A simple and inexpensive click-free audio switch

This paper describes a click-free audio switch that functions by controlling the rate of onset and decay of a signal. The principle component of the switch is a device whose resistance is a function of the light intensity falling upon it. Circuit diagrams and suggested applications are provided.     

Perceptual separability and spatial models

Highly analyzable two-dimensional color stimuli were generated using stimulus cards such that one part of each card varied only on the first dimension and the other part varied only on the second. Subjects were required to make judgments of similarity between pairs of these analyzable stimuli, between pairs of relatively unanalyzable color stimuli, and between pairs of geometric stimuli. The results support previous findings that the Euclidean combining rule is appropriate for judgments of single color patches but indicate that the city block combining rule may be appropriate for simple stimuli that vary on perceptually distinct dimensions.     

Punishment shock intensity and basal skin resistance

The relationship between punishment shock intensity and basal skin resistance (BSR) was investigated in two sessions with human females selected for their ability to maintain a fairly substantial operant rate under a wide range of shock intensities. In both sessions each button-pressing response was reinforced with a counter tally. Subjects were paid one cent for each 20 counts. In session 1, punishment followed each response during alternate 4-min periods; in session 2 punishment was programmed in all 4-min periods. Shock intensities were presented randomly among the 4-min shock periods, with the restriction that the first three presentations occurred in ascending order. Operant responding showed some suppression at higher shock intensities in session 1, with substantial recovery in most subjects during session 2. Respondent behavior was characterized by greater activity at successively higher intensities, with recovery at all shock levels, especially the lowest levels, apparent during the second session.     

Effects of chlorpromazine on lateralization, cued reaction time, and dichotic listening

In a double-blind cross-over design sixteen subjects took 50 mg of chlorpromazine or placebo in tablet form 2 hours prior to completing a dichotic listening and simple reaction time task with and without warnings. In the simple reaction time task, blocks of 80 stimuli were presented to each ear with and without warning cue under drug and placebo conditions. On the dichotic listening task the expected right ear advantage for reporting digits was obtained. While the drug had no main effect on the number of errors, there were more trials on which an ear advantage was present than in the placebo condition. In the reaction time task there were main effects of drug, warning cue and foreperiod: warnings facilitated reaction; chlorpromazine retarded reaction; and reaction times were most facilitated by warning foreperiods in excess of 1200ms. Several findings were of interest: On uncued trials, with placebo, right ear responses were faster than those for stimuli presented to the left ear. Drug also interacted with foreperiod duration. These results were interpreted in the light of Tucker and Williamson’s (1984) review of the role of Pribram and McGuinness’s Arousal and Activation sytems in lateralized behavior.     

Understanding the effects of sample size on the variability of the mean

In the first three experiments, we attempted to learn more about subjects' understanding of the importance of sample size by systematically changing aspects of the problems we gave to subjects. In a fourth study, understanding of the effects of sample size was tested as subjects went through a computerassisted training procedure that dealt with random sampling and the sampling distribution of the mean. Subjects used sample size information more appropriately for problems that were stated in terms of the accuracy of the sample average or the center of the sampling distribution than for problems stated in terms of the tails of the sampling distribution. Apparently, people understand that the means of larger samples are more likely to resemble the population mean but not the implications of this fact for the variability of the mean. The fourth experiment showed that although instruction about the sampling distribution of the mean led to better understanding of the effects of sample size, subjects were still unable to make correct inferences about the variability of the mean. The appreciation that people have for some aspects of the law of large numbers does not seem to result from an in-depth understanding of the relation between sample size and variability.     

Gender differences in the relation between stressful life events and adjustment among school-aged children

The study evaluated gender differences in the relation between stressful life events and adjustment among elementary school children. In Study I, anxiety, aggression, submissive withdrawal, and life event questionnaires were completed by 63 Israeli children. The frequency of life events was associated with increased anxiety and trends toward heightened withdrawal and aggression among boys, but not girls. In Study II, 80 Israeli mothers of elementary school children completed parallel questionnaires regarding their child. As in Study I, life events were associated among boys, but not girls, with increased anxiety and a trend toward heightened withdrawal. No gender difference arose in the association for aggression. Discussion focused on the possible roots of these findings in differential patterns of stress sensitivity, resilience, and coping, and on their ramifications for the study of cross-situational gender differences.     

Orientation asymmetry in the flanker task

Experiments 1 and 2 of this study show that when the target is either a vertical or a horizontal line, diagonal-line flankers tilted 45° either to the right or to the left have the same effect as do incongruent flankers. When the target is a diagonal line tilted either to the right or to the left, vertical- or horizontal-line flankers do not have the same effect as do incongruent flankers. Experiment 3 demonstrates that this asymmetry is not caused by the temporal-dynamic aspects of the processing. Together, these experiments suggest that there is an asymmetrical relation between diagonal lines and either vertical or horizontal lines otttside of the central focus of attention. Experiment 4 shows that despite this asymmetry in the flanker task, visual search for a vertical- or a horizontal-line target among diagonal-line distractors is not affected by the number of distractors. Possible explanations of this phenomenon are discussed.     

Contributions of empirical research to medical ethics

Empirical research pertaining to cardiopulmonary resuscitation (CPR), clinician behaviors related to do-not-resuscitate (DNR) orders and substituted judgment suggests potential contributions to medical ethics. Research quantifying the likelihood of surviving CPR points to the need for further philosophical analysis of the limitations of the patient autonomy in decision making, the nature and definition of medical futility, and the relationship between futility and professional standards. Research on DNR orders has identified barriers to the goal of patient involvement in these life and death discussions. The initial data on surrogate decision making also points to the need for a reexamination of the moral basis for substituted judgment, the moral authority of proxy decision making and the second-order status of the best interests standard. These examples of empirical research suggest that an interplay between empirical research, ethical analysis and policy development may represent a new form of interdisciplinary scholarship to improve clinical medicine.     

PARENT EDUCATION PROJECT III: INCREASING AFFECTION AND RESPONSIVITY IN DEVELOPMENTALLY HANDICAPPED MOTHERS: COMPONENT ANALYSIS,GENERALIZATION, AND EFFECTS ON CHILD LANGUAGE

We evaluated the effects of a parent training program consisting of verbal instruction, modeling, and feedback on the affection and responsivity of 3 developmentally handicapped mothers towards their children. The results indicated the following: First, the training package increased maternal physical affection, praise, and imitation of child vocalizations. These parenting skills increased to levels found in comparison groups of nonhandicapped mothers. Second, the training package was more effective than verbal instruction alone, the latter being the predominant method presently used by social service workers. Third, most maternal gains were maintained over a 3- to 18-month follow-up period, although one mother required a reinforced maintenance procedure. Fourth, instructing mothers to generalize served to increase the generalization of newly acquired skills from play times (the training context) to child-care tasks (e.g., diapering, feeding). Fifth, teaching the parents to imitate child vocalizations was related to gains in both the frequency and quality of verbal behavior of the two language delayed children as measured by standardized developmental tests and in vivo comparisons with age-matched children (who had nonhandicapped parents). These results show that behavioral instruction can improve important child-rearing skills of developmentally handicapped mothers, with corresponding benefits to their children.