Spatial imagery of novel places based on visual scene transformation

The hippocampus is known to maintain memories of object-place associations that can produce a scene expectation at a novel viewpoint. To implement such capabilities, the memorized distances and directions of an object from the viewer at a fixed location should be integrated with the imaginary displacement to the new viewpoint. However, neural dynamics of such scene expectation at the novel viewpoint have not been discussed. In this study, we propose a method of coding novel places based on visual scene transformation as a component of the object-place memory in the hippocampus. In this coding, a novel place is represented by a transformed version of a viewer’s scene with imaginary displacement. When the places of individual objects are stored with the coding in the hippocampus, the object’s displacement at the imaginary viewpoint can be evaluated through the comparison of a transformed viewer’s scene with the stored scene. Results of computer experiments demonstrated that the coding successfully produced scene expectation of a three object arrangement at a novel viewpoint. Such the scene expectation was retained even without similarities between the imaginary scene and the real scene at the location, where the imaginary scenes only functioned as indices to denote the topographical relationship between object locations. The results suggest that the hippocampus uses the place coding based on scene transformation and implements the spatial imagery of object-place associations from the novel viewpoint.     

Online recognition of music is influenced by relative and absolute pitch information

Three experiments explored online recognition in a nonspeech domain, using a novel experimental paradigm. Adults learned to associate abstract shapes with particular melodies, and at test they identified a played melody's associated shape. To implicitly measure recognition, visual fixations to the associated shape versus a distractor shape were measured as the melody played. Degree of similarity between associated melodies was varied to assess what types of pitch information adults use in recognition. Fixation and error data suggest that adults naturally recognize music, like language, incrementally, computing matches to representations before melody offset, despite the fact that music, unlike language, provides no pressure to execute recognition rapidly. Further, adults use both absolute and relative pitch information in recognition. The implicit nature of the dependent measure should permit use with a range of populations to evaluate postulated developmental and evolutionary changes in pitch encoding.     

内隐与外显记忆编码阶段脑机制的重叠与分离

记忆包括编码和提取两个重要阶段, 以往研究多关注内隐和外显记忆在提取阶段的脑机制分离, 那二者在编码阶段的脑机制是否不同？为探讨这个问题, 该实验采用两阶段的迫选再认方式, 把学习项目区分成三类：随后被选择且告知为见过的项目(记住), 随后被选择但告知为猜测的项目 (启动)以及随后未被选择的项目(忘记)。结果表明, 从200 ms开始的颞区负走向Dm效应为内隐记忆(启动vs忘记)所特有, 反映了对刺激的知觉加工过程, 400~500 ms前额区正走向的Dm效应为外显记忆(记住vs忘记)所特有, 反映了对刺激的精细加工过程, 而200~300 ms中央区及600 ms开始的顶区负走向的Dm效应为两种记忆类型所共有, 它们分别反映了对刺激的注意状态以及把编码后的刺激信息登记进相应记忆系统的过程。因此, 内隐记忆与外显记忆在编码阶段的脑机制既存在着分离, 也存在着重叠的现象。     

创伤青少年自传体记忆具体性减少：情感调节还是执行控制受损

结合经典的自传体记忆测验(AMT)和反转-自传体记忆测验(AMT-R)探究创伤青少年自传体记忆具体性减少的原因。首先通过创伤事件终身经历问卷-学生版(LIET-S)和创伤后症状自评量表(CROPS)对630名青少年进行筛查, 然后结合访谈, 并采用儿童事件冲击量表-修订版(CRIES)测量创伤程度, 最终选取有创伤后症状的青少年63名, 分为高创伤组和低创伤组, 另无创伤经历的青少年30名作为控制组。三组被试均参加AMT和AMT-R实验。结果发现, 在AMT中, 创伤青少年表现出自传体记忆具体性减少的特点, 且创伤后症状越严重, 具体性减少越明显; 在AMT-R中, 创伤青少年提取的具体记忆数量与控制组无显著差异。结果表明, 创伤青少年自传体记忆具体性的减少是情感调节的结果。     

Association of polymorphisms in BDNF, MTHFR, and genes involved in the dopaminergic pathway with memory in a healthy Chinese population

The contribution of genetic factors to the memory is widely acknowledged. Research suggests that these factors include genes involved in the dopaminergic pathway, as well as the genes for brain-derived neurotrophic factor (BDNF) and methylenetetrahydrofolate reductase (MTHFR). The activity of the products of these genes is affected by single nucleotide polymorphisms (SNPs) within the genes. This study investigates the association between memory and SNPs in genes involved in the dopaminergic pathway, as well as in the BDNF and MTHFR genes, in a sample of healthy individuals. The sample includes 134 Taiwanese undergraduate volunteers of similar cognitive ability. The Chinese versions of the Wechsler Memory Scale (WMS-III) and Wechsler Adult Intelligence Scale (WAIS-III) were employed. Our findings indicate that the BDNF Met66Val polymorphism and dopamine receptor D3 (DRD3) Ser9Gly polymorphism are associated significantly with long-term auditory memory. Further analysis detects no significant associations in the other polymorphisms and indices. Future replicated studies with larger sample sizes, and studies that consider different ethnic groups, are encouraged.     

汉语为二语学习者言语产生中的跨语言干扰

采用跨语言长时竞争启动范式探讨汉语为二语学习者言语产生中的跨语言干扰。实验1的被试选择18名俄语为母语者, 实验2选择18名日语为母语者。自变量是命名语言(一语和二语)和学习条件(学过一致、学过不一致和未学过), 因变量是测验阶段被试图片命名的反应时和正确率。实验分为学习阶段和测验阶段, 被试分别用一语和二语命名图片, 观察被试在测验阶段学过一致与学过不一致两种条件下是否都能产生促进效应。实验结果发现, 无论俄语为母语者还是日语为母语者, 被试只有在学过一致条件下的反应时显著快于未学过条件, 而学过不一致条件下的反应时跟未学过没有显著差异。本研究结果表明, 汉语为二语学习者言语产生中存在跨语言干扰, 且语言间书写特征的差异对跨语言干扰没有影响。     

工作记忆对时间加工的影响

非时间信息加工与时间加工的关系是复杂的, 存在双向干扰或单向干扰, 结果的不一致与任务所需的注意资源及工作记忆都有关。工作记忆的中央执行系统在时间加工中起主要作用, 同时进行的非时间任务对中央执行功能的需求越多, 两种任务之间的干扰程度越大。语言环和视空间模板对时间加工的影响与非时间信息的类型有关。工作记忆作为一个整体以工作记忆容量为指标, 计时成绩也表现出与工作记忆容量有关的年龄、智力等方面的差异。时间加工和工作记忆在额叶、顶叶、基底神经节等皮质存在共同的神经机制。未来应该丰富工作记忆的研究内容, 结合时间加工的分段性探讨工作记忆影响时间加工的具体进程及神经机制, 并力求在应用方面取得一定的成果。     

任务数量与工作记忆容量对交错学习的影响

研究以分子结构式为材料,让被试在单任务或双任务条件下以集中呈现和交错呈现的方式进行学习,并通过操作广度、旋转广度和对称广度任务测量工作记忆容量（working memory capacity, WMC）,探究在基于规则类别学习中交错呈现优势的稳定性。结果显示,交错呈现优势仅体现在文科生中;而对于理科生,集中呈现效果较佳。另外,任务数量和WMC均不影响交错呈现优势,表明交错呈现优势稳定存在于单任务和双任务条件中,且不同WMC的个体均能从交错学习获益。     

现实场景典型空间位置关系客体的解码效应

通过探讨典型空间关系客体对中单个客体的视觉工作记忆,考察空间位置关系的解码特征和主动客体记忆优势。结果发现：（1）当客体以符合空间位置关系方式呈现时,记忆更准确;（2）符合空间位置关系条件下单个客体提取反应时更长,上方客体反应时更短,记忆更准确;（3）兼具空间位置关系与动作关系客体对中的主动客体记忆正确率更高。结果表明,现实场景客体空间分组中单个客体提取时存在解码现象和顺序效应,对现实中的上方与主动客体存在加工偏好。     

Dorsolateral prefrontal cortex mediates working memory processes in motor skill learning

Neuroimaging studies have shown that the dorsolateral prefrontal cortex (DLPFC) is recruited during motor skill learning, which suggests the involvement of the DLPFC in working memory (WM) processes, such as selection and integration of motor representations temporarily stored in WM. However, direct evidence linking activation of the DLPFC to WM storage and manipulation during motor skill learning in real-time is rare. In this study, we conducted two experiments to investigate the causal role of DLPFC activity in WM storage and manipulation during motor skill learning under low and high WM-demand conditions. Participants received continuous theta burst stimulation (cTBS) and sham stimulation (crossover design) over the left DLPFC (experiment 1) or right DLPFC (experiment 2). Before and after stimulation, participants in both experiments performed a sequential finger-tapping (SFT) task containing repeated sequence (low-WM demand) and non-repeated sequence (high-WM demand) conditions which are used to study WM processes. The number of correct sequences (NoCS) and reproduction error rate were analyzed. Learning gains in NoCS improved significantly with the practice for both sequence types in the presence of either stimulation type. Compared to sham stimulation, cTBS over the left DLPFC resulted in significantly reduced learning gains in NoCS for non-repeated sequences. These results suggest that the left DLPFC contributes to WM manipulation during motor skill learning.