Connectionist models of artificial grammar learning: what type of knowledge is acquired?

Two experiments are presented that test the predictions of two associative learning models of Artificial Grammar Learning. The two models are the simple recurrent network (SRN) and the competitive chunking (CC) model. The two experiments investigate acquisition of different types of knowledge in this task: knowledge of frequency and novelty of stimulus fragments (Experiment 1) and knowledge of letter positions, of small fragments, and of large fragments up to entire strings (Experiment 2). The results show that participants acquired all types of knowledge. Simulation studies demonstrate that the CC model explains the acquisition of all types of fragment knowledge but fails to account for the acquisition of positional knowledge. The SRN model, by contrast, accounts for the entire pattern of results found in the two experiments.

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The influence of information redundancy on probabilistic inferences

Information redundancy affects the accuracy of inference strategies. A simulation study illustrates that under high-information redundancy simple heuristics that rely on only the most important information are as accurate as strategies that integrate all available information, whereas under low redundancy integrating information becomes advantageous. Assuming that people exercise adaptive strategy selection, it is predicted that their inferences will more often be captured by simple heuristics that focus on part of the available information insituations ofhigh-information redundancy, especially when information search is costly. This prediction is confirmed in two experiments. The participants' task was to repeatedly infer which of two alternatives, described by several cues, had a higher criterion value. In the first experiment, simple heuristics predicted the inference process better under high-information redundancy than under low-information redundancy. In the second experiment, this result could be generalized to an inference situation in which participants had no prior opportunity to learn about the strategies' accuracies through outcome feedback. The results demonstrate that people are able to respond adaptively to different decision environments under various learning opportunities.     

The neural regions sustaining episodic encoding and recognition of objects

In this functional MRI experiment, encoding of objects was associated with activation in left ventrolateral prefrontal/insular and right dorsolateral prefrontal and fusiform regions as well as in the left putamen. By contrast, correct recognition of previously learned objects (R judgments) produced activation in left superior frontal, bilateral inferior frontal, and right cerebellar regions, whereas correct rejection of distractor objects (N judgments) was associated with activation in bilateral prefrontal and anterior cingulate cortices, in right parietal and cerebellar regions, in the left putamen, and in the right caudate nucleus. The R minus N comparison showed activation in the left lateral prefrontal cortex and in bilateral cingulate cortices and precunei, while the N minus R comparison did not reveal any positive signal change. These results support the view that similar regions of the frontal lobe are involved in episodic encoding and retrieval processes, and that the successful episodic retrieval of newly learned objects is mainly based on a frontoparietal network.     

An Examination of the Psychometric Properties and Factor Structure of the Feelings of Stigmatization Questionnaire

As the experience of stigma and its psychological dimensions require careful measurement, the purpose of this study was to examine the psychometric properties and factor structure of the Feelings of Stigmatization Questionnaire (FSQ). A total of 170 participants with psoriasis and 124 with atopic dermatitis (AD) completed the FSQ. AD participants self-rated AD severity, while psoriasis severity was determined by a clinician. Confirmatory (CFA) and exploratory factor analytic (EFA) techniques were used to examine the factor structure of the FSQ. The FSQ total score was not related to age, age at onset, illness duration or psoriasis severity but it was negatively associated with AD severity (r = −.25, p < .01). The original six-factor structure of the FSQ was not replicated in our sample. Using EFA, a fixed three-factor solution proved the most stable, with the dimensions of feeling flawed, anticipation of rejection and secrecy, and positive attitudes towards skin disease being identified.     

High impact running improves learning

Regular physical exercise improves cognitive functions and lowers the risk for age-related cognitive decline. Since little is known about the nature and the timing of the underlying mechanisms, we probed whether exercise also has immediate beneficial effects on cognition. Learning performance was assessed directly after high impact anaerobic sprints, low impact aerobic running, or a period of rest in 27 healthy subjects in a randomized cross-over design. Dependent variables comprised learning speed as well as immediate (1 week) and long-term (>8 months) overall success in acquiring a novel vocabulary. Peripheral levels of brain-derived neurotrophic factor (BDNF) and catecholamines (dopamine, epinephrine, norepinephrine) were assessed prior to and after the interventions as well as after learning. We found that vocabulary learning was 20 percent faster after intense physical exercise as compared to the other two conditions. This condition also elicited the strongest increases in BDNF and catecholamine levels. More sustained BDNF levels during learning after intense exercise were related to better short-term learning success, whereas absolute dopamine and epinephrine levels were related to better intermediate (dopamine) and long-term (epinephrine) retentions of the novel vocabulary. Thus, BDNF and two of the catecholamines seem to be mediators by which physical exercise improves learning.     

论心理学文化品性

长期以来,关于心理学性质的理解一直存有争论,人们总是以自己的哲学观、心理观和理智背景来认识和解说心理学性质.从文化哲学视角来分析和探讨,会揭示出心理学对象、心理学者研究立场、心理学概念、心理学知识基础、心理学思维方式等诸要素与一定的价值立场和文化传统之间有着内在关联,其背后是强大的文化支持系统,这从整体上凸显了心理学的文化品性.探讨心理学文化品性旨在发现和建构心理学新的话语实践,使之成为重新解读心理学立论依据.     

面孔和汉字双关图的反转效应

面孔认知的反转效应已经得到了很多研究的证实.本研究使用结构信息改变的面孔、汉字和双关图作为实验材料.被试在经过面孔或者汉字的启动任务之后,可以将双关图知觉为面孔或者汉字.结果显示:在对面孔的相对辨认情景中,被试对反转面孔的反应时间显著长于正立面孔,存在反转效应.在对汉字的相对辨认情景中,正立和反转汉字的反应时间没有显著差异.这一结果表明反转效应不仅和结构信息有关,面孔专家化系统自上而下的激活对面孔反转效应起到重要的作用.     

More efficient parameter estimates for factor analysis of ordinal variables by ridge generalized least squares

Data in psychology are often collected using Likert‐type scales, and it has been shown that factor analysis of Likert‐type data is better performed on the polychoric correlation matrix than on the product‐moment covariance matrix, especially when the distributions of the observed variables are skewed. In theory, factor analysis of the polychoric correlation matrix is best conducted using generalized least squares with an asymptotically correct weight matrix (AGLS). However, simulation studies showed that both least squares (LS) and diagonally weighted least squares (DWLS) perform better than AGLS, and thus LS or DWLS is routinely used in practice. In either LS or DWLS, the associations among the polychoric correlation coefficients are completely ignored. To mend such a gap between statistical theory and empirical work, this paper proposes new methods, called ridge GLS, for factor analysis of ordinal data. Monte Carlo results show that, for a wide range of sample sizes, ridge GLS methods yield uniformly more accurate parameter estimates than existing methods (LS, DWLS, AGLS). A real‐data example indicates that estimates by ridge GLS are 9–20% more efficient than those by existing methods. Rescaled and adjusted test statistics as well as sandwich‐type standard errors following the ridge GLS methods also perform reasonably well.