Can the monster Errour be slain?

One cannot discount experimental errors and turn the attention to the logicomathematical structure of a physical theory without distorting the nature of the scientific method. The occurrence of errors in experiments constitutes an inherent feature of the attempt to test theories in the physical world. This feature deserves proper attention which has been neglected. An attempt is made to address this problem.     

Drawing Movements as an Outcome of the Principle of Least Action

According to the two-thirds power law the cube of the speed of a drawing movement is proportional to the radius of curvature of the trajectory, and the coefficient of proportionality has the meaning of mechanical power. We derive this empirical law from the variational principle known in physics as the principle of least action. It states that if a movement between two points of a given path obeys the two-thirds law, then the amount of work required to execute a trajectory in a fixed time is minimal. In this strict sense one may say that among infinitely many ways to execute a given path, the central nervous system chooses the most economical. We show that the kinematic equations for all drawing movements are solutions of a certain differential equation with a single (time-variable) coefficient. We consider several special cases of drawing movements corresponding to simplest forms of this coefficient. Copyright 2001 Academic Press.     

Social support from friends predicts changes in memory specificity following a stressful life event

ABSTRACT

Exposure to negative life stress has been associated with difficulty retrieving memories for specific autobiographical events, with important consequences for the emergence of emotional disorders. We examined whether social support can protect against the effects of negative events on memory specificity. University students (N?=?143) were assigned to groups based on whether or not they experienced a negative stressor, operationalised as whether or not their recent exam performance was in line with their expectations. After receiving their exam results (T1), and one month later (T2), participants completed measures of memory specificity, their attitudes towards themselves and the occurrence of other stress-related events. Participants also completed a general measure of perceived social support from friends, family, and significant others, and an equivalent measure for social support related to performance. For participants who experienced an exam-related stressor, reduced performance-specific social support from friends was associated with reduced memory specificity at T2, even when accounting for T1 memory specificity, individual differences in attitudes towards self, the experience of additional stressors, and gender. No such relation was present for participants who did not experience a stressor. These findings provide new understanding of the influence of social variables on autobiographical memory specificity.     

Proactive Personality and Employee Creativity: The Effects of Job Creativity Requirement and Supervisor Support for Creativity

This study examined the relationships between proactive personality and employee creativity and the moderating roles of job creativity requirement and supervisor support for creativity in activating proactive personality associated with employee creativity. To provide a rigorous test of the hypotheses, we conducted a field study from a sample of 157 employee–supervisor pairs in South Korea. The results revealed that a proactive personality was positively associated with employee creativity. In addition, job creativity requirement and supervisor support for creativity jointly influenced the relationship between proactive personality and employee creativity. Specifically, proactive employees exhibited the highest employee creativity when job creativity requirement and supervisor support for creativity were both high.     

Rare targets are less susceptible to attention capture once detection has begun

Rare or low probability targets are detected more slowly and/ or less accurately than higher probability counterparts. Various proposals have implicated perceptual and response-based processes in this deficit. Recent evidence, however, suggests that it is attentional in nature, with low probability targets requiring more attentional resources than high probability ones to detect. This difference in attentional requirements, in turn, suggests the possibility that low and high probability targets may have different susceptibilities to attention capture, which is also known to be resource-dependent. Supporting this hypothesis, we found that, once attentional resources have begun to be engaged by detection processes, low, but not high, probability targets have a reduced susceptibility to capture. Our findings speak to several issues. First, they indicate that the likelihood of attention capture occurring when a given task-relevant stimulus is being processed is dependent, to some extent, on how said stimulus is represented within mental task sets. Second, they provide added support for the idea that the behavioural deficit associated with low probability targets is attention-based. Finally, the current data point to reduced top-down biasing of target templates as a likely mechanism underlying the attentional locus of the deficit in question.     

Koffka's effect is mediated by figure thickness at the joining region

Three-quarters of a century ago Gestalt psychologist Kurt Koffka described a remarkable effect: when a contiguous gray ring is placed on a background half one shade of gray, half another, the ring appears homogeneous. However, if the ring is divided, the two halves of the ring appear different shades of gray, the half of the ring on the darker background appearing lighter than the half of the ring on the lighter background. The Gestalt principle of continuity is used to explain this effect. But what microscopic principles might be mediating this effect? Recently we found sufficiently thin rings (annuli) appear heterogeneous even when geometrically continuous. Here, using crescent-shaped figures instead of the circular annuli used for the traditional Koffka effect, we show that this effect of thickness of the ring is mediated by the thickness at the boundary of the region where the halves of the figure are joined.     

Metameric intransitivity

There are two kinds of afterimages. In negative afterimages, looking at a blank field after staring at a colored figure gives a figure whose color is complementary to that of the original figure. Less well understood and studied is the phenomenon of induced positive afterimages, in which staring at a colored area surrounding a small white test patch produces an afterimage in which the hue of the surround is transferred into the previously white area. Using these differences between positive and negative afterimages and also simultaneous color contrast, which has an effect on a test patch different from either of the afterimage effects, we describe a new effect, metameric intransitivity, in which perceptually similar images can generate markedly different afterimages, whereas perceptually different images can generate indistinguishable afterimages. Supplemental figures depicting the stimuli, results, and method for generating the intransitive metamers in this study may be downloaded from http://app.psychonomic-journals.org/content/supplemental.     

Thickness and the Koffka ring effect

Over seven decades ago Gestalt psychologist Kurt Koffka described a remarkable effect: when a contiguous gray ring is placed on a background half of one shade of gray, half of another, the ring appears homogeneous. However, if the ring is slightly divided, the two halves of the ring appear different shades of gray, the half of the ring on the darker background appearing lighter than the half of the ring on the lighter background. The Gestalt principle of continuity is used to explain this effect. We show that when the ring is made thinner it appears heterogeneous even when contiguous. We also illustrate this in the additional material with a colored background with more than two regions.