Department of Biomedical Engineering, Faculty of Engineering, Mahidol University, Salaya, Nakhorn Pathom 73170, Thailand.
Int J Psychophysiol. 2017 Oct;120:96-107. doi: 10.1016/j.ijpsycho.2017.07.010. Epub 2017 Jul 21.
Gamma oscillation plays a role in binding process or sensory integration, a process by which several brain areas beside primary cortex are activated for higher perception of the received stimulus. Beta oscillation is also involved in interpreting received stimulus and occurs following gamma oscillation, and this process is known as gamma-to-beta transition, a process for neglecting unnecessary stimuli in surrounding environment. Gamma oscillation also associates with cognitive functions, memory and emotion. Therefore, modulation of the brain activity can lead to manipulation of cognitive functions. The stimulus used in this study was 40-Hz binaural beat because binaural beat induces frequency following response. This study aimed to investigate the neural oscillation responding to the 40-Hz binaural beat and to evaluate working memory function and emotional states after listening to that stimulus. Two experiments were developed based on the study aims. In the first experiment, electroencephalograms were recorded while participants listened to the stimulus for 30min. The results suggested that frontal, temporal, and central regions were activated within 15min. In the second experiment, word list recall task was conducted before and after listening to the stimulus for 20min. The results showed that, after listening, the recalled words were increase in the working memory portion of the list. Brunel Mood Scale, a questionnaire to evaluate emotional states, revealed changes in emotional states after listening to the stimulus. The emotional results suggested that these changes were consistent with the induced neural oscillations.
伽马振荡在绑定过程或感觉整合中起作用，这是一个除了初级皮层之外的几个大脑区域被激活以实现对所接收刺激的更高感知的过程。β振荡也参与接收刺激的解释，并在伽马振荡之后发生，这个过程被称为伽马到β过渡，是一个忽略周围环境中不必要刺激的过程。伽马振荡还与认知功能、记忆和情绪有关。因此，大脑活动的调节可以导致认知功能的操纵。本研究使用的刺激是 40Hz 双耳节拍，因为双耳节拍诱导频率跟随反应。本研究旨在研究对 40Hz 双耳节拍的神经振荡反应，并评估在听到该刺激后的工作记忆功能和情绪状态。基于研究目的，进行了两项实验。在第一项实验中，当参与者听刺激 30 分钟时记录脑电图。结果表明，在 15 分钟内激活了额、颞和中央区域。在第二项实验中，在听刺激前后进行了 20 分钟的单词列表回忆任务。结果表明，在听刺激后，工作记忆部分的回忆单词增加了。用于评估情绪状态的 Brunel 情绪量表显示，在听刺激后情绪状态发生了变化。情绪结果表明，这些变化与诱导的神经振荡一致。
