An introduction to microcomputer networking concepts

This paper presents a brief history of the use of internal computer networks, an introduction to networking concepts and topology, and suggestions regarding a possible system for use in a psychology laboratory. Considerations about the design and use of a microcomputer network are discussed.     

An introduction to the UCSD PASCAL system

This paper provides an introduction to the UCSD PASCAL system: a nearly machine-independent software system for micro- and minicomputers. The system is designed to run as a single-user interactive system. It is written almost entirely in the PASCAL programming language and consists of: a single-user operating system, PASCAL pseudomachine interpreter, PASCAL compiler, screen- and line-oriented editors, file manager, debugger, utility programs, and a BASIC compiler. A CAI package is also available.     

A self-contained microcomputer system for psychological testing

This paper describes a newly available microcomputer system for the on-line administration, scoring, and interpretation of psychological tests. User response to the system is reported. Results of a validity study of the system’s Minnesota Multiphasic Personality Inventory interpretative program are presented.     

Organizational preparedness for change: Staff acceptance of an on-line computer-assisted assessment system

An on-line assessment system is briefly described. Previous positive evaluation studies are summarized. Results of studies of staff acceptance and staff preparedness for change are reported. Findings are interpreted in terms of the need for planning for change. Implications related to the acceptance of other on-line computer systems in psychology are discussed.     

Visual discrimination of texture

Julesz (1975) proposed a theory of texture discrimination, based on an order statistics principle, which states that no two textures can be perceptually discriminated if they have identical second-order statistics. The experiments reported here demonstrate that this principle is not adequate to predict visual texture discriminability. Both letter and dot micropatterns were used to create texture pairs that either differed or were identical with respect to secondorder statistics. The subject’s task was to decide which quadrant of an array contained a disparate texture. In Experiments 1, 2, and 3, when controlling for spatial overlap, texture pairs having identical second-order statistics were discriminated more quickly than similar texture pairs having different second-order statistics, in contradiction to the principle. Although a significant effect in the direction predicted by the order statistics principle was found in Experiment 4 for texture pairs created from the dot micropatterns, other factors, such as spatial overlap, border differences, and goodness of pattern, must also be considered in predicting texture discriminability.     

An investigation of the perceptual basis of redundancy gain and orthogonal interference for integral dimensions

Redundancy gain and orthogonal interference for height and width were demonstrated in two experiments using a relative coding task with number of intertrial repetitions controlled. Orthogonal interference was shown to be perceptually based rather than simply an intertrial repetitions effect as suggested by Felfoldy (1974). These results from a relative coding task were discussed in terms of the previous multidimensional processing literature. It was concluded that Lockhead’s (1972t model has been applied too generally. An alternative model (a parallel, dimensional analysis stage followed by a stage in which dimensional information is integrated) was suggested.     

Influencesicture context on object recognition

The effect of sorrounding context on the recognition of objects from briefly presented pictures was investigated. Forty-eight undergraduates saw 100 msec displays of either line drawings containing several objects embedded in context or drawings of object arrays without background context. Following each exposure they were required to select from among four objects the one that had been contained in the picture. Presentation of objects in context aided recognition only when incorrect response alternatives were inconsistent with the picture context. The results suggest that context contributes to the construction of a general characterization of the pictures which provides expectancies regarding the identity of specific objects.     

Career stages: A partial test of Levinson's model of life/career stages

This study purports to test a theory of life and career stages developed by Daniel Levinson and his associates. The theory suggests four distinct stages between ages 20 and 45 each with their own developmental tasks and related behaviors and attitudes. Subjects (759 managerial, professional, and technical employees) were selected randomly from levels and departments of a major public sector employer in the midwest United States. The measure of career stage asked respondents to indicate whether they had passed through, were still in, or had not yet reached each stage as operationalized by a short vignette. Attitudinal and behavioral measures were abstracted from previously developed instruments. Only moderate support for the theory was found with little or no evidence to support the age-linked notion of these stages. Stages were found to be discriminable in terms of certain attitudes (upward mobility, career and overall job satisfaction, and job commitment) as predicted. Suggestions are given for improvements in measurement, research design, and theory refinement.     

Stress and strain in blue-collar and white-collar management staff

Previous research has demonstrated the relationship of work stress to indices of job strain, as well as underscoring the importance of moderating variables. In the present study of a mining organization it was hypothesized that personnel associated with actual mining operations would demonstrate stress-strain relationships different from those associated with administrative and staff work. Measures of stress and strain were obtained from management staff of blue-collar and white-collar groups to assess the moderating influence of collar color. Results strongly support collar color as a moderator variable. In particular, the two groups differ significantly with respect to how role conflict, job security, quantitative work load, variation in work load, and utilization of skills impact various strains. The effect of job function on stress and strain and possible practical implications of these results are discussed.     

Spatial frequency content of visual imagery

Three experiments employing the McCollough paradigm were conducted to determine the spatial-frequency content of visual imagery. In Experiment 1, large and reliable pattern-contingent color aftereffects were obtained after adaptation to visual imagery. The direction of the aftereffects indicated that subjects were adapting to higher spatial frequencies in their imagery. These results contrast with the data of Experiment 2, which demonstrate that color aftereffects obtained with adaptation to physically present stimuli are mediated by the fundamental spatial frequency components. The magnitude of the imagery-induced aftereffects in Experiment 1 equaled the magnitude of the externally induced aftereffects obtained in Experiment 2 with the same subjects. By blurring the to-be-imaged patterns (Experiment 3), the fundamental Fourier components became the salient perceptual features of the stimuli, and the direction of the imagery-induced aftereffects was reversed from that of Experiment 1, indicating that the spatial frequency content of the imagery had changed from higher to lower frequencies. Under normal viewing conditions, subjects use the higher spatial frequencies associated with the perceptually salient edges of stimuli to construct their images. The results of Experiments 1 and 3 are discussed in light of a current controversy over the nature of information representation in imagery, and it is concluded that support has been obtained for the analog model of visual imagery.