Recovery of fear memories in rats: Role of gamma-amino butyric acid (GABA) in infantile amnesia.

Infantile amnesia is a ubiquitous phenomenon, but its neural bases remain largely unknown. The authors identify a role for GABAergic transmission in suppressing retrieval of memories acquired in infancy. Eighteen-day-old rats received pairings of white noise and shock; considerable forgetting of this experience (assessed by freezing) occurred after 10 days. The memory was recovered by pretest administration of the GABAA inverse agonist FG7142 10 days, but not 2 months, after training. This effect of FG7142 generalized when a passive avoidance procedure was used. Also, FG7142 decreased fear of a latently inhibited conditioned stimulus, showing that the observed memory recovery effect was not due to a state-dependent process. It appears that GABA may be involved in infantile amnesia regardless of the emotional content of the memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Choosing the best method for local validity estimation: Relative accuracy of meta-analysis versus a local study versus Bayes-analysis.

This study assessed the relative accuracy of 3 techniques--local validity studies, meta-analysis, and Bayesian analysis--for estimating test validity, incremental validity, and adverse impact in the local selection context. Bayes-analysis involves combining a local study with nonlocal (meta-analytic) validity data. Using tests of cognitive ability and personality (conscientiousness) as predictors, an empirically driven selection scenario illustrates conditions in which each of the 3 estimation techniques performs best. General recommendations are offered for how to estimate local parameters, based on true population variability and the number of studies in the meta-analytic prior. Benefits of empirical Bayesian analysis for personnel selection are demonstrated, and equations are derived to help guide the choice of a local validity technique (i.e., meta-analysis vs. local study vs. Bayes-analysis). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Establishing an IT Architecture Strategy

An IT architecture strategy is based on the identification and definition of three levels of IS needs and solutions: strategy, architecture, and infrastructure. Mapping business technology needs into this hierarchy helps organizations ensure that potential technology solutions are driven by actual business requirements, not the reverse.     

Responding to the Needs of Children, Families, and Schools: The 2002 Multisite Conference on the Future of School Psychology.

The preparations for and the implementation of the 2002 Multisite Conference on the Future of School Psychology are described. The conference goals were to (a) achieve consensus on current and future demands for school psychologists and our profession's ability to meet those demands; (b) conceptualize the practice of school psychology in the face of diminishing numbers and increasing demand for services; and (c) develop an agenda to use the resources we have to maximize the benefits to the children and schools that we serve. A problem-solving model served as the conceptual foundation of the conference. School psychologists at the host site in Indianapolis and 30 remote sites collaborated to identify threats, opportunities, strategies, and action plans to respond better to the needs of children, families and schools. The conference not only generated excitement and hope for our future, but also provided a framework to propel the current and future practice of school psychology. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The ontogeny of fear-potentiated startle: Effects of earlier-acquired fear memories.

Research has shown that learned fear emerges in a response-specific sequence. For example, freezing is observed at a younger age than is potentiated startle (P. Hunt & B. A. Campbell, 1997). The present study shows that the age at which a specific learned fear response emerges is influenced by the animal's early experiences. Specifically, fear potentiation of startle emerges earlier in development if the rat is given prior fear conditioning to a different stimulus. Some constraints of this "facilitation" effect are determined in follow-up experiments. This facilitation effect may provide a novel way of testing the development of the neural circuits underlying learned fear. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

多媒体设备的融合趋势和挑战

消费者正在见证一场在各种媒体设备之间制作和共享多媒体内容能力的急剧转变.人们可以从数码相机上取出一段视频片断,将其存到一块适合他们个人数字助理(PDA)的存储卡中,以便乘坐火车时观看.     

The use of propane/isopentane mixtures for rapid freezing of biological specimens

The use of propane/isopentane mixtures as cooling media is proposed since they remain fluid at liquid nitrogen temperature. The attainable cooling rates are virtually identical to those obtained in liquid propane.     

Excuse theory: A test of the self-protective role of attributions.

Tested the hypothesis that individuals use consensus-raising, distinctiveness-raising, and consistency-lowering attributional explanations as strategies to excuse their poor performance on an ego-involving task. It was also predicted that such excuse-making tactics occurring after failure feedback, in comparison with those occurring after success feedback, lead to (1) decreased negative emotions when individuals anticipate that their excuse attempts will not be closely scrutinized by an informed or all-knowing audience, and (2) increased negative emotions when individuals anticipate that an evaluative audience has access to their private cognitions and feelings about their poor performance. 96 male undergraduate students were given high or low scores on a purported intelligence test and were administered a mood questionnaire and either items from Rotter's Internal–External Locus of Control Scale (control condition) or an excuse questionnaire (excuse condition). Results support the use of distinctiveness-raising and consistency-lowering, but not consensus-raising, attributional explanations. In addition, the predicted effects of excuse making on emotional state were generally obtained; that is, without the scrutiny of the all-knowing audience, the excuse making lessened negative affect after failure, whereas under the scrutiny of an all-knowing audience, excuse making served to increase negative affect. Results are discussed in terms of the circumstances under which excuse behaviors are construed as self-protective or self-defeating. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Tale of Two Classifier Systems

This paper describes two classifier systems that learn. These are rule-based systems that use genetic algorithms, which are based on an analogy with natural selection and genetics, as their principal learning mechanism, and an economic model as their principal mechanism for apportioning credit. CFS-C is a domain-independent learning system that has been widely tested on serial computers. CFS is a parallel implementation of CFS-C that makes full use of the inherent parallelism of classifier systems and genetic algorithms, and that allows the exploration of large-scale tasks that were formerly impractical. As with other approaches to learning, classifier systems in their current form work well for moderately-sized tasks but break down for larger tasks. In order to shed light on this issue, we present several empirical studies of known issues in classifier systems, including the effects of population size, the actual contribution of genetic algorithms, the use of rule chaining in solving higher-order tasks, and issues of task representation and dynamic population convergence. We conclude with a discussion of some major unresolved issues in learning classifier systems and some possible approaches to making them more effective on complex tasks.