Computational Neuroscience and Cognitive Robotics Centre, University of Birmingham, Birmingham, UK.
Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands.
Nat Hum Behav. 2022 May;6(5):732-742. doi: 10.1038/s41562-022-01294-x. Epub 2022 Feb 24.
An intriguing notion in cognitive neuroscience posits that alpha oscillations mould how the brain parses the constant influx of sensory signals into discrete perceptual events. Yet, the evidence is controversial and the underlying neural mechanism unclear. Further, it is unknown whether alpha oscillations influence observers' perceptual sensitivity (that is, temporal resolution) or their top-down biases to bind signals within and across the senses. Combining electroencephalography, psychophysics and signal detection theory, this multi-day study rigorously assessed the impact of alpha frequency on temporal binding of signals within and across the senses. In a series of two-flash discrimination experiments, 20 human observers were presented with one or two flashes together with none, one or two sounds. Our results provide robust evidence that pre-stimulus alpha frequency as a dynamic neural state and an individual's trait index do not influence observers' perceptual sensitivity or bias for two-flash discrimination in any of the three sensory contexts. These results challenge the notion that alpha oscillations have a profound impact on how observers parse sensory inputs into discrete perceptual events.
认知神经科学中一个有趣的观点认为，α 振荡模式塑造了大脑如何将持续不断的感官信号输入解析为离散的感知事件。然而，这一证据存在争议，其潜在的神经机制尚不清楚。此外，目前尚不清楚 α 振荡是否会影响观察者的感知敏感性（即时间分辨率），或者他们在感觉内和跨感觉绑定信号的自上而下的偏见。本研究结合脑电图、心理物理学和信号检测理论，严格评估了 α 频率对感觉内和跨感觉信号的时间绑定的影响。在一系列的双闪光辨别实验中，20 名人类观察者被呈现一个或两个闪光，以及没有、一个或两个声音。我们的结果提供了有力的证据，表明刺激前的 α 频率作为一种动态的神经状态和个体的特质指数，不会影响观察者在任何三种感觉环境下的双闪光辨别感知敏感性或偏见。这些结果挑战了 α 振荡对观察者将感官输入解析为离散感知事件的深刻影响的观点。
