|其他题名||Role of neural oscillations in maintenance of human visual working memory representations|
Human visual system receives many cluttered stimuli simultaneously, but only a few of visual representations can be held in the mind to guide subsequent goal-oriented behaviors, which indicates the limited capacity of visual working memory. Meanwhile, the neural representations of visual stimuli can be noisy and hence the memory precision is varying. This review systematically illustrates the roles of neural oscillations in maintaining visual working memory and neural mechanisms underlying the capacity and precision. In the end, several potential directions of this field for future studies are discussed. A large amount of researches demonstrates that during the maintenance of visual working memory representations, the theta band oscillations can facilitate the neural information communications between brain regions throughout a relative long distance, in order to achieve the top-down cognitive control; the alpha band oscillations, which was initially considered as an electrophysiological correlate of cortical idling, are now generally treated to reflect functional inhibition or non-engagement of a given brain regions, in order to gate neural information to the task-relevant regions; as for gamma band, the high frequency oscillation property make it suitable for the integration of multiple object features in the local neural network and hold the relevant representations. Therefore, theta and gamma band engage in the maintenance of working memory representations directly, while alpha oscillations serve in an indirect way of functional inhibition. In addition, the cross frequency coupling and neural synchronization enable the collaboration of different brain regions in the working memory network. The contralateral delay activity（CDA） is widely acknowledged to be an online electrophysiological marker of working memory capacity. In addition, the alpha oscillations in irrelevant regions also have a strong correlation with individual capacity. Early studies that aimed to explore memory capacity limit introduce the slot model of working memory, which regards working memory as few fixed discrete slots and cannot be divided between items. However, more and more experiments that are designed to study memory precision come to conceptualize working memory as a limited resource that can be shared between different representations, and put forward the resource model of working memory. One of the major differences of these two models is the change of memory precision with memory load increasing, so the study of memory precision is conductive to figure out the working memory model. Although several behavioral studies have demonstrated that both capacity and precision are two distinct aspects of working memory, some electrophysiological researches propose that CDA and alpha band oscillations can also represent the memory precision. Therefore, more studies would be needed to explore the neural substrates of memory precision. In addition to the passive maintenance of working memory representations, the active manipulation of memories, such as updating, is a potential direction of working memory studies, since it can give us a whole picture of how the memory resources are dynamically distributed among objects. Moreover, neural decoding of objects is also an important research perspective, which can directly manifest the storage of memory representations.
|关键词||视觉工作记忆 神经振荡 记忆维持 记忆容量 记忆精确度|
|项目资助者||国家自然科学基金（81371631 ; 81422024） ; 青年千人计划（Y4HX072006） ; 北京市科技新星计划（Z141110001814068）|
|潘亚丽,王亮. 神经振荡在人类视觉工作记忆表征维持中的作用[J]. 科学通报,2016,61(15):1650-1660.|
|MLA||潘亚丽,et al."神经振荡在人类视觉工作记忆表征维持中的作用".科学通报 61.15(2016):1650-1660.|