Investigating Working Memory Encoding using Frequency-Tagging of Evoked Response

描述(由申请者提供)：工作记忆(WM)是允许我们保持和操作从电话号码到我们周围物品的在线心理表征的“心理工作空间”。鉴于WM对健康认知的关键重要性，WM损伤会导致生活质量显著下降也就不足为奇了。因此，了解健康的WM功能背后的行为和神经机制对于有朝一日开发治疗和干预措施以延缓WM表现的下降至关重要。尽管它对执行认知任务很重要，但WM的一个令人惊讶的特点是它的容量严重受限于~4个项目。围绕着WM的谜团之一是这种容量限制是如何以及为什么出现的。容量限制的一个潜在来源可能是来自环境的物品在任何给定时间从我们周围的许多可能的物品被编码到WM中的方式。以前的工作依赖于行为和生理测量来研究影响WM编码的因素，例如编码深度、刺激数量或刺激集大小的操纵。然而，所有这些以前的方法都使用了与执行工作记忆任务相关的聚合加工的间接测量，并且没有一个直接关注与特定个体刺激的编码相关的过程。在这里，我们建议应用一种强大的事件相关电位(ERP)技术：频率标记，以直接测量编码时单个项目的加工。这一技术已被广泛应用于视觉感知的研究中，本文建议将其应用于WM编码的全面研究。这种方法需要呈现刺激，每个刺激以独特的闪烁速率闪烁和关闭。有趣的是，这种周期性刺激导致相应的神经振荡，可以记录在脑电(EEG)中，并通过观察刺激闪烁的频率在频域中进行分析。这些“频率标签”的幅度可以与行为结果相关联，即是否成功地从WM中提取刺激，以获得特定于个体刺激的WM编码的神经元关联。这份R15/AREA拨款方案结合了两名研究人员的理论和技术专长，以及多年研究视觉感知和记忆的经验。PIS将与本科生和研究生密切合作，促进我们对WM编码过程的理解。通过拟议的实验，学生将接受多个领域的培训(对建立坚实的基础，在此基础上建立未来的心理学和神经科学的研究生涯至关重要)。这一创新提议将大大促进内华达大学里诺分校的研究和教育培训目标 与公共健康相关：工作记忆(WM)是认知的一个基本方面，容量非常有限。这项建议的基本目标是加深我们对构成健康的WM功能的行为和神经机制的理解。从长远来看，这项研究可能有助于开发有效的干预和治疗方法，旨在预防或减轻WM损害。这份R15/AREA拨款提案使用一种称为频率标记的强大的ERP方法来研究WM编码过程。我们建议两个实验室(Caplovitz Vision Lab和BerryHill Memory and Brain Lab)合作，为学生提供多种实验技术方面的培训，以回答WM领域长期存在的问题。

DESCRIPTION (provided by applicant): Working memory (WM) serves as the 'mental workspace' permitting us to maintain and manipulate on-line mental representations of everything from a phone number to the objects around us. Given its critical importance for healthy cognition, it is not surprising that WM impairments can lead to a significant decrease in the quality of life. As such, understanding the behavioral and neuronal mechanisms that underlie healthy WM function is critical to one day developing treatments and interventions to stave off declines in WM performance. In spite of its importance for performing cognitive tasks, a surprising feature of WM is that it is severely capacity limited to ~4 items. One of the mysterie surrounding WM is how and why this capacity limitation arises. One potential source of capacity limitation may arise from how items from the environment are encoded into WM from the numerous possible items around us at any given time. Previous work has relied on behavioral and physiological measures to study factors influencing WM encoding, e.g. manipulations of encoding depth, stimulus number, or stimulus set size. However, all of these previous approaches used indirect measurements of the aggregate processing associated with performing the WM task, and none have focused directly on the processes associated with the encoding of a specific individual stimulus. Here, we propose to apply a powerful event related potential (ERP) technique: Frequency-Tagging, to directly measure the processing of individual items at encoding. This technique has been widely used in the study of visual perception, and here we propose to apply it to perform a comprehensive investigation of WM encoding. The approach entails the presentation of stimuli each flickering on and off at unique flicker rate. Intriguingly, this periodic stimulation leads to corresponding neural oscillations that can be recorded in the electroencephalogram (EEG) and analyzed in the frequency domain by looking at the frequencies at which a stimulus was flickered. The amplitudes of these 'frequency-tags' can be correlated with the behavioral outcomes of whether or not the stimulus is successfully retrieved from WM to obtain a neuronal correlate of WM encoding that is specific to an individual-stimulus. This R15/AREA grant proposal combines the theoretical and technical expertise of two researchers with years of experience studying visual perception and memory. The PIs will work closely with undergraduate and graduate students to advance our understanding of the WM encoding process. Through the proposed experiments, students will receive training in a number of areas (critical to establishing a solid foundation upon which to build future research careers in psychology and neuroscience. This innovative proposal will significantly contribute to the research and educational training goals of the University of Nevada, Reno PUBLIC HEALTH RELEVANCE: Working memory (WM) is a fundamental aspect of cognition that is highly limited in capacity. The fundamental goal of this proposal is to further our understanding of the behavioral and neural mechanisms that underlie healthy WM function. In the long-term, this research may contribute to the development of effective interventions and treatments designed to prevent or alleviate WM impairments. This R15/AREA grant proposal investigates the WM encoding process using a powerful ERP approach called frequency-tagging. We propose the collaboration between two laboratories (Caplovitz Vision Lab and the Berryhill Memory and Brain Lab) to provide student training in multiple experimental techniques to answer longstanding questions in the WM field.