Birth of an Abstraction: A Dynamical Systems Account of the Discovery of an Elsewhere Principle in a Category Learning Task

Human participants and recurrent (“connectionist”) neural networks were both trained on a categorization system abstractly similar to natural language systems involving irregular (“strong”) classes and a default class. Both the humans and the networks exhibited staged learning and a generalization pattern reminiscent of the Elsewhere Condition (Kiparsky, 1973). Previous connectionist accounts of related phenomena have often been vague about the nature of the networks’ encoding systems. We analyzed our network using dynamical systems theory, revealing topological and geometric properties that can be directly compared with the mechanisms of non‐connectionist, rule‐based accounts. The results reveal that the networks “contain” structures related to mechanisms posited by rule‐based models, partly vindicating the insights of these models. On the other hand, they support the one mechanism (OM), as opposed to the more than one mechanism (MOM), view of symbolic abstraction by showing how the appearance of MOM behavior can arise emergently from one underlying set of principles. The key new contribution of this study is to show that dynamical systems theory can allow us to explicitly characterize the relationship between the two perspectives in implemented models.     

A constitutive model for quasicrystal plasticity

High-pressure X-ray diffraction studies on gadolinium sesquioxide (Gd₂O₃) have been carried out up to a pressure of ～25 GPa in a diamond-anvil cell at room temperature. Gadolinium oxide, which has a cubic or bixbyite structure under ambient conditions, undergoes an irreversible structural phase at around 12 GPa. The high-pressure phase has been identified as a hexagonal La₂O₃-type structure. The bulk modulus and its pressure derivative of this phase have been calculated.     

Electron irradiation damage in SnO

In a study of radiation effects in SnO we have found that electron-beam damage is observable from changes in a high-resolution electron microscopy image or electron diffraction pattern. The early stage of the damage is not accompanied by a change in composition or a loss of crystallinity. The dose required for this damage (about 600 C cm^?2) is approximately independent of electron energy (between 100 and 400 keV) and specimen temperature (between 100 and 300 K). The damage is believed to start with displacement of oxygen atoms from their lattice position through a radiolytic mechanism with an efficiency of approximately 10^?4.     

Linear-parabolic shift of initially sharp interface in AB diffusion couple above the ordering temperature

It is shown that initially sharp interface in AB diffusion couple, above the ordering temperature, can shift with anomalous kinetics, i.e. deviations from the parabolic growth kinetics are possible. The initial slopes of the shift versus time functions can be even unity for large diffusion asymmetry (the ratio of diffusion coefficients of the parent materials in orders of magnitude) and gradually decrease to 0.5 at larger distances (longer times). This is in accordance with earlier results obtained in phase separating systems. It is shown that from the results of simulations the crossover thickness, X*, between the linear and parabolic regimes can also be calculated, and the applicability of the linear–parabolic law is confirmed. Furthermore, it is illustrated that the crossover thickness depends exponentially on the diffusion asymmetry parameter, with the exponent close to the value obtained from analytical estimations.     

Divine Action,Resurrection, and the Transformation of the Universe

Abstract

The article examines the notion of self-organization and explores the reality of biological processes from an epistemological point of view. First, I briefly analyze what is currently regarded as one of the most important discoveries not only in physics, but also in biology—namely, complex systems and deterministic chaos; secondly, I offer some reflections on the new frontiers of contemporary biology— namely, functional genomics and systems biology. The central part of the article focuses on the epistemological transition from genetic determinism to the new conception of “meaning” as emergence.     

视觉词汇加工的动态神经网络及其形成

揭示大脑加工的神经网络机制成为认知神经科学研究的最新取向.本研究以视觉词汇加工脑区(VWFA)的神经功能作为切入点,探讨视觉词汇加工神经网络的动态机制及其形成.研究一考察VWFA在刺激驱动和任务调节下的动态激活,及其与语音、语义脑区所组成神经网络的动态机制.研究二通过跨文化对比以及儿童阅读发展研究,阐明语言经验对视觉词汇加工网络的塑造作用.研究三对比功能网络、静息网络以及白质纤维束联结,探讨视觉词汇加工网络的动态联结及其形成.研究结果有助于建构视觉词汇加工的神经生理模型,为基于脑科学的阅读教学和阅读障碍矫治奠定理论基础,为认知神经科学研究提供了新的思路.     

伤害回避的脑机制及其生物基础

伤害回避是指个体对厌恶刺激信号做出强烈的反应,并学会被动地回避惩罚的一种倾向,这一倾向使得个体反复思考未来的结局,并谨慎小心地对待不确定情景中的事件,进而更有可能诱发情感障碍。伤害回避涉及的神经网络包括三个子网络,即额顶叶-前扣带皮层的连接、皮层-杏仁核的连接和白质通道的结构性连接,这三个子网络分别与羞怯感-易疲劳性、预期担心以及不确定环境中的害怕情绪有关。而其生物基础则包括单一基因多态性和基因多态间的交互作用。今后的研究应该集中在深化伤害回避神经网络与生物基础间的联合机制、研究三种及以上基因多态间的交互作用、考察其他因素对基因效应的调节作用、注重伤害回避四种亚型相关神经网络之间的连接、探讨5-HT4等其他几种5-羟色胺受体多态性与伤害回避的关系以及分析伤害回避内部机制在抗抑郁治疗中的作用等方面。     

PTSD and Epigenetic Research: Decentering the Physical Body

To prevent youth violence, the GREAT Families program was implemented with a selective sample of 1,196 families of sixth-grade children from low-income schools in 4 cities making the transition to adolescence. To assess intervention effects, we used pre- and posttest data to estimate a structural model to test the hypothesis that random assignment to the intervention would predict changes in parenting practices, which in turn would predict changes in exposure to violence (i.e., a mediational model). We found that participation in GREAT was significantly related to changes in parenting practices and these changes significantly predicted changes in violence exposure. Furthermore, adolescents who reported greater increases in exposure to violence also tended to experience greater decreases in parental monitoring, discipline, and involvement. Implications for future research and prevention efforts are discussed.     

Speaking up in ad hoc multiteam systems: Individual-level effects of psychological safety,status, and leadership within and across teams

Speaking up in high-risk organizations plays a pivotal role in the mitigation of errors and can make the difference between life and death. To date, speaking up has been studied mostly within teams. However, many high-risk organizations rely on the effective collaboration across teams in ad hoc multiteam systems (MTS). This study widens the scope of research from teams to MTS and empirically compares the mechanisms involved in speaking up within versus across teams in ad hoc MTS-aircrews. In a sample of 1490 aircrew members of a European airline, we found that crewmembers’ individual level perceptions of psychological safety mediated both the relationship between status and speaking up and between perceived leader inclusiveness and speaking up within teams. Across teams, however, psychological safety and leader inclusiveness—as perceived by pursers in their role as boundary spanners—showed no effect. Instead, it was pursers’ within-team perceptions of psychological safety that mediated between status and speaking up across teams. Teams in ad hoc MTS may thus serve as safe harbours supporting their members also in interactions across team boundaries. Implications of findings for research on MTS and practical recommendations to improve speaking up within and across teams in ad hoc MTS are discussed.     

Psychotherapy without the self–a Buddhist perspective,by Mark Epstein

This article seeks to explore how John Rolland's Family Systems Illness Model can be utilized by counselling psychologists working with individuals or families experiencing medical problems. Based on systemic theory the model provides a psychosocial typology of illness and examines how the demands of an illness over time can provide a number of hurdles to be overcome by the client and his/her family. Specific examples and techniques are described to illustrate how the application of the model can be used to guide the interventions employed in a counselling session. the model applies a biopsychosocial approach to health care, and the applicability of this within a British NHS healthcare setting is discussed with the conclusion that such an approach may be in its infancy in this country. Limitations and ideas for expansion of the model from chronic physical illness into spheres of mental health are discussed.