The Effect of Binaural Beats on Visuospatial Working Memory and Cortical Connectivity

Binaural beats utilize a phenomenon that occurs within the cortex when two different frequencies are presented separately to each ear. This procedure produces a third phantom binaural beat, whose frequency is equal to the difference of the two presented tones and which can be manipulated for non-invasive brain stimulation. The effects of binaural beats on working memory, the system in control of temporary retention and online organization of thoughts for successful goal directed behavior, have not been well studied. Furthermore, no studies have evaluated the effects of binaural beats on brain connectivity during working memory tasks. In this study, we determined the effects of different acoustic stimulation conditions on participant response accuracy and cortical network topology, as measured by EEG recordings, during a visuospatial working memory task. Three acoustic stimulation control conditions and three binaural beat stimulation conditions were used: None, Pure Tone, Classical Music, 5Hz binaural beats, 10Hz binaural beats, and 15Hz binaural beats. We found that listening to 15Hz binaural beats during a visuospatial working memory task not only increased the response accuracy, but also modified the strengths of the cortical networks during the task. The three auditory control conditions and the 5Hz and 10Hz binaural beats all decreased accuracy. Based on graphical network analyses, the cortical activity during 15Hz binaural beats produced networks characteristic of high information transfer with consistent connection strengths throughout the visuospatial working memory task.

双耳节拍（Binaural beats）利用了一种发生于大脑皮层的现象：当向双耳分别呈现两种不同频率的声学信号时，会产生第三种虚幻的双耳节拍，其频率等于两种输入音调的频率差，可用于无创脑刺激。目前针对双耳节拍对工作记忆（working memory）的影响的研究尚不完善——工作记忆是负责临时信息存储、在线组织思维以实现目标导向行为的认知系统。此外，尚无研究探讨双耳节拍在工作记忆任务中对大脑连接性的影响。本研究中，我们通过脑电（EEG）记录，分析了不同听觉刺激条件下，被试在视觉空间工作记忆任务中的反应准确率与皮层网络拓扑结构的变化。本研究设置了3种听觉刺激对照条件与3种双耳节拍刺激条件：无刺激、纯音、古典音乐、5Hz双耳节拍、10Hz双耳节拍以及15Hz双耳节拍。研究结果显示，在视觉空间工作记忆任务中聆听15Hz双耳节拍，不仅能提升被试的反应准确率，还能调节任务过程中的皮层网络连接强度。而3种听觉对照条件以及5Hz、10Hz双耳节拍均会降低被试的反应准确率。经图网络分析可知，15Hz双耳节拍刺激下的皮层活动所构建的网络具备高信息传递特性，且在整个视觉空间工作记忆任务中保持稳定的连接强度。