerations raised.     

An on-line psychology laboratory for teaching and research

This paper describes a PDP-15 timesharing system in which on-line experimentation and an undergraduate laboratory course co-exist with many other users. Design features include precise stimulus and response timing, easy experiment programming, easy system access, and 15 or more simultaneous users. Students can be both experimenters and subjects in realistic, variable course modules.     

An automated eye movement laboratory for on-line electrooculography

This paper describes an automated eye movement laboratory that uses electrooculography (EOG) to study people’s eye movements while they read. An on-line minicomputer processes bioelectric potentials that correspond to saccadic eye movements. Horizontal saccades larger than 1.5 deg of visual angle are detected and analyzed in real-time as they occur. The laboratory is designed for prolonged yet unobtrusive observation of human eye movements during sustained reading periods of minutes or hours. All important functions regarding data collection and data reduction are performed automatically, according to simple procedures that can be applied uniformly and without bias to nearly all subjects that we study. Results from three experiments are cited in order to quantify the performance of the laboratory with respect to four criteria: saccade detection accuracy, measurement accuracy, sensitivity, and the uniformity of these measures over different subjects.     

An analog-to-digital converter for on-line use in response dynamics research

A general-purpose translator was designed for an analysis of the dynamic properties of the intracranially reinforced (ICR) barpressing response. It is used principally as an animal training device.     

An on-line computer-based system for determining social costs and benefits

An on-line computerized program for determining social costs and social benefits for individuals in psychiatric treatment is described. The use of such a program yields a dollar value indicating how much a patient contributes to society. Mental health administrators and program evaluators can therefore be provided with information regarding the economic impact that their mental health programs have upon society. The program displays a series of multiple-choice questions on a CRT which reflect possible costs and benefits. Through the use of branching logic, unnecessary questioning is omitted. Each item is “costed” such that, upon completion of testing, a cost-benefit index is provided.     

An efficient adaptive procedure for psychophysical discrimination experiments

We present an adaptive procedure to conduct psychophysical discrimination experiments. In a discrimination experiment, an observer senses (sees, hears, feels, etc.) two stimuli (separated in space or time) and is asked to order these stimuli with respect to a particular parameter (say,s). Under the usual assumption of a locally linear internal representation ofs, perturbed by additive Gaussian noise, the probabilityP(s ₂)—of judging test stimuluss ₂ “larger” than a reference stimuluss ₁—is an error function (a cumulative normal distribution). Such an error function,Erf [(s ₂μ)/σ], is parametrized by two parameters: μand σ. The parameter μ is the value for whichP(s ₂) = 50% and is related to possible bias effects in the internal representation of the observer. The parameter σ is √2 times the standard deviation of the noise distribution and is generally called thediscrimination threshold. In this paper, we present (1) an algorithm to estimate μ and σ given the data generated by such an observer, (2) an analysis of the efficiency of a stimulus presentation with respect to the estimation of μ and σ , and (3) a method that controls the specific choice of stimulus values during an experiment so that an optimal estimation of μ and σ is obtained.     

An on-line exact small-sample test of significance for extended matching tasks

An extension of the traditional matching paradigm that enables researchers to test a variety of new experimental hypotheses is outlined. An on-line computer program that provides an exact small-sample test of hypotheses in the extended matching paradigm is described. The program, which has an intuitive graphical interface, may be accessed and executed via the Internet by using an ordinary browser.     

An on-line laboratory in cognition and perception

The design of a computer-based laboratory system requires the coordination of pedagogical and technical goals. The development of our on-line laboratory in cognition and perception is described. The laboratory consists of 11 on-line experiments in which the student participates as both experimenter and subject. The software was designed for maximum transportability: Programs were written in a low-level BASIC, with thorough documentation; flexibility is provided both within and across experiments to suit local constraints; and the experiments are supported by a student manual, instructor’s manual, and implementation notes. Criteria for selecting experiments, implementation of the experiments, and preliminary evaluation of the laboratory are discussed.     

An on-line study of Japanese nesting complexity

This paper reports the results of a self-paced reading experiment in Japanese in which the materials consisted of four versions of successively more nested syntactic structures. It was found that (1) people read the more nested materials slower than the less nested materials; and (2) the locus of the relative slowdown occurred early in the nested structures. There was no corresponding slowdown when processing the verbs at the end of each clause. The results are therefore not predicted by retrieval-based integration accounts of syntactic complexity. Rather, the results support expectation-based accounts of syntactic complexity for these materials.     

An on-line laboratory in sensation and perception

Three components of a teaching laboratory in perception are described that (1) compare several psychophysical methods for measuring visual illusions, (2) simulate experiments on dark adaptation, and (3) allow participation in auditory demonstrations or experiments. Features of special interest include: interactive use of graphics, software for simulating experiments (such as EXPER SIM, University of Michigan), and use of A/D, D/A, and TTL ports to interface special peripherals.     

An inexpensive sound-activated switch for experiments measuring vocal-response times

An inexpensive sound-activated switch suitable for experiments measuring vocal-response times is described. This switch is comparable to many commercially produced switches in terms of its control over input sensitivity and response delay times, but it can be assembled for a fraction of the cost. Additionally, the present switch provides many features not found on standard commercial models such as a built-in speaker for monitoring the input signal and output jacks to facilitate simultaneous recording of this signal. Reliability estimates suggest that performance for this switch is comparable to that of a Scientific Prototype Model 761-G when both units are equated for frequency sensitivity and response delay time. In all, this switch offers a reliable and practical alternative to commercially produced devices for experiments in which the onset of an auditory signal must be accurately detected.     

An on-line assessment of causal reasoning during comprehension

Fletcher and Bloom (1988) have argued that as readers read narratives, clause by clause, they repeatedly focus their attention on the last preceding clause that contains antecedents but no consequences in the text. This strategy allows them to discover a causal path linking the text's opening to its final outcome while minimizing the number of times long-term memory must be searched for missing antecedents or consequences. In order to test this hypothesis, we examined the reading times of 25 subjects for each clause of eight simple narrative texts. The results show that: (1) causal links between clauses that co-occur in short-term memory (as predicted by the strategy) increase the time required to read the second clause; (2) potential causal links between clauses that never co-occur in short-term memory (again as predicted by the strategy) have no effect on reading time; and (3) reinstatement searches are initiated at the end of sentences that are causally unrelated to the contents of short-term memory or that contain clauses that satisfy goals no longer in short-term memory. These results support the claim that subjects engage in a form of causal reasoning when they read simple narrative texts.