Assessment of working memory components at 6years of age as predictors of reading achievements a year later

The ability of working memory skills (measured by tasks assessing all four working memory components), IQ, language, phonological awareness, literacy, rapid naming, and speed of processing at 6 years of age, before reading was taught, to predict reading abilities (decoding, reading comprehension, and reading time) a year later was examined in 97 children. Among all working memory components, phonological complex memory contributed most to predicting all three reading abilities. A capacity measure of phonological complex memory, based on passing a minimum threshold in those tasks, contributed to the explained variance of decoding and reading comprehension. Findings suggest that a minimal ability of phonological complex memory is necessary for children to attain a normal reading level. Adding assessment of phonological complex memory, before formal teaching of reading begins, to more common measures might better estimate children’s likelihood of future academic success.     

环境雌激素双酚A对成年小鼠学习记忆和突触结构的影响*

双酚A (bisphenol, BPA)是一种广泛存在的环境内分泌干扰物,它可与雌激素受体结合干扰内源性雌激素对中枢神经系统的调控作用。本研究通过将10周龄小鼠灌胃染毒BPA (0.4、4、40 mg/kg/day)3个月,研究长期BPA暴露对成年小鼠记忆行为和突触可塑性的影响。开场行为测试结果表明, BPA (0.4、4、40 mg/kg/day)增加雄性的站立次数和理毛频率, BPA (4 mg/kg/day)却显著减少雌鼠的站立次数。水迷宫和被动回避行为模型检测显示, BPA主要损伤雄鼠的空间学习记忆和被动回避记忆。通过制备海马CA1区超薄切片后,电镜观测发现, BPA (0.4、40 mg/kg/day)暴露降低雄鼠海马CA1区突触数密度,缩短雄鼠突触前活性带长度,减小雄鼠突触后致密体(PSD)厚度,增加雄鼠突触间隙宽度。进一步用Western blot方法检测突触前、后的标志性蛋白Synapsin I和PSD95以及兴奋性氨基酸NMDA受体NR1亚基和AMPA受体GluR1亚基蛋白的表达,发现BPA暴露致雄鼠Synapsin I、PSD95、NR1蛋白表达水平下调。而BPA对雌鼠的记忆行为、突触形态、突触蛋白和受体蛋白均没有明显作用。以上结果提示长期B PA暴露性别特异性地影响成年小鼠的活动性和探究行为,损伤雄鼠的学习记忆,这些作用可能通过下调突触蛋白和NMDA受体的表达而负性影响突触结构可塑性,最终影响雄鼠的学习记忆功能。     

Language aptitude for pronunciation in advanced second language (L2) Learners: Behavioural predictors and neural substrates

Individual differences in second language (L2) aptitude have been assumed to depend upon a variety of cognitive and personality factors. Especially, the cognitive factor phonological working memory has been conceptualised as language learning device. However, strong associations between phonological working memory and L2 aptitude have been previously found in early-stage learners only, not in advanced learners. The current study aimed at investigating the behavioural and neurobiological predictors of advanced L2 learning. Our behavioural results showed that phonetic coding ability and empathy, but not phonological working memory, predict L2 pronunciation aptitude in advanced learners. Second, functional neuroimaging revealed this behavioural trait to be correlated with hemodynamic responses of the cerebral network of speech motor control and auditory-perceptual areas. We suggest that the acquisition of L2 pronunciation aptitude is a dynamic process, requiring a variety of neural resources at different processing stages over time.     

Gender differences in autobiographical memory: Developmental and methodological considerations

Gender differences have surfaced in inconsistent ways in autobiographical memory studies. When apparent, researchers find gender differences such that women report more vivid memory experiences than men and women include more details about emotions, about other people, and about the meaningfulness of their memories. Specifically, females include more emotion, more elaboration, and a greater sense of connectedness to others in their narratives, and we consider the possible connection between these tendencies and women’s advantage on a number of autobiographical and episodic memory tasks. However, not all studies of autobiographical memory find gender differences. We propose that gender differences in autobiographical memory development and interpersonal socialization contribute to the differences found, and that gender differences can be attributed, at least in part, to the influence of conversations with parents when autobiographical memory skills are developing. An examination of studies in which gender differences are not found suggests that specific instructions, context, gender salience, and the type of autobiographical memory measure used can mitigate gender differences. We conclude by outlining future directions for research, including longitudinal studies and experiments designed to systematically examine gender in autobiographical memory for its own sake.     

Selection of Decision Strategies After Conscious and Unconscious Thought

It is commonly assumed that the use of simple, non‐compensatory strategies is especially pronounced in memory‐based decisions, where information costs are high. At the same time, there is evidence that in memory‐based decisions, a compensatory processing of attributes is facilitated when the processing occurs unconsciously rather than consciously. We applied a strategy classification approach—developed in research on non‐compensatory heuristics—to test two key tenets of unconscious thought theory: the capacity principle and the weighting principle. Participants memorized attribute information about cars and were subsequently either directed to or diverted from thinking consciously about their preferences between the cars (conscious versus unconscious thought). Then, participants indicated in pair‐wise choices which car they would prefer and were classified (based on their choices) as using either one of two compensatory strategies (equal weight or weighted additive) or a non‐compensatory strategy (lexicographic heuristic). In line with the capacity principle, the number of participants best described by a compensatory strategy (the equal‐weight strategy) tended to be higher after unconscious thought than after conscious thought, whereas the number of participants best described by the lexicographic heuristic tended to be lower. Inconsistent with the weighting principle, participants in the unconscious thought condition were better described by the equal‐weight strategy than by the weighted‐additive strategy. In Experiment 2, in which participants were not instructed to form an impression while learning the attribute information, the use of the equal‐weight strategy was not more prevalent after unconscious thought. Copyright © 2013 John Wiley & Sons, Ltd.     

Memories defining the self in Alzheimer’s disease

ABSTRACT

There is a debate over the extent to which personal identity or the self is preserved in patients with Alzheimer’s disease (AD). Autobiographical memory deficits at early stages of AD could contribute to altering patients’ self. However, the nature of the relationship between autobiographical memory deficits and the self in AD has not been much investigated experimentally. In the present study, we aimed to investigate the integrative meaning of self-defining memories (SDMs) in early stages of AD and to analyse its relationship with the self-concept. The results showed that, when compared to the control group, AD patients less frequently extracted meaning from their SDMs and the meaning was less frequently tied to the self. Patients exhibited some altered aspects of the self-concept (i.e., complexity and strength), though some other components still persisted (i.e., valence and certainty). Correlation analyses showed that the impaired integrative meaning in the AD group was correlated with some changes in self-concept. We suggest that integrative meaning may act as a bridge between autobiographical memories and the self-concept, with reduced integration abilities appearing as a potential mechanism for the deterioration of the self-concept in AD.     

The natural history of information processors

By spanning the traditional scientific theories in the search for an epistemological home for information it is found that Physics (together with some inputs from Automata Theory) provides the criteria to identify the universals that characterize information processors. It is well known, however, that Physics and Mathematics alone are insufficient to answer some fundamental questions that arise in further speculations on the subject of information. It seems that Biology, in the realm of Evolution Theory and in terms of Natural Selection, is at present the only place able to offer the objective context required to properly characterize information as an object of scientific inquiry.

In this communication we intend to show, by establishing a working equivalence between the epistemological questions that should characterize a theory of information and those questions that characterize the science of Biology, how a science of information can be more objectively characterized. It is only by referring to selective pressures that we can solve the otherwise unanswerable philosophical question of whether it is possible to know if two players of a game are, in fact, playing the same game (the semantic question). It is also shown that it is possible, by using conventional criteria, to establish a phylogenesis of information processors from where we conclude that every information processor now existing in the universe (even computers and robots) has an ancestor that has once been a living being.

It is here suggested, however, that Biology is only a provisory epistemological ground for laying the foundations of an information science. A more inclusive theory should be founded on a generalization of the Theory of Evolution where mutation and natural selection should be described, not in terms of the characteristic media and mechanisms of biological systems, but of the identified universals of information processors.     

Intra-Individual Variability Among Children with ADHD on a Working Memory Task: An Ex-Gaussian Approach

Intra-individual variability on a computer-based working memory task was examined among 25 children/adolescents with ADHD and 24 typically developing peers. Participants completed the Visual Serial Addition Task (VSAT) and reaction time data were fit to an ex-Gaussian distribution. ADHD participants demonstrated significantly more variable performance than controls, and effects of working memory load were observed. Event rate, however, had no influence on group differences in performance. Follow-up correlations revealed associations between VSAT performance and ADHD symptomatology. This study supports intra-individual variability as a hallmark feature of ADHD beyond the domain of response inhibition and reinforces the need to consider variability in ADHD more broadly.     

The Origin of Error

The present two experiments were designed to investigate the effects of two competing retrieval strategies—category and position cueing.

One hundred college students participated in Experiment I in which Presentation Rate, List Type, and Stimulus Position were manipulated within an FR paradigm. Sixty students participated in Experiment II in which Formal Response Similarity and Stimulus Position were manipulated within a PA paradigm.

Findings were the following: (a) that greater clustering and FR is obtained at slower presentation rates; (b) that greater than chance clustering occurs with a category list structure; and (c) that HS response learning is more difficult than LS response learning. No support was found for position cueing.

Results were discussed within FR cueing, von Restorff, and intentional versus incidental learning paradigms as possible explanations for the nonsignificant position cueing results in the present experiments. A competing strategy hypothesis of category and position cues was preferred with category recall and clustering as the dominant mode of retrieval.     

Demand Transitions and Sustained Attention

A recent report by the National Research Council (Huey & Wickens, 1993) has identified transitions in task demand as an important dimension for study in vigilance research. This experiment tested the possibility that the effects of such transitions follow a relatively simple psychophysical rule—they are characterized by contrast effects. Transitions in task demand were achieved by shifting subjects from single-task to dual-task monitoring and vice versa. These transitions produced changes in subjects' sensing and decision-making functions that were far more intricate than simple contrast effects. The demand transition issue offers a complex research challenge on both basic and applied levels and warrants further investigation.