Infusion of protein synthesis inhibitors in the entorhinal cortex blocks consolidation but not reconsolidation of object recognition memory

Memory consolidation and reconsolidation require the induction of protein synthesis in some areas of the brain. Here, we show that infusion of the protein synthesis inhibitors anisomycin, emetine and cycloheximide in the entorhinal cortex immediately but not 180 min or 360 min after training in an object recognition learning task hinders long-term memory retention without affecting short-term memory or behavioral performance. Inhibition of protein synthesis in the entorhinal cortex after memory reactivation involving either a combination of familiar and novel objects or two familiar objects does not affect retention. Our data suggest that protein synthesis in the entorhinal cortex is necessary early after training for consolidation of object recognition memory. However, inhibition of protein synthesis in this cortical region after memory retrieval does not seem to affect the stability of the recognition trace.     

传递性推理的ERP研究

以抽象的内容作为实验材料,测定15名大学生在完成三种不同类型的传递性推理任务和基线任务(记忆判断任务)时的事件相关电位(ERP),探讨传递性推理过程的脑内时程动态变化。研究发现,三种推理任务所诱发的波形基本一致,而推理任务与基线任务之间的ERP波形存在明显的差异。这说明对于传递性推理,被试可能是根据视觉的空间表征对信息进行加工的,结果进一步支持了心理模型理论。     

Does medial prefrontal cortex activity during self‐knowledge reference reflect the uniqueness of self‐knowledge?1

Abstract: For this study, functional magnetic resonance imaging was used to examine whether medial prefrontal cortex (MPFC) activity during self‐knowledge reference reflects the uniqueness of self‐knowledge. Experiment 1 investigated neural activity during self‐knowledge reference (“Does the word describe you?”) and self‐monitoring (“Does the word make you feel pleasant?”). The results showed that self‐knowledge reference and self‐monitoring activate common neural substrates within the MPFC. Experiment 2 compared neural activity produced by self‐knowledge reference, other‐knowledge (acquaintance‐knowledge) reference (“Does this word describe the person?”), and evaluation (“Is this word socially desirable?”). Results showed no increase in MPFC activity during self‐knowledge reference relative to other‐knowledge reference. Furthermore, self‐knowledge reference and other‐knowledge reference share common neural substrates within the MPFC. The results described indicate that it is unlikely that MPFC activity during self‐knowledge reference reflects the uniqueness of self‐knowledge. The feature, as reflected in MPFC activity, is discussed.     

Hierarchically organized behavior and its neural foundations: a reinforcement learning perspective

Research on human and animal behavior has long emphasized its hierarchical structure—the divisibility of ongoing behavior into discrete tasks, which are comprised of subtask sequences, which in turn are built of simple actions. The hierarchical structure of behavior has also been of enduring interest within neuroscience, where it has been widely considered to reflect prefrontal cortical functions. In this paper, we reexamine behavioral hierarchy and its neural substrates from the point of view of recent developments in computational reinforcement learning. Specifically, we consider a set of approaches known collectively as hierarchical reinforcement learning, which extend the reinforcement learning paradigm by allowing the learning agent to aggregate actions into reusable subroutines or skills. A close look at the components of hierarchical reinforcement learning suggests how they might map onto neural structures, in particular regions within the dorsolateral and orbital prefrontal cortex. It also suggests specific ways in which hierarchical reinforcement learning might provide a complement to existing psychological models of hierarchically structured behavior. A particularly important question that hierarchical reinforcement learning brings to the fore is that of how learning identifies new action routines that are likely to provide useful building blocks in solving a wide range of future problems. Here and at many other points, hierarchical reinforcement learning offers an appealing framework for investigating the computational and neural underpinnings of hierarchically structured behavior.     

Object-location memory: A lesion-behavior mapping study in stroke patients

Object-location memory is an important form of spatial memory, comprising different subcomponents that each process specific types of information within memory, i.e. remembering objects, remembering positions and binding these features in memory. In the current study we investigated the neural correlates of binding categorical (relative) or coordinate (exact) position information with objects in memory. Therefore, an object-location memory battery was used, including different task conditions assessing object-location memory, i.e. memory for position information per se, and binding object information with coordinate and categorical position information. Sixty-one stroke patients with focal brain lesions were examined and compared with 77 healthy matched controls. The lesion subtraction method was used to define the area of overlap. Results indicate an important role of the left posterior parietal cortex in the binding of both categorical and coordinate positions with object information. Additionally, the hippocampus seems important for categorical object-location memory. This suggests that categorical and coordinate object-location memory depend on similar cognitive and neural systems.     

Enhanced divergent thinking and creativity in musicians: a behavioral and near-infrared spectroscopy study

Empirical studies of creativity have focused on the importance of divergent thinking, which supports generating novel solutions to loosely defined problems. The present study examined creativity and frontal cortical activity in an externally-validated group of creative individuals (trained musicians) and demographically matched control participants, using behavioral tasks and near-infrared spectroscopy (NIRS). Experiment 1 examined convergent and divergent thinking with respect to intelligence and personality. Experiment 2 investigated frontal oxygenated and deoxygenated hemoglobin concentration changes during divergent thinking with NIRS. Results of Experiment 1 indicated enhanced creativity in musicians who also showed increased verbal ability and schizotypal personality but their enhanced divergent thinking remained robust after co-varying out these two factors. In Experiment 2, NIRS showed greater bilateral frontal activity in musicians during divergent thinking compared with nonmusicians. Overall, these results suggest that creative individuals are characterized by enhanced divergent thinking, which is supported by increased frontal cortical activity.     

前运动皮质与数字加工:脑功能成像研究的元分析研究

许多应用PET与fMRI技术的脑功能成像研究发现,数字加工任务会显著引起前运动皮质的激活。习惯上认为,这一结果可能与任务执行过程中的动作反应,如手指按键、默读或眼动等有关。近年来的研究则表明,这一区域不仅具有动作功能,同时也具有其它非动作的认知功能。在本研究中,对17篇关于数字加工的脑功能成像研究进行了元分析,以考察前运动皮质在数字加工中的作用。研究结果发现,运动前区的背外侧(PMd)与腹外侧(PMv)在大多数数字加工任务中有显著激活,而运动辅助区(SMA)的激活则相对较少。数字比较、加法与减法任务在PMd区域有更多的激活,而乘法任务则在PMv区域有更多激活。数字自身特征对PMd、PMv与SMA喙部区域的激活有显著的调节作用。这一结果表明,前运动皮质在数字加工过程中可能扮演着比动作反应更为重要的角色。     

执行功能与攻击行为关系的研究

攻击行为产生的原因十分复杂,受当今认知神经科学的影响,心理学研究人员从执行功能的角度来探讨攻击行为。现有的研究主要从心理学、流行病学、行为神经学、神经心理学和神经成像角度,考察和分析二者内在的关联,结果表明在暴力犯罪、反社会人格、杀人犯、精神病患者、少年犯、注意缺陷-多动障碍等群体,执行功能与攻击行为间存在很强的负向关联。将来的研究需要拓宽研究被试群体,深入考察内在的脑机制,制定恰当的攻击行为干预方法。     

Mirror Neurons and the Evolution of Embodied Language

ABSTRACT— Mirror neurons are a class of neurons first discovered in the monkey premotor cortex that activate both when the monkey executes an action and when it observes the same action made by another individual. These neurons enable individuals to understand actions performed by others. Two subcategories of mirror neurons in monkeys activate when they listen to action sounds and when they observe communicative gestures made by others, respectively. The properties of mirror neurons could constitute a substrate from which more sophisticated forms of communication evolved; this would make sense, given the anatomical and functional homology between part of the monkey premotor cortex and Broca's area (the "speech" area of the brain) in humans. We hypothesize that several components of human language, including some aspects of phonology and syntax, could be embedded in the organizational properties of the motor system and that a deeper knowledge of this system could shed light on how language evolved.