Specificity of episodic and semantic aspects of autobiographical memory in relation to symptoms of posttraumatic stress disorder (PTSD)

Two studies examined the relationship between the ability to access specific autobiographical material in memory and presence/symptoms of posttraumatic stress. In Study 1, a sample of refugees with a diagnosis of posttraumatic stress disorder (PTSD) completed the Autobiographical Memory Test (AMT) in which they had to generate specific episodic autobiographical memories in response to emotion-related cue words. Results showed that reduced specificity of memories on the AMT was associated with an increased frequency of trauma-related flashbacks but with reduced use of effortful avoidance to deal with trauma-related intrusions in the day-to-day. Study 2 examined retrieval of semantic autobiographical information from previous lifetime periods in groups of cancer survivors with posttraumatic stress and healthy controls. The cancer survivors were able to generate fewer specific semantic details about the personal past compared to the controls. The more symptomatic survivors showed the greatest memory impairment. The data from both studies are discussed in terms of compromised access to specific autobiographical material in distressed trauma survivors reflecting a process of affect regulation.     

Enhanced recognition of emotional stimuli in the chimpanzee (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)

Humans often have a better memory of emotional events than neutral events. From the comparative-cognitive perspective, we explored the enhancement of recognition memory by emotion in chimpanzees (Pan troglodytes) using a serial probe recognition task. In this task, we sequentially presented a list of pictures to subjects and then tested their recognition of specific pictures from within the list. We selected pictures of aggressive chimpanzees as emotional stimuli and less tensed, relaxed chimpanzees as neutral stimuli. In Experiment 1, we gave four-item lists to two young chimpanzees; one showed significantly greater recognition of pictures depicting aggressive chimpanzees than neutral ones. In Experiment 2, this chimpanzee was further tested using a recognition task with eight-item lists. The subject again showed better recognition of emotional stimuli than neutral. Furthermore, the presence of an emotional stimulus in the list also facilitated recognition of the neutral item immediately following it. Overall, although only one of the two chimpanzees showed enhanced recognition memory by emotional stimuli, this is the first demonstration of such a response in the chimpanzee. The findings are discussed in comparison with those of human studies.     

Visual working memory capacity for objects from different categories: a face-specific maintenance effect

The capacity of visual working memory was examined when complex objects from different categories were remembered. Previous studies have not examined how visual similarity affects object memory, though it has long been known that similar-sounding phonological information interferes with rehearsal in auditory working memory. Here, experiments required memory for two or four objects. Memory capacity was compared between remembering four objects from a single object category to remembering four objects from two different categories. Two-category sets led to increased memory capacity only when upright faces were included. Capacity for face-only sets never exceeded their nonface counterparts, and the advantage for two-category sets when faces were one of the categories disappeared when inverted faces were used. These results suggest that two-category sets which include faces are advantaged in working memory but that faces alone do not lead to a memory capacity advantage.     

视觉工作记忆中的加工与存储机制:回顾与思考

在视觉工作记忆的研究中,是否可能划分出视觉空间工作记忆和视觉物体工作记忆两个子系统还没有定论.子系统划分成立的基本前提是以特征为存储单位.当前关于存储单位的理论有特征理论、客体理论和双重存储等不同观点,多数视觉信息加工与存储机制的研究支持双重存储说.注意与视觉信息的加工和存储相互影响,因此,加工及存储机制的研究就要在具体的注意水平上进行.     

Aspects of Code-Specific Memory Development

We investigated the development of code specific representations of different kinds of information in long term memory. Forty second graders, 40 sixth graders and 40 adults learned the associations between 12 pictures and one position each in a 4 × 3 grid of squares, 12 pictures and 1 of 12 monosyllabic words each or 12 pictures and 1 of 12 faces. After a 3 min distractor task, a picture was presented in the retrieval phase, and the associated position, word or face had to be selected. Performance in the verbal condition improved as a function of age, while performance in the spatial condition turned out to be independent of age, and the performance in the facial condition showed a difference between both child groups and the adults. The results revealed a developmental difference of code specific representation of different kinds of information.     

遗忘症患者外显与内隐记忆分离的实验研究：自由回忆与再认任务

采用WMS－CR和MMSE筛选了9名遗忘症患者,采用自由回忆和再认两项任务观察了他们及正常对照组的外显记忆。结果发现：遗忘症患者两项外显记忆任务操作呈分离现象,自由回忆任务操作明显受损,再认任务的操作尽管较对照组低,但与对照组差异未达显著性水平。推论;①外显记忆受患者损伤的颞叶或间脑结构调节。②再认任务至少包含两种性质不同的潜在加工过程,一种为意识性重组加工,另一种为无意识自动加工,两者相互独立地贡献再认任务的操作。正常人意识性重组加工的贡献占优势,掩盖了无意识的作用。遗忘症患者意识性重组加工损伤,无意识自动加工部分代偿作用。③先前研究未对遗忘症患者进行认知功能的筛选,患者对再认障碍可能源于其他认知功能障碍,而非记忆障碍之故。     

Age-associated memory impairment—pathological memory decline or normal aging?

The aim of the study was to determine whether the memory capacity of individuals with age-associated memory impairment (AAMI) over a period of approximately 3½ years declines more, if at all, than the memory capacity of persons without AAMI. Four computerized and three non-computerized memory tests, a naming test, and a test of visuo-motor speed were administered twice. Two estimates of intellectual capacity were made, one at the first examination and the other 3½ years later. One person in the AAMI group (n=44) developed vascular dementia. The group of AAMI subjects did less well on two of the seven memory tests after 3½ years than they did initially; the control group (n=18) had lower scores on one memory test at follow-up than they had previously. The data suggest that the memory capacity of subjects with AAMI is not pathologically impaired. The general intellectual level significantly influences whether an individual with memory complaints will be classified AAMI or not. People with high intelligence are less likely than people with lower intellectual capacity to fulfill the AAMI criteria. This suggests that AAMI lacks in construct validity.     

The link between knowledge and remembering in Alzheimer’s disease

Current research on the influence of cognitive support (e.g., activation of task-relevant prior knowledge, item organizability, retrieval cues) on episodic remembering in normal aging and Alzheimer’s disease (AD) is reviewed. Examining the effects of cognitive support on memory may shed light on the relationship between knowledge and remembering, and also provides relevant information pertaining to the development of cognitive intervention procedures. A series of studies from our own and other laboratories reveal a number of interesting empirical regularities. First, AD results in problems in utilizing cognitive support for improving memory. Conceivably, this reduction in cognitive reserve capacity is due to both the overall severity of the episodic memory impairment in AD, as well as to dementia-related deficits in the semantic network that guides encoding and retrieval of information. Nevertheless, AD patients are able to utilize cognitive support in episodic memory tasks, although they typically need more support than their healthy aged counterparts to show memory facilitation. Specifically, it is critical to provide support at both encoding and retrieval in order to demonstrate performance gains in AD. Moreover, successful utilization of retrieval support in this disease is most likely to occur when the encoding requirements force the individual to engage in elaborative cognitive activity (e.g., generation of task-relevant knowledge, categorical organization). Finally, a reduction in cognitive reserve capacity occurs later in the pathogenesis of AD than a generalized episodic memory impairment. This observation reflects the insidious nature of AD, and suggests that the transition from normal aging to AD may be continuous rather than discrete.     

学习困难儿童在工作记忆任务中抑制机制的研究

本研究的目的旨在探讨在WM任务中,LD儿童是否存在抑制机制缺陷。实验程序采用重复启动范式,设计“预期”和“目标”两种启动条件,随后通过间接测量的方式(内隐记忆测验)分别测得LD儿童和NLD儿童对预期词和目标词的启动量。结果表明,LD儿童对预期词的启动分数与目标词没有显著差异,NLD儿童对目标词的启动分数显著高于对预期词的启动分数。我们得出结论:在工作记忆任务中,LD儿童存在抑制机制缺陷。     

工作记忆对类比推理的影响

该实验采用2(类比推理类型)×6(组别)双因素实验设计来探讨工作记忆与类比推理之间的关系,尤其关注工作记忆的各个子成分对类比推理的影响。控制组的被试只需完成类比推理测验,而实验组的被试是在双任务的条件下进行实验。结果表明,工作记忆是影响类比推理的一个重要因素。在图形类比推理中,主要有视空间模板中的空间成分,语音回路中的发音成分以及中央执行器的参与;在言语类比推理中,则是视空间模板中的空间成分起主要作用。