Testing the Adult Development Tower of Babel Hypothesis: Homogeneous by Perry Position Collaborative Learning Groups and Graduate Student Satisfaction

The purpose of this quasi-experimental study was to investigate what appears to be a grounding assumption in some adult developmental and educational research: persons of differing epistemologies who are grouped together will understand one another less well than persons who are grouped homogeneously. A robust effect is discussed within the context of adult development theory, research on collaborative learning groups, and Bruffee's social constructionist challenge (K. A. Bruffee, 1993) to Perry and to cognitive development theory. Collateral research questions relating to covariates of developmental position (according to the Perry scheme) are entertained; confirmatory qualitative data are presented.     

肿瘤干细胞起源与鉴定方法研究现状

CSC理论使人们对恶性肿瘤有了一个全新的认识,为临床治疗提供了一个全新视角。该理论改变目前以全部癌细胞为目标的药物治疗策略,将使治愈肿瘤成为可能。分离和鉴定CSC是CSC靶向治疗的第一步。本文就CSC的起源和鉴定方法做一简要综述。     

Low environmental calcium blocks long-term memory formation in a freshwater pulmonate snail

The freshwater snail Lymnaea stagnalis (L.) is considered a calciphile and exhibits reduced growth and survival in environments containing less than 20 mg/l environmental calcium. Although it has no apparent effect on survival at 20 mg/l, reducing environmental calcium increases metabolic demand, and as such we consider that this level of calcium acts as a stressor on the snail. We exposed snails to acute periods of low environmental calcium and tested their ability to form intermediate-term memory (ITM) and long-term memory (LTM) following one trial operant conditioning (1TT) to reduce aerial respiratory activity in hypoxic conditions. We also assessed whether there were changes in the electrophysiological properties of a single neuron, right pedal dorsal 1 (RPeD1), which has been demonstrated to be necessary for LTM formation. Following training in high (80 mg/l) environmental calcium, L. stagnalis formed ITM and LTM lasting 24 h and demonstrated a significant reduction in all activity measured from RPeD1; however when snails were exposed to low (20 mg/l) environmental calcium they were able to form ITM but not LTM. Although no behavioral LTM was formed, a partial reduction in RPeD1 activtiy measured 24 h after training was observed, indicating a residual effect of training. The strong effect that environmental calcium concentration had on physiology and behavior in response to training to reduce aerial respiration in L. stagnalis suggests that it is an element of gastropod husbandry that needs to be carefully considered when studying other traits. This study also indicates that L. stagnalis found naturally in low calcium environments may be less able to adapt to novel stressors than populations found in harder waters.     

Interference with reelin signaling in the lateral entorhinal cortex impairs spatial memory

Entorhinal neurons receive extensive intracortical projections, and form the primary input to the hippocampus via the perforant pathway. The glutamatergic cells of origin for the perforant pathway are distinguished by their expression of reelin, a glycoprotein involved in learning and synaptic plasticity. The functional significance of reelin signaling within the entorhinal cortex, however, remains unexplored. To determine whether interrupting entorhinal reelin signaling might have consequences for learning and memory, we administered recombinant receptor-associated protein (RAP) into the lateral entorhinal cortex (LEC) of young Long-Evans rats. RAP prevents reelin from binding to its receptors, and we verified the knockdown of reelin signaling by quantifying the phosphorylation state of reelin’s intracellular signaling target, disabled-1 (DAB1). Effective knockdown of reelin signaling was associated with impaired performance in the hippocampus-dependent version of the water maze. Moreover, inhibition of reelin signaling induced a localized loss of synaptic marker expression in the LEC. These observations support a role for entorhinal reelin signaling in spatial learning, and suggest that an intact reelin signaling pathway is essential for synaptic integrity in the adult entorhinal cortex.     

学业优秀者和学业不良者的倒摄抑制比较 ——从结构化和非结构化角度

以汉字为实验材料,以学业优秀者和学业不良者为被试,探讨学习材料的结构化和非结构化性质对倒摄抑制产生的影响,以及两类学生学习两类材料时的倒摄抑制差异。并通过指导语,逐步揭示结构化材料中的规则,迫使被试采用有效的学习策略,来观察倒摄抑制的变化情况。结果表明:一、与非结构化材料相比,学习结构化材料表现出更好的记忆绩效,但未发现两者对倒摄抑制的不同影响;二、和学优者相比,学业不良者的记忆绩效较差,倒摄抑制值也较大;三、对材料规则的提示会促进学业不良学生的记忆绩效,降低倒摄抑制,但对学习优秀者的影响不大;四、一些汉字识别特征影响倒摄抑制,如当干扰项和目标项构形相同时,会降低倒摄抑制。     

Learning language from the input: why innate constraints can't explain noun compounding

Do the production and interpretation of patterns of plural forms in noun-noun compounds reveal the workings of innate constraints that govern morphological processing? The results of previous studies on compounding have been taken to support a number of important theoretical claims: first, that there are fundamental differences in the way that children and adults learn and process regular and irregular plurals, second, that these differences reflect formal constraints that govern the way the way regular and irregular plurals are processed in language, and third, that these constraints are unlikely to be the product of learning. In a series of seven experiments, we critically assess the evidence that is cited in support of these arguments. The results of our experiments provide little support for the idea that substantively different factors govern the patterns of acquisition, production and interpretation patterns of regular and irregular plural forms in compounds. Once frequency differences between regular and irregular plurals are accounted for, we find no evidence of any qualitative difference in the patterns of interpretation and production of regular and irregular plural nouns in compounds, in either adults or children. Accordingly, we suggest that the pattern of acquisition of both regular and irregular plurals in compounds is consistent with a simple account, in which children learn the conventions that govern plural compounding using evidence that is readily available in the distribution patterns of adult speech.     

汉语句子理解中句法启动机制的眼动和ERP研究

语言产生的句法启动效应在近20年得到较深入研究。那么, 语言理解和语言产生中, 句法启动效应具有相同的加工机制吗？近些年, 研究者考察了印欧语系语言理解中的启动效应, 但还存在较多争论。这究竟是句法效应, 还是策略或者语义效应, 是词汇驱动还是词汇独立的？而且, 这是人类语言理解的语系特性还是普遍特性？单独采用行为技术、眼动技术或者ERP技术很难为这些争论提供坚实的实验证据和较深入的理论解释。鉴于此, 本项目拟采用眼动和ERP结合的技术, 从心理学、语言学和认知神经科学等多学科交叉的视角考查汉语句子理解的句法启动效应。通过分析眼动和ERP实验提供的一致性和差异性证据, 本项目力图阐明和揭示汉语句子理解中句法启动效应的认知特点和机制, 检验内隐学习理论和论元结构理论在解释句法启动效应时的适用性。     

情绪语音调节面孔表情的识别：ERP证据

采用事件相关电位（ERP）技术考察了情绪语音影响面孔表情识别的时间进程。通过设置效价一致或不一致的“语音-面孔”对,要求被试判断情绪语音和面孔表情的效价是否一致。行为结果显示,被试对效价一致的“语音-面孔”对的反应更快。ERP结果显示,在70-130ms和220-450ms,不一致条件下的面孔表情比一致条件诱发了更负的波形;在450-750ms,不一致条件下的面孔表情比一致条件诱发更正的后正成分。说明情绪语音对面孔表情识别的多个阶段产生了跨通道影响。     

Reflections on the deBroglie–Bohm Quantum Potential

The deBroglie–Bohm quantum potential is the potential energy function of the wave field. The quantum potential facilitates the transference of energy from wave field to particle and back again which accounts for energy conservation in isolated quantum systems. Factors affecting energy exchanges and the form of the quantum potential are discussed together with the related issues of the absence of a source term for the wave field and the lack of a classical back reaction.     

Changes in processing of masked stimuli across early- and late-night sleep: a study on behavior and brain potentials

Sleep has proven to support the memory consolidation in many tasks including learning of perceptual skills. Explicit, conscious types of memory have been demonstrated to benefit particularly from slow-wave sleep (SWS), implicit, non-conscious types particularly from rapid eye movement (REM) sleep. By comparing the effects of early-night sleep, rich in SWS, and late-night sleep, rich in REM sleep, we aimed to separate the contribution of these two sleep stages in a metacontrast masking paradigm in which explicit and implicit aspects in perceptual learning could be assessed separately by stimulus identification and priming, respectively. We assumed that early sleep intervening between two sessions of task performance would specifically support stimulus identification, while late sleep would specifically support priming. Apart from overt behavior, event-related EEG potentials (ERPs) were measured to record the cortical mechanisms associated with behavioral changes across sleep. In contrast to our hypothesis, late-night sleep appeared to be more important for changes of behavior, both for stimulus identification, which tended to improve across late-night sleep, and for priming, with the increase of errors induced by masked stimuli correlating with the duration of REM sleep. ERP components proved sensitive to presence of target shapes in the masked stimuli and to their priming effects. Of these components, the N2 component, indicating processing of conflict, became larger across early-night sleep and was related to the duration of S4 sleep, the deepest substage of SWS containing particularly high portions of EEG slow waves. These findings suggest that sleep promotes perceptual learning primarily by its REM sleep portion, but indirectly also by way of improved action monitoring supported by deep slow-wave sleep.