Categorical processing of visual stimuli in relation to geometrical,graphemic, or lexical context

Summary Categorical perception was first demonstrated in studies of speech sounds (Liberman, Harris, Hoffman, & Griffith, 1957). The present work employed visual stimuli to explore categorical responding in relation to the context in which the stimuli were embedded. The target stimulus was a vertical line whose length was varied from 20 to 31 min (approximately) in steps of 1.2 min. Experiment 1 examined the effect of a geometrical context on the subjects' ability to discriminate between pairs of lines. The context improved performance, but produced no evidence of categorical responding. In Experiment 2 a graphemic context depressed performance, but failed to show clear evidence of categorization. By contrast, strong evidence of categorical responding was obtained in Experiment 3, in which the graphemes used in Experiment 2 were embedded in meaningful words. From this pattern of results it is argued that categorical responding is reflective not of relatively peripheral perceptual activity, but of higher-order decision processes.     

The necessary a posteriori: A response to Tichý

Conclusion Some of Tichý's conclusions rest on an assumption about substitutivity which Kripke would not accept. If we grant the assumption, then Tichý successfully shows that we can discover true identity statements involving names a priori, but not that we can discover a priori what properties things have essentially. Many of Tichý's arguments require an implausible rejection of the possibility of indirect belief as described in Section III. 25Are there necessary a posteriori propositions? I have argued that we certainly can discover necessary propositions a posteriori, but have left it an open question whether there are necessary propositions which we can only discover a posteriori.What effect do the considerations here presented have on the positivist doctrine that the a priori and the necessary coincide? My explanation of how we discover necessary propositions a posteriori involves our believing them indirectly, in virtue of believing contingent propositions. I would argue that Kripke's examples of the contingent a priori involve, similarly, our believing the contingent propositions in directly, in virtue of believing necessary propositions.This suggests that a reformulation of the positivist thesis along something like the following lines may well be correct. Let us say that someone directly believes a proposition just in case he could not fail to believe it without being in a different cognitive state. Then perhaps one can directly believe a proposition on the basis of a priori evidence only if it is necessary, and can directly believe a proposition on the basis of a posteriori evidence only if it is contingent.     

Ordinal properties of subjective ratios and differences: Comment on Veit

Because nonmetric analyses of judged ratios and differences in sensory magnitude have yielded similar scales, some investigators have concluded that a single perceived relation underlies both judgment tasks. Issues rasied by this interpretation are considered in this article. Simulated data based on the assumption that subjects evaluate both perceived relations were computed for stimulus values used by Veit to investigate judgments of ratios and differences in grayness. A nonmetric analysis of both sets of simulated data in terms of a difference model yielded a solution such that each set of data was a weak monotonic transformation of the model's values, and the scale values were approximately linear with those obtained by Veit from empirical data. This result leaves open the question of whether one or two perceived relations underly the data. Ordinal properties of ratios and differences for a finite set are discussed together with their relation to systematic biases in psychophysical judgment tasks.     

Effect of noise distractibility on the spans of apprehension of hyperactive boys

Denton and McIntyre (1978), using a forced-choice letterrecognition procedure, demonstrated increasing reductions in the spans of apprehension of hyperactive as compared to normal boys when a signal letter was embedded within an increasing number of noise letters. In the present study, the effect of variations in the amount of physical signal-noise similarity and noise redundancy upon the spans of apprehension of hyperactive and normal boys was compared to determine whether noise letters act as more potent distractors for the hyperactive boys. Results indicated the spans of both groups were effected equivalently by variations in signal-noise similarity and noise redundancy. No evidence for a distractibility explanation was obtained.     

Educating both halves of the brain: Educational breakthrough or neuromythology?

The increasing popularity of the idea that the two hemispheres of the human cerebral cortex carry on different modes of thinking has resulted in an accelerating social and commercial pressure to organize school curricula, teaching, and testing to conform to a right brain-left brain dichotomy. Evidence gathered from commissurotomy (split-brain) patients and right hemisphere studies on normal intact humans is reviewed and evaluated. Conclusions from this review are (a) the commissurotomy patients are not a suitable group on which to base generalizations about cortical functioning in the normal intact human; (b) the right-left hemisphere differences reported in many experiments on normal subjects are small and can be found only in an extremely narrow experimental context; and (c) there is no scientific basis in this work for any reorganization of curricular, teaching, or testing programs within contemporary educational practice.     

From innocence to experience: Teaching medical ethics to medical students

The author describes the content and method of a course in medical ethics for second-year medical students. He discusses the clergyperson's role in teaching medical ethics in relationship to physicians and concludes with reflections upon the study of medical ethics as part of the rite of passage of medical education.     

Organizational Moral Identity Centrality: Relationships with Citizenship Behaviors and Unethical Prosocial Behaviors

This article examines the influence of both individual and organizational moral identity centrality on prosocial behaviors. Furthermore, we hypothesize that the centrality of these two offer a substitute effect on these behavioral outcomes. Validated measures of organizational moral identity centrality and unethical prosocial behavior are introduced. Data were collected via two separate samples, University Greek Life organization members (n = 499) and restaurant workers (n = 137). Regression results supporting that individuals who claim centrality of moral identity and see their organizations to also embrace the centrality are more likely to engage in citizenship behaviors and less likely to commit unethical prosocial acts. Furthermore, results support that both forms of centrality of moral identity were substitutes in terms of affecting these two outcomes. Research that contributes to understanding how individuals within an organization consciously choose to act on behalf of the organization even when these very actions conflict with generally accepted morals of right and wrong within their society is valuable to academics and practitioners alike. This study contributes to this body of knowledge. Despite extensive attention to topics of ethics and identity, previous studies have largely overlooked the impact of an organizational moral identity. Our results provide a framework for understanding the role of moral identity and the prediction of organizational citizenship and unethical prosocial behaviors.