Increasing top-down suppression from prefrontal cortex facilitates tactile working memory

Navigated transcranial magnetic stimulation (TMS) combined with diffusion-weighted magnetic resonance imaging (DW-MRI) and tractography allows investigating functional anatomy of the human brain with high precision. Here we demonstrate that working memory (WM) processing of tactile temporal information is facilitated by delivering a single TMS pulse to the middle frontal gyrus (MFG) during memory maintenance. Facilitation was obtained only with a TMS pulse applied to a location of the MFG with anatomical connectivity to the primary somatosensory cortex (S1). TMS improved tactile WM also when distractive tactile stimuli interfered with memory maintenance. Moreover, TMS to the same MFG site attenuated somatosensory evoked responses (SEPs). The results suggest that the TMS-induced memory improvement is explained by increased top-down suppression of interfering sensory processing in S1 via the MFG-S1 link. These results demonstrate an anatomical and functional network that is involved in maintenance of tactile temporal WM. (C) 2009 Elsevier Inc. All rights reserved.

Dissociation of egocentric and allocentric spatial processing in prefrontal cortex

Monkeys with lesions of areas 9 and 46 performed three variants of the spatial delayed response (SDR) task. There were no impairments in allocentric spatial memory in which geometrical relationships between environmental cues were used to identify spatial location; thus, memory of a 3D environmental map is intact. In contrast, there were severe impairments in egocentric spatial memory guided by visual or tactile cues that monkeys can relate to their viewing perspective during testing. These results strongly suggest that dorsolateral prefrontal cortex selectively mediates spatial memory tasks that are solved by referencing the location of targets to the body's orientation. (C) 2003 Lippincott Williams Wilkins.

Ⅰ、新生期触觉刺激和短时间母婴分离经历对大鼠成年后学习记忆的影响 Ⅱ、银杏叶提取物对育亨宾所致大鼠空间工作记忆障碍的改善作用

本研究探讨了新生期的触觉刺激（tactile stimulation，TS）和母婴分离（maternal separation，MS）经历对大鼠成年后空间工作记忆和空间参考记忆的影响，以及对海马-前额叶神经通路的突触可塑性产生的效应。Wistar品系的母鼠分娩后，以split-litter方法对仔鼠进行分组：NTS组的仔鼠不接受触觉刺激和母婴分离；TS组的仔鼠在出生后第2-9天（postnatal day 2-9，PND2-9），或者PND10-17内，每天接受短暂（约30s）的人为抓握，并进行体表标记；TS/MS组的仔鼠在PND2-9，或者PND10-17内，接受TS组相同方式的抓握并在不同体表部位进行标记后，被单独地放入一个杯子中，杯中有取自鼠巢的垫料，每天与母鼠分离1h后返回鼠巢。按照常规方法饲养这些在新生期有不同经历的大鼠，待其成年后（3月龄），采用交互延缓作业（纠正错误法和不纠正错误法）、空间分辨作业及反转学习作业测试雄性大鼠的学习记忆功能，并观察多巴胺D1受体激动剂A77636对不同组成年雄鼠的工作记忆是否产生影响。采用活体电生理方法，高频刺激海马腹侧部在前额叶记录突触效能长时程增强（long-term potentiation，LTP），对PND2-9有不同经历的成年大鼠（雌雄兼用）的海马-前额叶LTP进行比较。 结果：（1）各组仔鼠间在PND30、PND60和PND90的体重都没有显著性差异，表明本研究中的新生期TS处理和MS处理不影响仔鼠的体重发育。 （2）在交互延缓作业-纠正错误法中，各组成年雄鼠在0s延缓期的达标天数没有显著性差异；0s延缓期达标后，再经过30天的训练，PND2-9TS组和PND10-17TS组的成年雄鼠达到的最长延缓期明显高于NTS组，而且在30s—50s延缓期内达标（正确率≥86.7%）的大鼠数量明显较多（与NTS组相比）。采用交互延缓作业-不纠正错误法，各组成年雄鼠在0s延缓期的训练成绩没有显著性差异，但是，PND2-9TS组和PND10-17TS组的成年雄鼠在40s延缓期的训练正确率明显高于NTS组，表明新生期的TS处理明显改善成年雄性大鼠成年后的空间工作记忆。 （3）各组成年雄鼠在空间分辨作业及反转学习作业中的成绩没有明显差异，表明新生期TS经历对雄鼠成年后空间学习记忆的影响是任务依赖性的：与前额叶有关的空间工作记忆功能比较容易受到新生期TS经历的影响，而空间参考记忆相对不容易受到新生期TS经历的影响。 （4）多巴胺D1受体激动剂A77636只有1个剂量（0.1mg/kg）对NTS组成年雄鼠的交互延缓作业成绩具有明显的改善效应。对PND2-9TS组成年雄鼠的交互延缓作业成绩，A77636的0.1mg/kg和1mg/kg剂量都具有明显改善效应。对PND10-17TS组成年雄鼠的交互延缓作业成绩，A77636的0.01mg/kg、0.1mg/kg和1mg/kg剂量都具有明显改善效应。与NTS组相比，A77636对这2个TS组成年雄性大鼠的有效改善剂量范围较宽，提示新生期TS处理经历对雄性大鼠成年后空间工作记忆的改善效应与其前额叶的多巴胺D1受体功能上调有关。 （5）与NTS组相比，PND2-9TS组雄性和雌性成年大鼠的海马-前额叶神经通路的LTP幅度都明显增加。由于海马-前额叶神经通路在空间工作记忆功能中起重要作用，新生期TS经历增强大鼠成年后的海马-前额叶神经通路的突触可塑性，为新生期TS经历增强大鼠成年后的空间工作记忆提供了电生理学的证据。TS成年大鼠海马-前额叶LTP增强可能与其前额叶的D1受体功能上调有关。 （6）本研究中，TS/MS组的新生期仔鼠在PND2-9或者PND10-17内，除了接受与TS组相同方式的抓握并在不同部位标记外，每天与母鼠分离1h，因此通过不同日龄段的TS/MS组与TS组的比较，拟对新生期MS处理的效应进行评估。结果发现，无论是对成年雄性大鼠的各项行为测试（空间分辨作业、交互延缓作业、A77636影响交互延缓作业的量效曲线），还是对成年雌性大鼠的行为测试（明/暗箱作业、一次性被动回避反应，论文Ⅱ），或者对海马-前额叶神经通路的LTP，新生期的MS处理对本研究中的所有测试指标在统计上都没有显著性的差异，说明新生期每天1h的母婴分离经历对大鼠成年后的学习记忆等行为及前额叶突触可塑性没有产生明显的影响，对前额叶D1受体功能也没有明显影响。 （7）对所有测试指标，本研究采用的2个仔鼠日龄段PND2-9和PND10-17之间的统计比较没有明显差异，提示PND2-9和PND10-17甚至整个泌乳期都是仔鼠神经系统对外界环境刺激比较敏感的发育关键期。 结论：新生期的触觉刺激经历改善雄性大鼠成年后的空间工作记忆，增强海马-前额叶神经通路的突触可塑性和前额叶D1受体功能；新生期短时间的母婴分离经历对大鼠成年后的空间工作记忆和前额叶突触可塑性等没有产生明显的影响，可能具有一定的生物学适应意义。

品牌表现评价反应时与关注特性的关系

The decision making of customers has been a great concern in the field of customer research. Although China has entered the era of brand consumption and development, due to the different understanding of the regarded attributes between companies and customers, the phenomenon of “The awarded products don’t sell well, but the products which sell well can’t get the award.” appears. At the same time there is little research on the relationship between the brand and the customers has been conducted in China now. Traditional research on customer psychology employ questionnaires, depth interview and group discussions as the major methods. In cognitive psychology, the limitation of explicit memory has been revealed by implicit memory; moreover, unconscious cognition and implicit memory can also influence customers' remark of the brand. Therefore, the traditional methods are not accurate enough. Reaction time is an effective way to reveal testing equality, and it can also reveal implicit cognition. Based on the researches intends to investigate the validity of attention attributes in the method of reaction time by questionnaires and time reaction testing of 360 customers in 3 cities, which may, probably, overcomes the limitation of the traditional research methods. The 352 valid samples were analyzed by SPSS. The results showed there was no distinct corresponding relationship between the product attributes and reaction time. The different key attributes from questionnaire importance rating and the shortest reaction time standards were used to regressively analyze the results of customers’ overall rating (such as overall satisfaction,objective quality, recommend intention).The results indicated that the coefficiency of regression of the special attributes chosen from reaction time to overall rating was distinct, while the coefficiency of the special attributes chosen from importance rating to overall rating was not. The main conclusions are: 1. Regarded attributes can be obtained by the reaction time of brand performance rating. 2. Regarded attributes obtained by the reaction time of brand performance rating are more accurate than those by importance rating questionnaires. 3. The brand’s core attributes should includes regarded attributes during the decision making process.

获取无意识结构知识的机制:主观熟悉感与刺激重复结构在人工语法学习中的作用

The nature of the distinction between conscious and unconscious knowledge is a core issue in the implicit learning field. Furthermore, the phenomenological experience associated with having knowledge is central to the conscious or unconscious status of that knowledge. Consistently, Dienes and Scott (2005) measured the conscious or unconscious status of structure knowledge using subjective measures. Believing that one is purely guessing when in fact one knows indicates unconscious knowledge. But unconscious structural knowledge can also be associated with feelings of intuition or familiarity. In this thesis, we explored whether phenomenological feelings, like familiarity, associated with unconscious structural knowledge could be used, paradoxically, to exert conscious control over the use of the knowledge, and whether people could obtain repetition structure knowledge. We also investigated the neural correlates of awareness of knowing, as measured phenomenologically. In study one, subjects were trained on two grammars and then asked to endorse strings from only one of the grammars. Subjects also rated how familiar each string they felt and reported whether or not they used familiarity to make their grammaticality judgment. We found subjects could endorse the strings of just one grammar and ignore the strings from the other. Importantly, when subjects said they were using familiarity, the rated familiarity for test strings consistent with their chosen grammar was greater than that for strings from the other grammar. Familiarity, subjectively defined, is sensitive to intentions and can play a key role in strategic control. In study two, we manipulated the structural characteristic of stings and explored whether participants could learn repetition structures in the grammatical strings. We measured phenomenology again and also ERPs. Deviant letters of ungrammatical strings violating the repetition structure elicited the N2 component; we took this to be an indication of knowledge, whether conscious or not. Strings which were attributed to conscious categories (rules and recollection) rather than phenomenology associated with unconscious structural knowledge (guessing, intuition and familiarity) elicited the P300 component. Different waveforms provided evidence for the neural correlates of different phenomenologies associated with knowledge of an artificial grammar.