Isolating the typicality effect in semantic memory

An experiment was conducted to isolate the typicality effect in the overall categorization process. Subjects were required to indicate whether or not a probe word was a member of one of a variable number of categories held in memory. The typicality of the probe word, with respect to its superordinate category, was varied as was the physical quality of the probe. These manipulations were designed to test predictions drawn from Collins and Loftus (1975) and Anderson and Reder (1974), as well as a prediction based on the well-known effect of semantic context on word perception. A fourth prediction was drawn from a proposed model which postulates successive access of categories and locates the typicality effect in a within-category search stage. Typicality proved to be additive with stimulus quality and set size, but interacted with response type. These results were interpreted as support for the successive-access within-category search model while disconfirming the alternative predictions.     

Ethical issues in diagnosis

The ways in which ethical issues arise in making clinical judgments are briefly discussed. By showing the topography of the role of value judgments in medical diagnostics it is suggested why clinical medicine remains inextricably a value-infected science.     

Local contrast and maintained generalization.

Pigeons received variable-interval reinforcement for key pecking during presentations of horizontal and vertical line-orientation stimuli, while pecks during five intermediate orientations were extinguished. Lowest peck rates were observed during presentations of negative stimuli adjacent to the positive orientations while peck rate during 45 degrees (the intermediate negative orientation) was relatively high, i.e., there were negative contrast shoulders. When peck rates were manipulated in the positive orientations, peck rate in neithboring orientations changed in the opposite direction. Contrast shoulders faded after prolonged training. A second type of contrast, local contrast, was correlated with similarity of preceding stimulus and different average peck rates during different stages of the discrimination process. The data suggest that sequential local contrast accompanying the formation of a discrimination contributes to the form of generalization gradients. Blough's model of stimulus control predicts the changes in gradient form described here, but may not accurately depict the underlying process responsible for gradient form.     

Time-series analysis of long-term cardiovascular response

The purpose of this study was to illustrate the use of time-series analysis with long-term cardiovascular responding. Analyses of two successive 1000-minute mean blood pressure and heart-rate series in five chronically instrumented dogs showed that the autocorrelation function of the original series appeared highly nonstationary and that differencing the data produced a simple autocorrelation pattern which could be successfully modeled with stepwise autoregression. Evidence for reliable individual differences as well as change over sessions is presented and discussed.     

The self-serving function of hypochondriacal complaints: physical symptoms as self-handicapping strategies

The present experiment tested the hypothesis that hypochondriacal individuals commonly use reports of physical illness and symptoms as a strategy to control attributions made about their performances in evaluative settings (i.e., self-handicapping strategies). Specifically, it was predicted that hypochondriacal individuals would report more recent physical illness and complaints and more current physical symptoms in an evaluative setting in which poor health could serve as an alternative explanation for poor performance than would either individuals in an evaluative setting in which poor health was precluded as an excuse or individuals in a nonevaluative setting. As predicted, results supported this self-protective pattern of complaints in a hypochondriacal sample but not in a nonhypochondriacal group. The self-protective role of hypochondriacal behavior is discussed in relation to other theory and research on the nature and treatment of hypochondriasis.