Learning related modulation of functional retrieval networks in man

The medial temporal lobe has been implicated in studies of episodic memory tasks involving spatio-temporal context and object-location conjunctions. We have previously demonstrated that an increased level of practice in a free-recall task parallels a decrease in the functional activity of several brain regions, including the medial temporal lobe, the prefrontal, the anterior cingulate, the anterior insular, and the posterior parietal cortices, that in concert demonstrate a move from elaborate controlled processing towards a higher degree of automaticity. Here we report data from two experiments that extend these initial observations. We used a similar experimental approach but probed for effects of retrieval paradigms and stimulus material. In the first experiment we investigated practice related changes during recognition of object-location conjunctions and in the second during free-recall of pseudo-words. Learning in a neural network is a dynamic consequence of information processing and network plasticity. The present and previous PET results indicate that practice can induce a learning related functional restructuring of information processing. Different adaptive processes likely subserve the functional re-organisation observed. These may in part be related to different demands for attentional and working memory processing. It appears that the role(s) of the prefrontal cortex and the medial temporal lobe in memory retrieval are complex, perhaps reflecting several different interacting processes or cognitive components. We suggest that an integrative interactive perspective on the role of the prefrontal and medial temporal lobe is necessary for an understanding of the processing significance of these regions in learning and memory. It appears necessary to develop elaborated and explicit computational models for prefrontal and medial temporal functions in order to derive detailed empirical predictions, and in combination with an efficient use and development of functional neuroimaging approaches, to further the understanding of the processing significance of these regions in memory.     

Does dyslexia develop from learning the alphabet in the wrong hemisphere? A cognitive neuroscience analysis

A new perspective is described which views developmental dyslexia as the outcome of learning to write the alphabet in the nondominant (right) hemisphere. The letter-level and whole-word subtypes of dyslexia are seen as differing responses adopted to cope with this predicament. Striking similarities between dyslexics and callosotomy patients in the allocation of covert attention to lateralized stimuli provide direction for integrating a diversity of dyslexic research within this framework. This synthesis, together with information from pure alexia, brain activation, and reading research, lends insight into the neural circuitry of the compensatory strategies adopted by the two dyslexic subtypes.     

阈下说服的存在证据与争议

通过阈下刺激或者信息的呈现, 试图引导个体采用某种观点、态度或者行为的过程被称为阈下说服。已有的研究从不同视角考察了阈下说服的效果, 对阈下说服的存在与否有着较大的争议。出现争议的原因可能与觉知、阈下语义激活、当前动机以及习惯有关。最近的研究聚焦于探究当前动机在阈下说服研究中所起到的关键作用。未来应当继续尝试其它途径, 促进语义激活; 丰富动机种类, 探讨引发动机的方法; 关注机体变量, 探索新机制。     

文字加工中的正字法家族效应

正字法家族效应是指正字法邻近词越多, 家族越大, 单词识别越快的一种现象。一般使用词汇判断、语义分类任务、快速命名等实验范式研究。影响家族效应的因素有家族词的频率、材料的语言和家族在单词中的位置等。家族效应表现在150~300ms窗口中的早期成分和更大的N400上。家族效应可能与左大脑半球的不同脑区的的语义激活有关, 也可能与中背外侧前额的执行控制功能有关。家族效应的理论模型主要有：多重标准识别模型、交互激活模型和双通路瀑布式模型等。将来的研究可尝试从实验材料和研究方法等方面进行拓展。     

情绪生理机制研究的外周与中枢神经系统整合模型

阐明人类情绪的生理机制是心理学家和神经科学家所面临的巨大挑战。以往研究倾向于分别考察情绪的外周反应模式和脑机制。近年来,随着情绪电生理学和认知神经科学的发展,许多研究者从外周与中枢神经系统相互作用的角度,提出了一些解释情绪生理机制的整合模型。其中,以情绪环路模型和神经内脏整合模型为典型代表。前者强调由外周到中枢的自下而上的加工方式,试图说明情绪经验形成的机制;后者则采取由中枢到外周的自上而下的加工方式,试图阐明情绪调控的机制。今后的研究有必要借鉴这两个模型,并结合近期有关情绪信息加工神经机制的新成果,以便构建能够更为全面解释人类情绪的生理模型。     

Trait BIS predicts alpha asymmetry and P300 in a Go/No‐Go task

Inspired by the revised Behavioural Inhibition System (BIS) theory the present study probed the association between individual differences in Trait BIS and electroencephalogram indicators of conflict processing/inhibition. Sixty‐nine male participants either high or low in Trait BIS completed a Go/No‐Go task while the electroencephalogram was recorded. As expected, Trait BIS was associated with the No‐Go‐anteriorisation of the P300 event‐related potential (i.e. an index of response inhibition presumably generated in the dorsal anterior cingulate—an area implicated in conflict processing) and with No‐ Go‐related changes towards left frontal alpha activity (i.e. presumably more activity in right prefrontal cortex—an area implicated in response inhibition). These findings support the role of conflict processing attributed to BIS functioning in the revised theory. Copyright © 2009 John Wiley & Sons, Ltd.     

An investigation of extreme responding as a mediator of cognitive therapy for depression

Although the efficacy of Cognitive Therapy (CT) for depression is well documented, questions remain about the conditions under which CT is maximally effective, and the mechanisms by which CT is efficacious. This study examined the role of extreme responding (ER) as a mediator and predictor of relapse, as well as a predictor of acute treatment outcome. To test mediation, ER of participants in CT was compared to ER of participants receiving Behavioral Activation (BA). Results indicated that ER was not a mediator of relapse in either condition. Both CT and BA showed reductions in depression severity, however neither group showed significant changes in ER over the course of treatment. Finally, ER did not predict or moderate acute treatment outcome. The implications of these results, strengths and limitations of the current study, and future research directions are discussed.     

Does Exposure and Response Prevention Behaviorally Activate Patients With Obsessive-Compulsive Disorder? A Preliminary Test

Exposure and response prevention (ERP) and behavioral activation (BA) are effective treatments for obsessive-compulsive disorder (OCD) and depression, respectively. Patients with OCD often exhibit depression; furthermore, ERP for OCD is associated with reduced depressive symptoms. To our knowledge, no study has examined whether ERP itself functions to behaviorally activate patients with concurrent OCD and depressive symptoms. This prospective study was designed to test the hypotheses that (a) OCD exposure hierarchy completion, increased BA, and depressive symptom reduction would all be related, and (b) pre- to posttreatment changes in BA would mediate the direct effect of OCD hierarchy completion on posttreatment depressive symptoms, even after controlling for pretreatment depressive symptoms, pretreatment BA, pre- to posttreatment reductions in OCD symptoms, treatment duration, and antidepressant medication use. Patients (N = 90) with a primary diagnosis of OCD who received residential ERP for OCD completed a self-report battery at pre- and posttreatment. Exposure hierarchy completion, increases in BA, and decreases in depression were all significantly correlated (rs ranged .33 to .44). The effect of hierarchy completion on posttreatment depressive symptoms was fully mediated by pre- to posttreatment changes in BA. Findings highlight the potential for ERP to exert antidepressant effects by behaviorally activating patients. Limitations, clinical implications, and future directions are discussed.     

Trajectories of Change in a Group Behavioral Activation Treatment for Severe,Recurrent Depression

Depression is a common and costly problem. Behavioral Activation (BA) is an effective treatment for depression when delivered 1:1, but group treatments often do not perform as well as 1:1 treatments. One way to begin to understand how group treatments perform is to assess the process of change during treatment. This study examined trajectories of change across 10-session group BA for individuals with severe, chronic, or recurrent forms of depression. We also tested whether individuals who had associated sudden gains or depression spikes had better outcomes than those who did not have these change patterns. We examined psychological and sociodemographic predictors of the patterns of change. Participants were 104 individuals who met diagnostic criteria for major depressive disorder and participated in one of 10 BA groups, provided over a 2-year period. A linear, but not quadratic or cubic, rate of change fit the data and the effect size for the change in mood symptoms from baseline to posttreatment was large, Cohen’s d = 1.25. Although 34% (26 of the 77 who provided outcome data) of individuals had a sudden gain and 10% (7/77) had a depression spike, neither sudden gains nor depression spikes predicted posttreatment outcomes. None of the demographic or psychological factors (rumination, behavioral activation) predicted the pattern of change. These results suggest that although group BA may help to reduce depressive symptoms in individuals with severe, recurrent, and/or chronic forms of depression, the overall linear pattern of change is different from quadratic patterns of change reported for 1:1 BA.     

汉语同形歧义词歧义消解的过程

实验采用启动范式,利用句子语境探讨同形歧义词（homographs）歧义消解的过程。结果表明：与语境一致的歧义词的主要意义首先得到通达,与语境一致的次要意义随后才被激活,与语境不一致的歧义词的意义没有得到激活,语境敏感模型可以较好地解释本实验的结果。