视觉工作记忆负载对偏差干扰调控的ERP研究

采用事件相关电位技术（ERPs）,对听视跨通道不同工作记忆负载下偏差干扰效应的加工机制进行研究。当视觉线索50%时,比较有无工作记忆负载条件下偏差干扰效应,分析偏差刺激与标准刺激诱发的差异波,结果发现：（1）存在工作记忆负载和偏差干扰效应;（2）有无工作记忆负载下差异波均出现明显的N1/MMN成分、NP3和RON成分;（3）差异波中N1/MMN成分的平均波幅和潜伏期均没有差异,NP3成分的平均波幅下降;RON成分在平均波幅上没有差异,潜伏期上有工作记忆负载下显著小于无工作记忆负载。研究表明视觉工作记忆负载对偏差干扰调控过程的神经机制并不会因为无关信息与相关信息间冲突竞争增强而改变。     

记忆集对注意焦点转换及其返回抑制的影响

采用记忆更新任务,实验1要求被试分别更新3个和4个记忆项目,并设置不转换、控制转换和抑制转换条件,考察记忆集对注意焦点转换及其返回抑制的影响;实验2操纵两次更新同一记忆项目之间对其它记忆项目更新的次数（2次、3次及3次以上）,在实验1基础上,考察返回抑制中项目抑制状态的消退过程.结论：随记忆集增加,转换代价增大,而返回抑制效应消失;当注意焦点对其它记忆项目更新2次时,之前被抑制项目的抑制状态可完全消退.     

Visual attribute modulates the time course of iconic memory decay

Studies on iconic memory demonstrate that rich information from a visual scene quickly becomes unavailable with the passage of time. The decay rate of iconic memory refers to the dynamics of memory availability. The present study investigated the iconic memory decay of different stimulus attributes that comprised an object. Specifically, in Experiment 1, participants were presented with eight coloured numbers (e.g., red 4) and required to remember only one attribute, either colour or number, over different blocks of trials. The participants then reported the cued attribute in which the cue Stimulus Onset Asynchrony (SOA) from the memory array onset was varied (0, 100, 200, 300, 500, and 1000?ms). We found that numerical information became unavailable more quickly than colour information, despite the fact that the memory accuracies at 0 and 1000?ms SOAs were comparable between the two attributes. In Experiment 2, we replicated the finding that a numerical representation was lost more quickly than a colour representation when visual masks followed the target stimulus. These results suggest that the various visual attributes comprising an object are lost over time at different rates in iconic memory. We discuss this finding in relation to how perceptual representation is transferred to the capacity-limited visual working memory.     

Object representations are biased toward each other through statistical learning

The visual system is remarkably efficient at extracting regularities from the environment through statistical learning. While such extraction has extensive consequences on cognition, it is unclear how statistical learning shapes the representations of the individual objects that comprise the regularities. Here we examine how statistical learning alters object representations. In three experiments, participants were exposed to either random arrays containing objects in a random order, or structured arrays containing object pairs where two objects appeared next to each other in fixed spatial or temporal configurations. After exposure, one object in each pair was briefly presented and participants judged the location or the orientation of the object without seeing the other object in the pair. We found that when an object reliably appeared next to another object in space, it was judged as being closer to the other object in space even though the other object was never presented (Experiments 1 and 2). Likewise, when an object reliably preceded another object in time, its orientation was biased toward the orientation of the other object even though the other object was never presented (Experiment 3). These results demonstrated that statistical learning fundamentally shapes how individual objects are represented in visual memory, by biasing the representation of one object toward its co-occurring partner. Importantly, participants in all experiments were not explicitly aware of the regularities. Thus, the bias in object representations was implicit. The current study reveals a novel impact of statistical learning on object representation: spatially co-occurring objects are represented as being closer in space, and temporally co-occurring objects are represented as having more similar features.     

Universal stories: How narratives satisfy core motives

Abstract

For millennia, narratives have been a primary mode of oral discourse. Narrative presentation of information has been shown to facilitate interpersonal and group communication. However, research indicates that narratives are more than merely an adaptive mode of communication. Narrative is a fundamental – and perhaps foundational – element of social and cultural life. The present article posits that the centrality of narrative in social life is due to narrative’s ability to help satisfy the five core social motives, as identified by Fiske belonging, understanding, control, self-enhancement, and trust. In so doing, this article reviews empirical and theoretical work examining basic narrative processes, autobiographical narratives, and entertainment narrative consumption to illustrate how narrative thought helps to satisfies core human motives and in turn, how the narrative construction process informs self and identity formation.     

On using what we know about ourselves in thinking about others: Not so fast

Abstract

We argue that the frequently assumed privileged role of the self as a habitual reference point in social judgments is often hindered by the fact that, unlike other persons, the self is typically represented primarily in terms of internal, unobservable characteristics. This idiosyncratic feature of self-representations may render them incompatible with many other social representations. Yet, such limitations are not universal. In particular, incompatibility is less of a problem when (1) the judgment target is someone psychologically close; (2) accessible self-representations involve distant (rather than recent) self-memories; (3) accessible self-representations are relatively abstract, (semanticized) rather than event-specific; or, (4) social judgements concern not a specific other person but more abstract social concepts such as traits.     

Augmenting treatment efficiency in exposure therapy for PTSD: a randomized double-blind placebo-controlled trial of yohimbine HCl

The alpha-2 adrenergic receptor antagonist, yohimbine, can facilitate fear extinction in animals and humans. One potential mechanism is increased noradrenergic activity and associated arousal in the presence of conditioned stimuli. Accordingly, yohimbine might augment prolonged exposure (PE) therapy for posttraumatic stress disorder (PTSD), where heightened exposure-oriented arousal is a theorized driver and empirical predictor of treatment success. A double-blind placebo-controlled randomized trial (NCT 01031979) piloted yohimbine augmentation in 26 males with combat-related PTSD. Participants were given one-time dose of yohimbine or placebo prior to the first imaginal exposure. Subsequently, both arms completed standard PE. The primary outcome was trauma-cued heart-rate reactivity a week after the drug/exposure visit, a highly specified, objective measure sensitive to incremental change. Secondary outcomes included arousal during the drug/exposure visit and slope of distress, PTSD, and depression over the course of PE. Consistent with hypothesis, yohimbine led to higher objective and subjective arousal during the drug/exposure visit and to lower trauma-cued heart-rate reactivity one-week later. One dose of yohimbine also led to greater between-session habituation and more rapid improvement on depression, but not PTSD, over the course of care. Results of this controlled pilot indicate support for continued investigation of yohimbine-augmented exposure therapy for PTSD.     

Positive memory enhancement training for individuals with major depressive disorder

When in a negative mood state, individuals with major depressive disorder (MDD) may have difficulties recalling positive autobiographical memories in a manner that repairs that negative mood. Using cognitive bias modification techniques, investigators have successfully altered different aspects of cognition among individuals with MDD. However, little has been done to investigate the modification of positive autobiographical memory recall. This study examined the impact of a novel positive memory enhancement training (PMET) on the memories and subjective affective experiences of individuals with MDD (N = 27). Across a series of trials, participants first recalled a sad memory to elicit a negative mood state. They then recalled a happy memory and completed procedures to elicit a vivid, here-and-now quality of the memory. PMET procedures were hypothesized to promote mood repair via the recall of increasingly vivid and specific positive memories. PMET participants demonstrated improved memory specificity and greater perceived ability to “relive” positive memories. The procedures also repaired mood; PMET participants’ affect following recall of positive memories did not differ from control participants’ affect following recall of neutral memories. Results provide preliminary support for PMET as a method to improve the quality of positive memories and facilitate emotion regulation in MDD.