Associative learning performance is impaired in zebrafish (Danio rerio) by the NMDA-R antagonist MK-801

The zebrafish is gaining popularity in behavioral neuroscience perhaps because of a promise of efficient large scale mutagenesis and drug screens that could identify a substantial number of yet undiscovered molecular players involved in complex traits. Learning and memory are complex functions of the brain and the analysis of their mechanisms may benefit from such large scale zebrafish screens. One bottleneck in this research is the paucity of appropriate behavioral screening paradigms, which may be due to the relatively uncharacterized nature of the behavior of this species. Here we show that zebrafish exhibit good learning performance in a task adapted from the mammalian literature, a plus maze in which zebrafish are required to associate a neutral visual stimulus with the presence of conspecifics, the rewarding unconditioned stimulus. Furthermore, we show that MK-801, a non-competitive NMDA-R antagonist, impairs memory performance in this maze when administered right after training or just before recall but not when given before training at a dose that does not impair motor function, perception or motivation. These results suggest that the plus maze associative learning paradigm has face and construct validity and that zebrafish may become an appropriate and translationally relevant study species for the analysis of the mechanisms of vertebrate, including mammalian, learning and memory.     

Stimulus/response learning in masked congruency priming of faces: Evidence for covert mental classifications?

Reaction times for categorization of a probe face according to its sex or fame were contrasted as a function of whether the category of a preceding, sandwich-masked prime face was congruent or incongruent. Prime awareness was measured by the ability to later categorize the primes, and this was close to chance and typically uncorrelated with priming. When prime faces were never presented as visible probes within a test, priming was not reliable; when prime faces were also seen as probes, priming was only reliable if visible and masked presentation of faces were interleaved (not simply if primes had been visible in a previous session). In the latter case, priming was independent of experimentally induced face–response or face–category contingencies, ruling out any simple form of stimulus–response learning. We conclude that the reliable masked congruency priming reflects bindings between stimuli and multiple, abstract classifications that can be generated both overtly and covertly.     

Digit Span and Articulatory Suppression: A Cross-linguistic Comparison

Information Reduction, a performance-enhancing cognitive strategy which develops with practice, is thought to be consciously and abruptly adopted and then applied consistently. Previous investigations used an Alphabet Verification Task where one observation was that not everyone adopts the strategy, but reasons for this are unclear. We demonstrated Information Reduction in three other tasks, confirming that it is not task-specific. Post-testing questionnaires probed verbally expressible knowledge, to gauge conscious awareness of any strategy. Overall, results indicate considerable variation in Information Reduction usage: Some individuals discovered and used the strategy and could verbally express this, others chose not to use it and some appeared to use it without awareness of doing so. Results also indicate that Information Reduction is not consistently applied, suggesting it is less robust than has been proposed. Our results may be better explained by a theory of practice learning which incorporates both data-driven automaticity and top-down controlled processes.     

Spreading the words: A spacing effect in vocabulary learning

The spacing effect refers to the frequently observed finding that distributing learning across time leads to better retention than massing it into one single study session. In the present study, we examined whether the spacing effect generalises to primary school vocabulary learning. To this aim, children from Grade 3 were taught the meaning of 15 new words using a massed procedure and 15 other new words using a spaced procedure. The 15 words in the massed condition were divided into three sets of five words, and each set was taught three times in one of three learning sessions. In the spaced condition, learning was distributed across the three sessions: All 15 words were practised once in each of the three learning sessions. At the retention tests after 1 week and after 5 weeks we observed that the meaning of spaced words was remembered better than the meaning of massed words.     

Learning climate scale: Construction,reliability and initial validity evidence

The current study developed an instrument for measuring learning climate in organizations. A review of the organizational learning and facilitation of workplace learning literature resulted in three theoretically relevant dimensions referring to facilitation, appreciation, and error avoidance. The 3-dimensional learning climate scale (LCS) was tested in a heterogeneous sample of Dutch wage earners (N = 1013). Confirmatory factor analysis and analysis of measurement invariance were conducted to establish the factorial structure of the measure. Also, convergent, divergent, and construct validity of the LCS were investigated. The findings showed that the newly developed instrument for learning climate has good psychometric properties: the three-factor structure was supported and the sub-scales were reliable. Furthermore, the LCS showed good convergent and divergent validity.     

Attention focusing instructions and coordination bias: Implications for learning a novel bimanual task

Four groups learnt a novel bimanual coordination movement pattern under instructions designed to manipulate focus of attention. It was predicted that instructions directing attention onto the effects of the action would facilitate learning. Three groups received demonstrations of the required 90° relative phase movement. Two of the demonstration groups also received instruction directing attention either towards the feedback (EXTERNAL), or the relationship between their arm movements and the feedback (RELATION). The third group received no attention directing instructions (DEMO). A final group was only provided with goal relevant feedback (NO DEMO). A scanning task enabled coordination bias to be assessed pre-practice. This was conducted to ensure task novelty and assign participants equally across groups based on strength of bias to in- and/or anti-phase. Acquisition rate was slower for the DEMO only group, especially compared to the EXTERNAL group. Additionally, participants biased to in-phase (as compared to anti-phase) during the scanning trial also showed high error early in practice. These differences remained in retention. Irrespective of feedback condition the DEMO group evidenced the most error in retention. However, all groups were affected by the removal of on-line feedback, although the attention-directing instructions provided during practice somewhat decreased the negative effects associated with feedback removal. Overall, the in-phase-biased participants were most affected by withdrawal of feedback. It was concluded that movement demonstrations alone do not facilitate learning of a novel coordination task, unless additional goal-directed instruction is provided. Additionally, individual differences in coordination bias pre-practice can be used to predict learning rate and quality.     

北京地区中学生学习策略水平的调查研究

本研究采用中学生学习策略量表测查了542名中学生的学习策略使用情况。结果表明：(1)中学生学习策略量表有着较高的信度和效度,分量表项目间有良好的一致性。(2)从初三到高三,学生的学习策略水平没有表现出随年级增长而提高的趋势,甚至在时问管理、焦虑、信息加工等分量表方面有下降的表现。(3)女生在态度,动机,学习辅助和自我测试分量表上的得分明显高于男生;男生在信息加工分量表上的得分明显高于女生。(4)优差生在学习辅助和自我测试两个分量表上的得分没有明显差异,在其余分量表上均有显著差异。     

初中生生活事件、心理韧性与学习倦怠的关系

目的:探讨初中生的学习倦怠、生活事件和心理韧性的关系。方法:从济宁市四所初级中学抽取465名初中生,以青少年生活事件量表、青少年心理韧性量表、中学生学习倦怠问卷为研究工具,对初中生进行测查。结果:初中生的学习倦怠水平随年级增长呈逐渐升高趋势;男生的学习倦怠水平显著高于女生;心理韧性作为中介变量,影响到生活事件与学习倦怠之间的关系,中介效应占总效应的比例为42.4%。结论:培养学生的心理韧性可以有助于降低他们的学习倦怠水平。     

Systemic and local administration of estradiol into the prefrontal cortex or hippocampus differentially alters working memory

The influence of estradiol on learning and memory is dependent on a number of factors. The effects of physiological levels of estradiol on the acquisition of a spatial working memory task mediated by the prefrontal cortex (PFC) and the hippocampus were examined in Experiment 1. Ovariectomized Long-Evans rats received daily injections of estradiol or vehicle were tested on the win-shift version of the radial arm maze. A high dose of estradiol benzoate (5 microg) enhanced acquisition of the task, whereas a low dose of estradiol (0.3 microg) increased the number of errors committed over 17 days of testing. Experiment 2 was conducted to examine site-specific influences of estradiol on spatial working memory in well-trained rats. Saline and estradiol cyclodextrin (0.1 and 0.9 microg) were infused into the prelimbic region of the PFC or dorsal hippocampus 40 min prior to testing on the win-shift task. Infusions of estradiol into both brain areas attenuated saline-infusion disruptions in working memory. Specifically, the higher dose of estradiol facilitated working memory when infused into the PFC, whereas the lower dose of estradiol facilitated performance when infused into the dorsal hippocampus. Moreover, working memory was significantly impaired 24 h after infusions of estradiol into the dorsal hippocampus but not the PFC. These data provide further evidence for the notion that estradiol can dose-dependently alter memory processes and suggest that facilitation or disruptions of working memory by estradiol are site- and time-specific.