Predatory aggression: Midbrain-pontine junction rather than hypothalamus as the critical structure?

Electrical stimulation of sites in the region of the ventromedial periaqueductal gray substance at the level of the midbrain–pontine junction was found to elicit a predatory attack by a cat upon a rat. The intensity of stimulation required to elicit the attack was three to four times less than that required to elicit similar behavior by hypothalamic stimulation. The results suggest that anatomically distinct regions of the periaqueductal gray substance are concerned with the regulation of predatory and affective forms of aggressive behavior. The difficulty in reconciling these results with the preeminent role assigned the hypothalamus in the organization of predatory behavior is also discussed.     

ELEVATION OF VOICE VOLUME IN YOUNG DEVELOPMENT ALLY DELAYED CHILDREN VIA AN OPERANT SHAPING PROCEDURE

Unusually low voice volume was identified by teachers as a significant impediment to the academic and social progress of two preschool students. A simple operant shaping procedure was conducted by teachers to increase voice volume using a voice-activated apparatus with attractive visual display. Setting generalization of volume increases to the classroom was achieved and maintained at one- and four-month follow-ups.     

Oral self-administration of pentobarbital by rhesus monkeys: maintenance of behavior by different concurrently available volumes of drug solution.

For 4 rhesus monkeys, mouth-contact responses with either of two brass spouts were reinforced according to fixed-ratio schedules by 0.65-mL liquid deliveries during daily 3-hr sessions. Three experiments were conducted. In each experiment, independent fixed-ratio schedules were concurrently in effect at the two spouts. Following completion of each fixed ratio on a spout, a specified number of liquid deliveries were available from that spout under a continuous-reinforcement schedule. The number of such deliveries available at each spout was manipulated independently. In Experiment 1, a 1-mg/mL pentobarbital solution was simultaneously available with water (the drug vehicle) under concurrent fixed-ratio schedules of 32 responses for 3 subjects and 64 responses for the remaining subject. The number (N) of liquid deliveries that were available after completion of each fixed ratio was varied in the following order: 8, 4, 2, 1, and 8 (retest). For each subject at each condition, drug maintained more responding than water. The number of drug deliveries obtained per session was directly related to the amount of drug available per fixed ratio (i.e., to N), whereas the number of fixed ratios completed per session generally was inversely related to the value of N. In Experiment 2, fixed-ratio size was the same for each subject as in Experiment 1, but deliveries of a 1-mg/mL pentobarbital solution were available at both spouts. The number of drug deliveries available under one fixed-ratio schedule (Ns, the "standard" reinforcer amount) was held at eight, and the number of drug deliveries available under the second schedule (Nc, the "comparison" reinforcer amount) was changed across blocks of six sessions of stable responding in the following order: 1, 2, 4, 8, 4, 2, and 1. The identical series of comparison reinforcer amounts (Nc) was then tested twice more, but with the standard reinforcer (Ns) held first at four and then at two deliveries. Across the three choice series, reinforcing effects were directly related to reinforcer magnitude. In Experiment 3, deliveries of a 1-mg/mL pentobarbital solution again were available at both spouts. However, the two reinforcer amounts were held constant at N = 8 deliveries under one schedule and N = 4 deliveries under the second schedule, and fixed-ratio size was systematically varied. Across the range of fixed-ratio sizes from low to high, the degree to which behavior was better maintained by the larger of the two drug quantities was an inverted U-shaped function of fixed-ratio size.(ABSTRACT TRUNCATED AT 400 WORDS)     

非言语学习不良的研究现状和展望

非言语学习不良日益成为学习不良研究的新热点,非言语学习不良的概念界定、筛查和诊断标准以及非言语学习不良的神经心理、认知、社会性和教育干预等领域取得了大量的研究成果。但是,非言语学习不良研究中还存在许多需要解决的问题,如：界定标准不统一;对非言语学习不良的系统研究有待完善;缺乏有效的干预模式及实证研究等。这些问题都需要进一步的研究、探讨     

White Matter Hyperintensities and Working Memory: An Explorative Study

ABSTRACT

White matter hyperintensities (WMH) are commonly observed in elderly people and may have the most profound effect on executive functions, including working memory. Surprisingly, the Digit Span backward, a frequently employed working memory task, reveals no association with WMH. In the present study, it was investigated whether more detailed analyses of WMH variables and study sample selection are important when establishing a possible relationship between the Digit Span backward and WMH. To accomplish this, the Digit Span backward and additional working memory tests, WMH subscores, and cardiovascular risk factors were examined. The results revealed that performance on the Digit Span backward test is unrelated to WMH, whereas a relationship between other working memory tests and WMH was confirmed. Furthermore, a division between several white matter regions seems important; hyperintensities in the frontal deep white matter regions were the strongest predictor of working memory performance.     

The rise of information in an evolutionary universe

This paper outlines the grand scenario of cosmic evolution by examining the ongoing changes among radiation, matter and life in standard, big‐bang cosmology. Using aspects of non‐equilibrium thermodynamics and information science, we argue that it is the contrasting temporal behavior of various energy densities that have given rise to the environments needed for the emergence of galaxies, stars, planets, and life forms. We furthermore argue that a necessary (though perhaps not sufficient) condition—a veritable prime mover—for the emergence of such ordered structures of growing complexity is the expansion of the Universe itself. Neither demon‐strably new science nor appeals to non‐science are needed to explain the impressive hierarchy of developmental change, from quark to quasar, from microbe to mind.     

On the Escaig obstacle hypothesis for cross-slip in face-centered-cubic materials

There is a significant body of literature wherein a linear approximation of Escaig's model is used to justify the large experimentally measured activation-volumes for cross-slip in face-centered-cubic copper. Here, by examining the error between the linear approximation and the original theory, we show that this explanation is not satisfactory. The calculated value for activation volume in copper, using Escaig's original equations, yields ～60b ³ (b?=?Burgers vector) while the linear approximation yields 200b ³, the latter result fortuitously matching the experimental values.     

THE “GHOSTS” OF IRAS PAST AND THE CHANGING CULTURAL CONTEXT OF RELIGION AND SCIENCE

Beginning with our cosmic ancestors and the 1950s ancestors of Institute on Religion in an Age of Science (IRAS, the “Ghosts”), this essay highlights the wider, post‐World War II cultural context, including other science and religion organizations, in which IRAS was formed. It then considers eight challenges from today's context. From the context of science there are (1) the challenge of scale that leads us to question our place in the scheme of things and can lead to a challenge to morale concerning whether we make any difference; (2) the challenge of human variability that leads to the question whether there is a single human moral nature; and (3) the challenge of detailed explanation that leads to the question of what is the task of theology in relation to detailed scientific explanation. From the religion context there are (4) the challenge of objectivity—studying religion without practicing religion; and (5) the challenge of pluralism and the variety of cultural and religious perspectives. From the context of the growing and diverse science‐and‐religion enterprise, considered from the perspective of IRAS developed in the first part of this essay, there are the challenges of (6) apologetics and (7) intellectualization. Finally, from the context of our growing, worldwide consumerist culture that is contributing to the radical alteration of the planetary environment, leading to much suffering, there is (8) the challenge of becoming more motivated to act for the long‐term global good.     

Assessing the role of spatial engagement and disengagement of attention in anxiety-linked attentional bias: a critique of current paradigms and suggestions for future research directions

A considerable volume of research has demonstrated an anxiety-linked attentional bias characterized by selective processing of threat stimuli. The last decade has seen growing interest in identifying the precise attentional mechanisms which underlie such selective processing to advance both theoretical and etiological models of anxiety. This research has particularly focused on the roles of spatial engagement and disengagement of attention. The relative contribution of these attentional components to selective processing of threat in anxious individuals remains unclear however. Moreover, we argue here that many of the tasks employed to examine these mechanisms, may not be capable of indexing the attentional processes that they claim to measure. In this article, we provide a methodological review, critically evaluating the adequacy of previous tasks employed to measure biased attentional engagement and disengagement. Based on a number of concerns raised about the ability of such tasks to differentiate these component attentional processes, we detail three task criteria that we believe are essential to be confident that a task will accurately index biased attentional engagement with, and disengagement from threat in anxious participants.     

Microstructural integrity of the corpus callosum linked with neuropsychological performance in adolescents

Background: Diffusion tensor imaging (DTI) has revealed microstructural aspects of adolescent brain development, the cognitive correlates of which remain relatively uncharacterized. Methods: DTI was used to assess white matter microstructure in 18 typically developing adolescents (ages 16–18). Fractional anisotropy (FA) and mean diffusion (MD) were evaluated within the splenium and body of the corpus callosum in relation to cognitive performance. Results: Visuospatial construction abilities were associated with white matter integrity in both the splenium and body of the corpus callosum, while only splenium integrity was associated with language and psychomotor function. Conclusion: Results suggest that, for typically developing adolescents, white matter coherence positively relates to visuospatial, psychomotor, and language skills. These findings may have implications for the cognitive functioning of clinical populations in which typical white matter development is altered.