Department of Psychology, University of Oslo, Forskningsveien 3A, 0373 Oslo, Norway.
RITMO Centre for Interdisciplinary Studies in Rhythm, Time and Motion, University of Oslo, Forskningsveien 3A, 0373 Oslo, Norway.
Cereb Cortex. 2023 Feb 20;33(5):1876-1894. doi: 10.1093/cercor/bhac179.
It is largely unknown how attention adapts to the timing of acoustic stimuli. To address this, we investigated how hemispheric lateralization of alpha (7-13 Hz) and beta (14-24 Hz) oscillations, reflecting voluntary allocation of auditory spatial attention, is influenced by tempo and predictability of sounds. We recorded electroencephalography while healthy adults listened to rhythmic sound streams with different tempos that were presented dichotically to separate ears, thus permitting manipulation of spatial-temporal attention. Participants responded to stimulus-onset-asynchrony (SOA) deviants (-90 ms) for given tones in the attended rhythm. Rhythm predictability was controlled via the probability of SOA deviants per block. First, the results revealed hemispheric lateralization of beta-power according to attention direction, reflected as ipsilateral enhancement and contralateral suppression, which was amplified in high- relative to low-predictability conditions. Second, fluctuations in the time-resolved beta-lateralization aligned more strongly with the attended than the unattended tempo. Finally, a trend-level association was found between the degree of beta-lateralization and improved ability to distinguish between SOA-deviants in the attended versus unattended ear. Differently from previous studies, we presented continuous rhythms in which task-relevant and irrelevant stimuli had different tempo, thereby demonstrating that temporal alignment of beta-lateralization with attended sounds reflects top-down attention to sound timing.
目前人们对注意力如何适应声音刺激的时间节奏还知之甚少。为了解决这个问题，我们研究了反映听觉空间注意力自主分配的α（7-13Hz）和β（14-24Hz）振荡的大脑半球侧化如何受到声音节奏和可预测性的影响。我们在健康成年人听具有不同节奏的节奏性声音流时记录了脑电图，这些声音通过双耳分听呈现，从而可以操纵空间-时间注意力。参与者对注意节律中给定音调的刺激出现时间差异（SOA）偏差（-90ms）做出反应。通过每个块中 SOA 偏差的概率来控制节奏的可预测性。首先，结果显示β功率根据注意方向表现出半球侧化，表现为同侧增强和对侧抑制，在高可预测性条件下比低可预测性条件下放大。其次，与未注意的节奏相比，时间分辨β侧化的波动与注意的节奏更紧密地对齐。最后，β侧化程度与区分注意耳和未注意耳中 SOA 偏差的能力之间存在趋势关联。与之前的研究不同，我们呈现了连续的节奏，其中与任务相关和不相关的刺激具有不同的节奏，从而证明β侧化与注意声音的时间对准反映了自上而下的对声音时间的注意。
