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.     

Women and crime: Issues and perspectives

Key issues in the study of female criminality are examined from the structural, individual, and small group perspectives. The literature on female criminality reflects the divergent orientation toward and interpretations of changes in the feminine sex role. Despite the amount of research done, there remain disagreements concerning the basic facts to be explained as well as the appropriate interpretation of existing knowledge.The author is grateful to Robert F. Meier, Mark C. Stafford, Robert M. Regoli, and an anonymous reviewer for their helpful comments on an earlier draft of this article. This research was partially supported by the Social Research Center at Washington State University.     

Psychosocial characteristics of pregnant and nulliparous adolescents

A case control study was carried out with 19 pregnant and 20 nulliparous fifteen- and sixteen-year-old black teenage women patients at an adolescent clinic. Both groups were measured on twenty-one variables, which included personal and family history information as well as scores on twelve scales of adolescent psychosocial adjustment. A stepwise discriminant analysis was carried out comparing both groups. The first analysis using only psychosocial adjustment variables did not significantly discriminate between the two groups. The second analysis used family history and psychosocial adjustment variables and had a multiple correlation of .65, with p = .008. The discriminant function generated was able to correctly classify 89.5% of the pregnant group and 80% of the nulliparous group. The pregnant group had lower maternal educational level, later sex education, more brothers, better family adjustment, but poorer vocational adjustment. The study suggests that distinct characteristics do exist for the pregnant adolescent in the population studied, but that such characteristics do not indicate family or psychological disturbance in pregnant adolescents. Further, the importance of the meaning of adolescent pregnancy within different cultural and socioeconomic contexts is discussed.     

Seasonal changes in open-field behavior in wild male meadow voles (Microtus pennsylvanicus)

Open-field behavior of free-living meadow voles was measured in males held overnight in the laboratory. Movement variables were positively correlated, and had negative associations with grooming and freezing. Parameters including activity, freezing, urinating, and grooming showed annual fluctuations related to the reproductive season. Together with the results of a previous study showing castration of wild voles results in altered open-field behavior, these results emphasize the role of testicular hormones in influencing this behavior. Factor analysis identified an activity component accounting for 39% of the variation, but other parameters were little simplified by this procedure. Most factors cycled annually, and significant variation was found in all eight factors during the 4-year sample. Open-field behavior varied between different reproductive and age segments of the population, and may be related to population processes such as dispersal.     

Problem-solving strategies on a partial reinforcement task: Effects of socioeconomic status and cognitive level

Differences in performance between lower- and middle-class children on partial reinforcement tasks have often been attributed to motivational differences between the groups. An alternate hypothesis suggests that different environmental experiences have resulted in differences in familiarity with problem-solving tasks. Both of these hypotheses have generated research; neither has received clear-cut support. A third hypothesis is that there is a developmental lag in the lower class so that equating the two groups on chronological age confounds the social class by cognitive-level interaction. In the present study, children were matched on cognitive abilities (preoperational, transitional, and concrete operational) and administered a partial reinforcement task. The main hypotheses that social-class differences would not be found but that cognitive level differences in success on the task and in problem-solving strategies would be found were supported. Implications were made concerning a developmental learning model that includes both qualitative and quantitative changes in abilities.     

Hermann von Helmholtz and the empiricist vision.

The philosophical convictions of Hermann von Helmholtz and the empiricist psychology he developed have been extensively discussed in historical literature. This literature has not usually emphasized the tacti assumptions about human physiology that underlaid these convictions nor the way in which Helmholtz's epistemology served as a methodological directive in his research. Helmholtz assumed nerve transmission between sense organs and the mind to be a passive process. Distortion in stimulus patterns occurs physically in the sense organs, which can therefore be treated through mechanical analogies. Stimuli become converted to the perceptions of consciousness through mental processes that are essentially analogous to conscious, inductive inference and that are therefore susceptible, in principle, to introspective investigation. This view of mental function reflected Helmholtz's intellectual debt to German idealism, especially to the philosophical views of J.G. Fichte.     

Mediation of artifacts in behavioral research

An integrative artifact model is developed from a combination of role theory and McGuire's information-processing theory of social influence. The main extraneous sources of systematic error are reduced to three conjoint mediators, the end product of which determines the likelihood that a subject will positively or negatively react to demand characteristics. Conditions thought to affect the mediating variables are noted, and the practical advantage of this combinatory view is discussed as it applies to estimating the inferential validity of experimental findings in psychology.     

The preschool behavioral classification project: An initial report

The Behavioral Classification Project (BCP), previously developed for children from 6–13 years of age, was extended to the preschool ages, the goal being to establish factorial dimensions of problem and nonproblem behaviors of children from 4 to 6 years of age. Initially, behavioral items on the BCP form not applicable to preschoolers were eliminated and replaced with new items. When completed, the Preschool Behavioral Classification Project (PBCP) form contained 268 behavioral items and 5 demographic variables. Forms were administered to 1,350 parents of 4-, 5-, and 6-year-olds, and 668 usable forms were returned. Analysis of the data was done by means of the principal components method in which the data were rotated first to orthogonal simple structure and then to oblique simple structure. Twenty-two clearly delineated factors which made nosological sense were obtained. Five additional factors were extracted and although they were not clearly defined dimensions, they contained important behavioral items.     

An improved technique for monitoring fixation in tachistoscopic tasks

A monocular lens mounted behind a stimulus screen was used to monitor fixation in a tachistoscopic recognition task. This technique was found superior to the often used “sideview technique” and as accurate as the method involving identification of a fixation stimulus. It was found that the “telescope technique” is preferable in those studies where presentation of a fixation stimulus might interfere with recognition or report of the experimental stimulus.     

An alphanumeric display program for a PDP-8

Alphanumeric and special characters composed of 5 by 7 dot matrices can be displayed on a cathode ray tube by use of a program written for the PDP-8 family of computers. The CRT surface is specified to contain up to 32 rows with up to 32 characters per row. The 35 dots defining each character require 1.5 msec to generate. Every possible arrangement of spatial and temporal organization among and between strings of characters can be created by simple parameter specification before each trial. The program is designed to operate with a minimal 4k-memory computer configuration, with no special hardware other than an oscilloscope display. The program also permits efficient on-line operation so that an entire experiment can be run quickly and efficiently without further programming. A large number of examples are detailed, and operating procedures are specified.