An inherent problem in certain constant-current stimulators

A basic and potentially dangerous problem that may occur in the use of triggered constant-current generators for stimulation is discussed in the general case. A solution with schematic illustration is presented for one specific constant-current generator, the CCS-1A manufactured by Electronics of Life Sciences, Inc.     

Ultimate choice between two attractive goals: Predictions from a model

A mathematical model for two-choice behavior in situations where both choices are desirable is discussed. According to the model, one or the other choice is ultimately preferred, and a functional equation is given for the fraction of the population ultimately preferring a given choice. The solution depends upon the learning rates and upon the initial probabilities of the choices. Several techniques for approximating the solution of this functional equation are described. One of these leads to an explicit formula that gives good accuracy. This solution can be generalized to the two-armed bandit problem with partial reinforcement in each arm, or the equivalent T-maze problem. Another suggests good ways to program the calculations for a high-speed computer.Support for this research has been received from the National Science Foundation (Grant NSF-G2258), the National Institute of Mental Health (Grant M-2293), and the Laboratory of Social Relations, Harvard University.We wish to acknowledge and express our appreciation for the cooperation and assistance given by Phillip J. Rulon, Albert Beaton, Wai-Ching Ho, and Donald Spearritt, who set up, programmed, and executed numerous calculations connected with the linear equations method of solution, and by Cleo Youtz for extensive calculations at every stage of the work. We also wish to thank Ray Twery and Robert R. Bush for permission to use in Table 3 some of the unpublished results of their calculations. Those calculations were made on the Illiac through the cooperation of the Digital Computer Laboratory of the University of Illinois, Dr. John P. Nash, Director.     

Wind as an aversive stimulus

Two monkeys were trained on an escape-avoidance procedure in which a lever press delayed exposure to wind by 20 sec. For 5 hr, subjects alternately worked 15 min and rested 15 min, and performed this schedule when the wind was 5, 10, and 20 mph and the temperatures were 50, 60, and 70° F. Analysis of variance showed that the percent of wind avoided was related to both the velocity of the wind and the temperature during the exposure. When the wind was 10 and 20 mph it was avoided almost continuously regardless of the temperature.     

High-Trait and Low-Trait Angry College Students: A Comparison of Family Environments

In this study the authors investigated differences in the family environments of high- and low-trait angry college students. High-trait angry students described their family environments as significantly less cohesive, less emotionally expressive, more conflictual, and more disorganized than did their low-trait angry counterparts. Implications of the findings to the counseling of students with anger-related problems are discussed.     

Lotus 1-2-3 simulation of frequency encoding on the basilar membrane

A spreadsheet simulation was designed to describe frequency encoding on the basilar membrane according to the place theory (Greenwood, 1961). For any given frequency, the simulation displayed the location of maximum amplitude on the basilar membrane and the relevant critical bandwidth. The authors found a very high correlation between data given by the simulation and data from empirical research. The high correlation indicates the validity of the place theory of frequency encoding and the usefulness of this simulation for future research purposes.     

Matrix manipulation and interpretation of data related to AIDS transmission

This research describes how a currently available spreadsheet program can be set up to analyze sociographic data. An algorithm developed by Jamrich (1960) is presented, along with both the mathematical and the spreadsheet equations. An example of the application of the algorithm and equations to AIDS transmission data is presented.     

Hemispheric differences in the interference among components of compound gratings

The relationship between local/global and high/low spatial-frequency processing in hemispheric asymmetries was explored. Subjects were required to judge the orientation of a high- or low-spatial-frequency component of a compound grating presented in the left visual field (LVF) or right visual field (RVF). In Experiment 1, attention was focused on one or the other component. A signal detection analysis indicated that sensitivity (d′) to the high-spatial-frequency target was reduced more by the presence of the low-spatial-frequency component when both were presented in the LVF rather than in the RVF. In Experiment 2, subjects determined whether a target orientation was present, independent of spatial frequency at only a single level (i.e., at the high- or low-spatial-frequency level), as opposed to both or neither level. An RVF/LH (left hemisphere) advantage was found when the decision was based on the orientation of the high-frequency component. The asymmetrical influence of visual field of presentation and spatial frequency upon sensitivity is discussed in terms of hemispheric differences in the magnitude of inhibition between spatial-frequency channels and in the role of transient channel activity to capture and direct higher order attentional processes.     

The impact of methodological factors on child psychotherapy outcome research: A meta-analysis for researchers

Two recent meta-analyses have generated evidence for child and adolescent psychotherapy effects. However, critics note that such meta-analyses often include studies with methodological shortcomings which might invalidate their results. In the present study, we explored whether the results of the most extensive child/adolescent meta-analysis might have been influenced by such methodological variables, focusing on internal validity and external validity factors. Together, these factors accounted for two-thirds as much variance as the substantive factors (e.g., type of therapy, age) in the original metaanalysis. This suggests that relative to these therapy and child-characteristic variables, methodological factors have a substantial, though smaller, impact on metaanalysis results. In general, increased experimental rigor was related to larger effect sizes; this argues against the hypothesis that methodologically weak studies have led to an overestimate of therapy effects. No significant interactive relations were found between validity factors and predictors of outcome; this suggests that the relations noted in previous metaanalyses between outcome and various variables were notdistorted by the validity factors tested here.The research described here was supported in part by grants from the North Carolina Department of Human Resources, Division of Mental Health, Mental Retardation, and Substance Abuse Services (41626), and from the National Institute of Mental Health (1 RO3 MH38450). The authors gratefully acknowledge the assistance of Todd Morton, who provided reliability coding.     

An evaluation of differential prediction of WIAT achievement scores from WISC-III FSIQ across ethnic and gender groups

This study examines differential prediction of WIAT achievement scores based on WISC-III FSIQ in white as compared with African American and Hispanic children, and in females as compared with males. A procedure which allows simultaneous comparisons of slopes and intercepts across groups is employed. The results are consistent with previous research findings in supporting the general absence of bias in predicting achievement from IQ.     

Socialization influences of collegiate female athletes: A tale of two decades

Over the past decade, sport participation opportunities for females have increased dramatically. The purposes of this study were to compare perceptions of encouragement and support from socializing agents for: (a) female collegiate volleyball players competing during the 1979 and 1989 seasons, and (b) female collegiate athletes and female and male nonathletes. Female athletes (n= 345), female nonathletes (n= 128), and male nonathletes (n= 88) completed a questionnaire to assess significant others' influence on sport involvement during childhood, adolescence, and college years. Results indicated that interest and encouragement by parents, older siblings, and friends significantly increased for female athletes over the past 10 years during one or more developmental period. Discriminant analyses revealed that female athletes perceived stronger influences from mother, siblings, friends, and coaches than did male and female nonathletes. These results demonstrate that female athletes received greater social support than their peers a decade earlier, and these influences were significantly different than male and female nonathletes. This study was supported by a grant awarded to the first author by the Center for the Study of Women in Society, University of Oregon, Eugene.