The influence of object-image velocity change on perceived heading in minimal environments

When human observers move forward and rotate their eyes, a complex pattern of light flows across the retina. This pattern is referred to as retinal flow. A model has been proposed to explain how humans perceive their direction of self-movement (or heading) from (1) static depth, (2) direction of image motion, and (3) whether image velocity undergoes acceleration or deceleration (Wang & Cutting, 1999). However, findings from past research in which sparse or minimalist stimuli were used have suggested that not all of the information to which participants are sensitive is captured within the scope of this model. In particular it has been suggested that the magnitude or size of image velocity change may be of significance beyond simply whether image velocity could be categorized as speeding up (i.e., accelerating) or slowing down (i.e., decelerating). In two experiments, the influence of this factor on heading judgments under minimal conditions was investigated. Evidence was found in support of the idea that the rate of image velocity change can influence judgments of the direction of self-movement in minimalist conditions.     

Psychopathological correlates of contextualized images in dreams

A contextualized image is a powerful central image in a dream which provides a picture context for the dominant emotion of the dreamer. This study examined the psychopathological correlates of both dream and nightmare contextualized images in a community-based sample of 378. As predicted, mean nightmare contextualized image scores were significantly higher than mean dream scores. In addition, while dream contextualized images were unrelated to psychopathology, nightmare contextualized images were significantly associated with elevated scores on three SCL-90-R subscales and the General Symptom Distress Index.     

Perceptions of the importance of training,experience, and athletic talent for achievement in sports

Ratings by 97 NCAA Division I athletes showed belief that successful athletes benefit more from training and experience and athletic talent than less successful athletes.     

Fostering group identification and creativity in diverse groups: the role of individuation and self-verification

A longitudinal study examined the interplay of identity negotiation processes and diversity in small groups of master's of business administration (MBA) students. When perceivers formed relatively positive impressions of other group members, higher diversity predicted more individuation of targets. When perceivers formed relatively neutral impressions of other group members, however, higher diversity predicted less individuation of targets. Individuation at the outset of the semester predicted self-verification effects several weeks later, and self-verification, in turn, predicted group identification and creative task performance. The authors conclude that contrary to self-categorization theory, fostering individuation and self-verification in diverse groups may maximize group identification and productivity.     

Visual discrimination of number without counting

Observers in this study judged which of two fields contained the greater number of spots. Spots had difference-of-Gaussian luminance profiles and could differ in contrast polarity or were of uniform luminance and could differ in size. Weber fractions for all observers except one varied little except when spots varied in size. It is suggested that the results of this and previous studies might be explained by the existence of neurons tuned for number.     

The Ethics of Type 1 Diabetes Prediction and Prevention Research

There are approximately one million cases oftype 1 diabetes in the US, and the incidenceis increasing worldwide. Given that two-thirdsof cases present in childhood, it is criticalthat prediction and prevention research involvechildren. In this article, I examine whethercurrent research methodologies conform to theethical guidelines enumerated by the NationalCommission for the Protection of Human Subjectsof Biomedical and Behavioral Research, andadopted into the federal regulations thatprotect research subjects. I then offer twopolicy recommendations to help researchersdesign studies that conform to these ethicalrequirements.     

Representing tools: how two non-human primate species distinguish between the functionally relevant and irrelevant features of a tool

Few studies have examined whether non-human tool-users understand the properties that are relevant for a tool's function. We tested cotton-top tamarins (Saguinus oedipus) and rhesus macaques (Macaca mulatta) on an expectancy violation procedure designed to assess whether these species make distinctions between the functionally relevant and irrelevant features of a tool. Subjects watched an experimenter use a tool to push a grape down a ramp, and then were presented with different displays in which the features of the original tool (shape, color, orientation) were selectively varied. Results indicated that both species looked longer when a newly shaped stick acted on the grape than when a newly colored stick performed the same action, suggesting that both species perceive shape as a more salient transformation than color. In contrast, tamarins, but not rhesus, attended to changes in the tool's orientation. We propose that some non-human primates begin with a predisposition to attend to a tool's shape and, with sufficient experience, develop a more sophisticated understanding of the features that are functionally relevant to tools.     

The Metaethical Paradox of Just War Theory

The traditional requirements upon the waging of a just war are ostensibly independent, but in actual practice each tenet is subject ultimately to the interpretation of a legitimate authority, whose declaration becomes the necessary and sufficient condition. While just war theory presupposes that some acts are absolutely wrong, it also implies that the killing of innocents can be rendered permissible through human decree. Nations are conventionally delimited, and leaders are conventionally appointed. Any group of people could band together to form a nation, and any person could, in principle, be appointed the leader of any nation. Because the just war approach assumes absolutism while implying relativism, the stance is paradoxical and hence rationally untenable.