Investigating Cognitive and Neural Bases of Working Memory

 描述（由申请人提供）：工作记忆是指在头脑中保持信息，操纵信息并使用信息指导行为的能力。它是一种基本的认知功能，支持计划、解决问题、语言理解和表达等高级能力;它是一个重要的因素，在广泛的实验和“真实的世界”人类表现的测量中，它是个体差异的基础;它的功能障碍是许多精神和神经疾病的特征。目前的建议的首要目标是解决工作记忆是如何工作的问题？通过关注注意力的作用。基于该项目上一个资助周期的研究结果，我们建议通过以下具体目标来研究注意机制对工作记忆表现的贡献和边界条件：具体目标1：检验假设，即在注意和工作记忆任务中，共同的注意相关因素是选择对象或特征的基础。在视觉中，自上而下的注意优先是通过场景中刺激的神经表征之间的有偏竞争机制来实现的。在实验1-4中，我们将使用多变量分析方法，首先描述视觉搜索中有偏见的竞争的时间动态，然后进行头对头比较视觉搜索与视觉工作记忆中的注意优先化的影响。具体目标二：为了检验“注意记忆项目”和“不注意记忆项目”的神经激活状态随策略因素而变化的假设。是否有可能明确地分离将注意力集中在工作记忆中的信息上的神经基础，以及当这些信息暂时不在注意力的焦点之外时保留这些信息的神经基础？为了解决这个问题，我们将系统地改变视觉搜索敏感的两个因素：回溯的有效性;以及搜索的逐个试验可预测性 目标具体目标3：检验顶叶内沟的活动实现以下假设： 工作记忆中注意力的语境控制。虽然在工作记忆任务中，经常在“背侧额顶控制网络”中观察到延迟期活动的增加，但在上一个资助期发表的研究对这种活动与刺激信息的存储本身相对应的概念提出了挑战。追求这一目标的实验将评估IPS作为一个非模式优先级地图的想法，跟踪和管理与当前试验相关的项目的优先级状态。

 DESCRIPTION (provided by applicant): Working memory refers to the ability to hold information in mind, to manipulate it, and to use it to guide behavior. It is an elemental cognitiv function that supports such high-level abilities as planning, problem solving, and language comprehension and production; it is an important factor underlying individual differences across a broad spectrum of experimental and "real world" measures of human performance; and its dysfunction is characteristic of many psychiatric and neurological diseases. The overarching goal of the present proposal is to address the question how does working memory work? by focusing on the role of attention. Building on findings from the previous funding cycle of this project, we propose to investigate the contributions, and boundary conditions, of attentional mechanisms to working memory performance, by pursuing the following Specific Aims: Specific Aim 1: To test the hypothesis that common attention-related factors underlie the selection of an object, or a feature, in both attention and working memory tasks. In vision, top-down attentional priority is implemented via the mechanism of biased competition among neural representations of stimuli in the scene. In Experiments 1-4, we will use multivariate analysis methods to first characterize the temporal dynamics of biased competition in visual search, then perform head-to-head comparisons of the effects of attentional prioritization in visual search vs. in visual working memory. Specific Aim 2: To test the hypothesis that the state of neural activation of `attended memory items' and of `unattended memory items' varies with strategic factors. Is it possible to definitively dissociate the neural bases of focusing attention on information held in working memory vs. the retention of this information when it is momentarily outside of the focus of attention? To address this question we will systematically vary two factors to which visual search is sensitive: the validity of retrocues; and the trial-to-trial predictability of the search target. Specific Aim 3: To test the hypothesis that activity in the intraparietal sulcus implements the context- appropriate control of attention in working memory. Although elevated delay-period activity is frequently observed in the "dorsal frontoparietal control network" during working memory tasks, research published during the previous funding period has challenged the notion that this activity corresponds to the storage, per se, of stimulus information. The experiments pursing this Aim will assess the idea that IPS functions as an amodal priority map that tracks and manages the priority status of items that are relevant for the current trial.