Decoding of hemodynamic signals during the processing of spectral and spatial stimulus features in auditory working memory

工作记忆是许多认知功能的核心组成部分，因此与人类的认知和行动密切相关。以前的工作主要集中在保持简单的视觉刺激活跃的短时间内，并对他们进行心理操作的能力。当前的研究主题涉及工作记忆存储的单位和哪些大脑区域可以被认为是存储区域的问题。我们实验室以前的脑磁图研究调查了听觉工作记忆，这是不太好理解比视觉工作记忆。我们的主要发现之一是，空间与非空间声音特征的维持是独立的皮层区域。此外，我们还评估了记忆内容的优先顺序及其对视觉工作记忆中神经元表征的影响。本研究旨在将现有的研究成果从视觉通道转移到听觉工作记忆，并进一步阐明工作记忆的基本、独立于通道的机制。我们将使用解码的功能磁共振成像数据，以确定听觉工作记忆的存储区域。一系列的三个研究应确定哪些区域满足以下标准的存储区域：编码的信息相关的记忆刺激，激活模式和精确的记忆表征之间的相关性在单次试验的基础上，对分心的表征在维护阶段的阻力，和灵活的优先级的特定的记忆内容。我们将使用具有可变空间和频谱特性的非语言声音。因此，我们可以测试哪些区域优先编码单个刺激特征或特征束。我们希望，这个项目将提高我们的知识听觉工作记忆，并提供新的基本见解的作用，感觉和层次较高的地区，为维护简单的和组合的刺激功能。

Working memory forms a central component of many cognitive functions and is thus fundamentally relevant to human cognition and action. Previous work has focused mainly on the ability to keep simple visual stimuli active for short time periods and to perform mental operations on them. Current research topics concern the unit of working memory storage and the question which brain regions can be considered storage regions. Previous magnetoencephalography studies from our laboratory have investigated auditory working memory, which is less well understood than visual working memory. Among our main findings were separate cortical regions for the maintenance of spatial versus nonspatial sound features. Moreover, we have assessed the prioritization of memory contents and its impact on neuronal representations in visual working memory. The present project aims at transferring current findings from the visual modality to auditory working memory and at further elucidating basic, modality-independent mechanisms of working memory. We will use decoding of functional magnetic resonance imaging data to identify auditory working memory storage regions. A series of three studies shall determine which regions fulfill the following criteria for storage regions: coding of information related to the memorized stimulus, correlation between the activation pattern and the precision of memory representations on single-trial basis, resistance of representations against distraction during the maintenance phase, and flexible prioritization of specific memory contents. We will use nonverbal sounds with variable spatial and spectral properties. Thus we can test which regions code preferentially either individual stimulus features or feature bundles. We expect that this project will enhance our knowledge about auditory working memory and provide new fundamental insights into the roles of sensory and hierarchically higher regions for the maintenance of simple and combined stimulus features.