A randomized controlled trial of the effect of D-cycloserine on extinction and fear conditioning in humans

Previous research has shown that D-cycloserine (DCS) facilitates extinction of Pavlovian fear conditioning in rats and enhances exposure therapy in humans. The aim of this study was to test the effect of DCS on extinction of fear conditioning in humans. In three experiments, 238 participants were given either DCS (50 or 500 mg) or placebo 2-3 h before extinction training following a differential shock conditioning paradigm. Clear extinction and recovery (return of fear) effects were observed on both skin conductance and self-reported shock expectancy measures in three studies. DCS had no influence on these effects. The same pattern was observed when the analysis was restricted to aware participants or to good conditioners, when fear-relevant cues (pictures of snakes) were used as the conditioned stimuli, or when analysis was restricted to heightened snake-fearful participants. These results suggest that DCS may not enhance the extinction, or prevent the recovery, of learned fear in a differential Pavlovian conditioning paradigm in humans. Further experimental research is needed to better understand the mechanisms underlying the therapeutic effects of DCS.     

Are Asians forgetful? Perception, retention, and recall in episodic remembering

Cross-cultural studies have shown that Asians exhibit less accessibility to episodic memories than Euro-Americans. This difference is often attributed to differential cognitive and social influences on memory retention, although there have been no empirical data concerning the underlying mechanism. Three studies were conducted to examine encoding and retention processes that may underlie the cultural difference in episodic recall. While Asians recalled fewer personal event episodes than Euro-Americans across different retention intervals, the two groups showed similar forgetting functions over time (Study 1). Asians also recalled fewer episodes of fictional events than Euro-Americans when the retention interval was kept to a minimum (Study 2). Finally, Asians perceived fewer discrete episodes than Euro-Americans when reading events in a narrative text (Study 3). Collectively, these findings suggest that the cultural difference in episodic recall may not be a mere consequence of memory retention but culture-specific perceptual processing and encoding. They have great theoretical, developmental, and clinical relevance.     

记叙文中时间信息的事件边界效应

运用视知觉研究中经典的事件切割程序,探讨记叙文中时间信息的事件边界效应.结果发现记叙文中的时间信息会被读者外显地知觉为事件边界,并且,跨度长的时间信息比跨度短的时间信息更易于被知觉为事件边界.这和视知觉研究中的发现是一致的.研究在一定程度上支持了记叙文理解过程中情境模型建构的过程依赖类似于事件知觉中所发现的切割过程的观点,为知觉研究和认知研究领域提供了可供沟通的实证支持.     

The metamorphosis of the statistical segmentation output: Lexicalization during artificial language learning

This study combined artificial language learning (ALL) with conventional experimental techniques to test whether statistical speech segmentation outputs are integrated into adult listeners’ mental lexicon. Lexicalization was assessed through inhibitory effects of novel neighbors (created by the parsing process) on auditory lexical decisions to real words. Both immediately after familiarization and post-one week, ALL outputs were lexicalized only when the cues available during familiarization (transitional probabilities and wordlikeness) suggested the same parsing (Experiments 1 and 3). No lexicalization effect occurred with incongruent cues (Experiments 2 and 4). Yet, ALL differed from chance, suggesting a dissociation between item knowledge and lexicalization. Similarly contrasted results were found when frequency of occurrence of the stimuli was equated during familiarization (Experiments 3 and 4). Our findings thus indicate that ALL outputs may be lexicalized as far as the segmentation cues are congruent, and that this process cannot be accounted for by raw frequency.     

Learning to love the older consumer

This paper examines how and why marketing has largely ignored the older consumer and concentrated on younger targets. It explores some of the myths of the older consumer and through examining recent research in the USA and the UK makes a plea for accepting the older consumer as still very much in the main stream of marketing. It also explores how society constructs age and how older people may wish to see themselves. While age related myopia is unsatisfactory for both consumers and marketing, older consumers may express a wide range of identities, making them a potentially complex target for marketing. The paper suggests that more research is needed to explore the different motives and identities of these important consumers with a view to better meeting their needs in terms of appropriate products, messages and media. Copyright © 2001 Henry Stewart Publications.     

词切分对初学者句子阅读影响的眼动研究

采用EyeLink II眼动仪,以72名小学三年级学生为被试,通过三个实验来探讨词切分对初学者汉语句子阅读的影响。实验一设置四种空格呈现条件:正常的无空格条件、字间空格条件、词间空格条件和非词空格条件。实验二采用灰条标记作为字、词或非词的边界,使不同条件下句子的空间分布是一致的。实验三进一步操纵了学生的阅读技能。结果发现三个实验的结果趋势是一致的。小学三年级学生在阅读有词间空格的文本和正常的无空格文本一样容易。尽管词切分文本对阅读技能高和阅读技能低的学生来说一样容易,但非词空格呈现条件会对阅读技能低的学生产生更大的干扰作用。阅读技能低的学生在阅读过程中更依赖于文本的低水平视觉线索。文章最后讨论了词切分对建构中文阅读眼动控制模型的启示。     

Probing the influence of unconscious fear-conditioned visual stimuli on eye movements

Efficient threat detection from the environment is critical for survival. Accordingly, fear-conditioned stimuli receive prioritized processing and capture overt and covert attention. However, it is unknown whether eye movements are influenced by unconscious fear-conditioned stimuli. We performed a classical fear-conditioning procedure and subsequently recorded participants’ eye movements while they were exposed to fear-conditioned stimuli that were rendered invisible using interocular suppression. Chance-level performance in a forced-choice-task demonstrated unawareness of the stimuli. Differential skin conductance responses and a change in participants’ fearfulness ratings of the stimuli indicated the effectiveness of conditioning. However, eye movements were not biased towards the fear-conditioned stimulus. Preliminary evidence suggests a relation between the strength of conditioning and the saccadic bias to the fear-conditioned stimulus. Our findings provide no strong evidence for a saccadic bias towards unconscious fear-conditioned stimuli but tentative evidence suggests that such an effect may depend on the strength of the conditioned response.     

Is There Savings for Pavlovian Fear Conditioning after Neurotoxic Basolateral Amygdala Lesions in Rats?

Considerable evidence indicates an important role for amygdaloid nuclei in both the acquisition and expression of Pavlovian fear conditioning. Recent reports from my laboratory have focused on the impact of neurotoxic lesions of the basolateral complex of the amygdala (BLA) on conditional freezing behavior in rats. In these studies, I have observed severe effects of posttraining BLA lesions on the expression of conditional freezing even after extensive presurgical overtraining (25-75 trials). Moreover, I have found no evidence for sparing of fear memory (i.e., savings) in these rats when I assess their rate of reacquisition relative to BLA rats receiving minimal training (1 trial). In these experiments, freezing behavior was assessed using a conventional time-sampling procedure and expressed as a response probability. Although this measure is well established in the literature, it is conceivable that it is not sensitive to spared memory in rats with BLA lesions. To address this issue, I present a more detailed analysis of freezing behavior that quantifies latency to freeze, the number of freezing bouts, the duration of freezing bouts, and the probability distribution of bout lengths. I also include control data from untrained (no-shock) rats. Consistent with my earlier reports, I find no evidence of savings of fear memory in rats with neurotoxic BLA lesions using several measures of freezing behavior. These results reiterate the conclusion that fear memory, as it is expressed in freezing behavior, requires neurons in the BLA.     

时间对犯罪隐藏信息记忆的影响

记录模拟犯罪者和阅读报纸后对案件知情的无辜者接受隐藏信息测试时的皮肤电活动,探讨时间对犯罪隐藏信息记忆的影响。结果发现：(1)延迟条件下,模拟犯罪组的再认率和皮肤电活动变化显著高于知情无辜组,但两组在立即条件下无差异;(2)知情无辜组在延迟条件下的甄别率显著低于立即条件下,而模拟犯罪者在两种条件下无差异。结果表明,延迟测试比立即测试更容易区分模拟犯罪组和知情无辜组;犯罪甄别率在延迟条件下减少,但也减少了知情无辜者被判断为犯罪者的风险。