Influence of temporal masking on click-pair discriminability

When temporal auditory acuity is estimated using time-reversed click pairs, the asymmetry of temporal masking may influence the results. To investigate this hypothesis, we first established normal-hearing listeners’ psychometric functions for the discrimination of time-reversed click pairs. An attempt to relate listeners’ performances in click-pair discrimination to their performances in forward and backward masking tasks was unsuccessful, probably due to the presence of spectral artifact in the temporal masking paradigms. We then investigated listeners’ abilities to discriminate time-reversed click pairs in which the intensity of the lower level click in one pair was altered. This alteration was introduced at random in order to minimize the influence of spectral artifact. Our results suggest that the course of temporal masking influenced the discriminability of the modified click pairs. Thus, the discrimination of time-reversed click pairs may yield a biased estimate of auditory temporal acuity.     

The Cost-Reward Model of Helping Behavior: A Nonconfirmation1

A field experiment was designed to test several predictions derived from the Piliavin and Piliavin cost-reward model of helping behavior. Female and male subjects' reported intent to help a hemophiliac in a nearby hospital was unrelated to the costs for helping, the costs for not helping, and the order in which the subjects received the costs' manipulations. The obtained rates of helping were also unrelated to whether or not subjects reported having donated previously. Failure to obtain the predicted results is discussed.     

Normative location theory: Placement in continuous space

This paper selectively reviews an area of operations research, refered to as normative location theory, that deals with the placement of objects in continuous space. The computational procedures discussed in this literature require initially that a certain set objects be located a priori; the placement of the objects in a second set is then determined in such a way that the total “interaction” among the fixed and variable objects is minimized. A number of strategies appropriate for different distance functions are surveyed and a numerical example is given illustrating one particular iterative algorithm. Although the current versions of these location methods depend upon more than the nonmetric information contained in the proximity measures defined for all pairs of objects, they can be generalized, and consequently, several possible connections to nonmetric multidimensional scaling are pointed out.     

Effects of schedule and magnitude of reinforcement under conditions of thirst motivation

In contrast to a recent finding (Macdonald, G. E., & De Toledo, L. Learning and Motivation, 1974, 5, 288–298.) the results of three experiments investigating various partial reinforcement (PRF) manipulations under conditions of thirst motivation demonstrated strong similarity to analogous manipulations involving food reward. Specifically, for animals receiving water reinforcement, PRF was shown to generate greater resistance to extinction than continuous reinforcement (Expt 1 & 3), the schedule of reinforcement was shown to interact with level of acquisition (Expt 1 and 2), and the magnitude of the partial reinforcement extinction effect was shown to be a function of reward magnitude (Expt 3). These results provide strong evidence that mechanisms which operate in partial reinforcement situations are highly similar, regardless of the type of appetitive reinforcement.     

Sex-related effects on clinicians' attributions of parental responsibility for child psychopathology

An attempt was made to reproduce and extend previously reported data suggesting the operation of sex-related bias in clinicians' attributions of parental involvement in children's psychopathologies. More and less sex-role traditional male and female family-oriented practitioners were shown contrived profiles in which a boy or girl was described as masculine or feminine role-deficient, and apportioned maternal versus paternal blame, treatment focus, adjunctive therapy need, and likelihood of sabotage. As in the previous study, mothers were implicated slightly more than fathers and also were viewed as requiring relatively greater therapeutic attention by female than by male clinicians. However, several earlier findings were not replicated. Overall, the results offer only marginal support for the notion of sex-related practitioner bias.     

The psychophysiology of combat-induced post-traumatic stress disorder in Vietnam veterans

The psychophysiological responses of heart rate (HR), systolic and diastolic blood pressure, skin conductance level and forehead electromyogram were compared during: rest, mental arithmetic and combat sounds of gradually increasing intensity for five groups of Ss: Vietnam veterans with post-traumatic stress disorder (PTSD); Vietnam veterans without PTSD but with comparable levels of combat experience; Vietnam veterans with other psychiatric disorders; Vietnam-era veterans; and nonveteran phobics. HR response to low-intensity combat sounds provided good discrimination between veterans with PTSD and the other groups and seems to resemble a conditioned emotional response.