基于气味的自传体记忆提取时间分析

为检验普鲁斯特效应提取是否存在气味辨别确定的决策阶段,在实验一和实验二中分别以气味、气味词和不同辨认度的气味为线索,设置干扰任务,考察自传体记忆基于气味线索回忆的提取时间差异。实验一发现,语词标签和气味不一致条件,自传体记忆提取时间出现干扰效应,而气味一致条件未出现。实验二发现,难、易辨认度气味均有干扰效应。表明普鲁斯特效应提取存在气味辨别确定的决策阶段,它是气味本身和气味辨别确定所激活的气味语义表征促进了自传体记忆提取的“双加工”机制。     

Primate prefrontal neurons encode the association of paired visual stimuli during the pair-association task

The prefrontal cortex (PFC) is known to contribute to memory processes such as encoding representations into long-term-memory (LTM) and retrieving these representations from LTM. However, the details of the PFC's contribution to LTM processes are not well known. To examine the characteristics of the PFC's contribution to LTM processes, we analyzed single-neuron activity while monkeys performed a pair-association (PA) task using 12 pairs of complex visual images. Among 60 neurons with sample-period activity, 32% showed the strongest and second-strongest sample-period activities when a particular pair of stimuli was presented (pair selectivity). In addition, the mean latency of sample-period activity was 138 ms in the PFC, which was longer than that observed in ITC neurons under bottom-up conditions, but shorter than that under top-down conditions. These results indicate that the PFC participates in encoding and retrieving information in LTM processes and that pair-selective sample-period activity might be a candidate for the top-down signal that the PFC provides to the ITC during the retrieval of information from LTM.     

The contribution of category‐based and contextual suppression towards retrieval‐induced forgetting1

Abstract: This study examines whether both context‐related and category‐related memory impairment can be found using a retrieval‐induced forgetting procedure. One group of participants was tested using a standard retrieval‐practice paradigm, whereas for the no‐practice group the retrieval practice was replaced by irrelevant filler activity. The results showed that the within‐participant baseline items were recalled more poorly by the practice group than by the no‐practice group, whereas the practice group showed the standard retrieval‐induced forgetting effect. Thus, retrieval practice impaired recall for both within‐category and baseline items, although it impaired the former to a greater extent. This finding suggests that it is necessary to consider not only categorical relationships between items, but also context information shared by items when exploring retrieval‐induced forgetting.     

Retrieval practice can improve classroom review despite low practice test performance

Review is often more effective when it involves deliberate memory retrieval. However, this advantage may depend on a high rate of retrieval success; students who are less capable with the material may be better served by another activity. In our study, year 9 geography students listened to factual information, then reviewed some of it with a retrieval practice and feedback activity, some with a reading activity and left some unreviewed. We also manipulated the presence of hints during review—hints can affect the rate of retrieval success during practice and are relatively easy for teachers to provide. When tested 1 week later, most students showed a benefit of retrieval practice, even those who had performed poorly during review. There was also some evidence that hints improved learning when they made retrieval practice easier. Our findings suggest that retrieval practice, properly implemented, is advantageous for students of all ability levels.     

Direct and generative autobiographical memory retrieval: How different are they?

Theories of autobiographical memory have emphasised effortful generative retrieval, but recent research indicates that subjectively effortless direct retrieval is common. We compared the processes of direct and generative retrieval. Sixty-five participants retrieved 24 autobiographical memories across three cue types: concrete, emotional, and personal. We recorded retrieval latency, and participants judged direct versus generative retrieval and rated memory specificity, vividness, significance, rehearsal, and emotionality. Overall, direct retrieval was common, especially for personal cues. Directly retrieved memories were recalled faster, were less likely to be specific, and were rated more significant, rehearsed, and emotional than generatively retrieved memories. The speed of both direct and generative retrieval varied similarly according to cue type, suggesting they did not involve fundamentally different cognitive processes. These findings challenge theories that assume direct retrieval bypasses constructive processes. Instead we suggest that both direct and generative retrieval involve construction that is similarly affected by cue concreteness and relevance.     

Neural activity reveals effects of aging on inhibitory processes during word retrieval

Word retrieval difficulties are one of the most frustrating problems for older adults. Poorer access to phonological representation of the target word has been postulated as the underlying deficit, supported by findings of improved word retrieval after phonological priming. To better understand aging effects in the underlying neurophysiology associated with word retrieval, this study examined electrophysiological correlates of phonological priming and word retrieval in adults. Young, middle-aged, and older adults viewed pictures that were preceded by pseudo-word primes that either shared initial phonemes with or were unrelated to the picture’s name. Participants made phonological judgments regarding the prime and picture prior to naming the picture. Behavioral and event-related potential correlates of phonological priming and word retrieval were recorded. All groups benefitted similarly from phonological priming, evidenced by faster phonological judgment response times and increased ease of word retrieval for primed pictures, indexed by the N400 priming effect. The peak latency of the N2, however, showed an incremental delay with age. High correlation between N2 peak latency and clinical measures of inhibition suggested an age-related delay in the inhibition of primed lexical competitors. Taken together, our results indicated intact activation of phonological representation of the picture’s name but age-related delays in inhibition of primed competitors. Interestingly, our findings revealed that delays in inhibiting lexical competitors may begin as early as middle age, highlighting the importance of including multiple age groups to better represent the aging trajectory.     

Recall cues interfere with retrieval from visuospatial working memory

Visuospatial working memory allows us to hold multiple visual objects over short delays. It is typically tested by presenting an array of objects, then after a delay showing a ‘probe’ indicating which memory item to recall or reproduce by adjusting a target feature. However, recent studies demonstrate that information at the time of probe can disrupt recall. Here, in three experiments we test whether traditional memory probes, which contain features that compete with the feature to be recalled, may themselves interfere with performance. We asked participants to report the direction of one of the several coloured arrows in memory, based on its colour. First, we demonstrate that recall is better when the probe is initially just a coloured dot, rather than a coloured arrow which has to be adjusted to match orientation memory, consistent with interference from features of the probe itself. Second, this interference is present even when a mask follows the memory array, suggesting that the interference does not work by degrading immediate or iconic memory. Finally, when items are shown sequentially, the first and last items are invulnerable to probe interference. Our findings support recent theories of associative recall, in which probes reactivate features in WM, retrieving information by pattern completion.     

记忆机制中再认的事件相关电位

ERP对于记忆的研究有独到之处,在研究方法是有外显的直接范式和内隐的间接范式,分别表现为ERP新旧效应和重复效应,即在刺激200ms以后的正向偏移.对于记忆提取的ERP效应已有一些理论解释,但在听觉记忆、汉字记忆以及记忆的脑内机制等方面还需要进一步的深入研究.     

学习困难学生视空间工作记忆提取能力的多指标分析

本实验设计高、低两种加工负载的视空间WM作业,采用WM广度、提取错误值和提取速度三项指标评估学困生视空间WM的提取能力,比较学困生和学优生视空间WM的提取能力间的差异。结果表明：无论在低加工负载条件下还是在高加工负载条件下,学困生视空间WM的提取能力都比学优生差。在不同加工负载条件下,三项指标对评估学困生和学优生视空间WM提取能力间差异的重要程度不同。低加工负载条件下WM容量和提取错误值是较好的指标,而高加工负载条件下WM容量和提取速度是较好的指标。     

Cognitive neuroscience of aging: contributions of functional neuroimaging

By revealing how brain activity during cognitive performance changes as a function of aging, studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) are contributing to the development of a new discipline of Cognitive Neuroscience of Aging. This article reviews functional neuroimaging studies of cognitive aging in the domains of visual perception, episodic memory encoding and semantic memory retrieval, episodic memory retrieval, implicit memory, and working memory. The most consistent finding of these studies was that brain activity tends to be less lateralized in older adults than in younger adults. This finding is conceptualized in terms of a model called Hemispheric Asymmetry Reduction in Old Adults (HAROLD). According to a compensation hypothesis, bihemispheric involvement could help counteract age-related neurocognitive decline, whereas, according to a dedifferentiation hypothesis, it reflects a difficulty in recruiting specialized neural mechanisms.