Department of Mathematics and Statistics, University of New Mexico Albuquerque, NM, USA ; Department of Biology, Initiative for Maximizing Student Development, University of New Mexico Albuquerque, NM, USA ; The Mind Research Network, University of New Mexico Albuquerque, NM, USA.
Front Hum Neurosci. 2013 Jul 15;7:370. doi: 10.3389/fnhum.2013.00370. eCollection 2013.
Information must integrate from multiple brain areas in healthy cognition and perception. The present study examined the extent to which cortical responses within one sensory modality are modulated by a complex task conducted within another sensory modality. Electroencephalographic (EEG) responses were measured to a 40 Hz auditory stimulus while individuals attended to modulations in the amplitude of the 40 Hz stimulus, and as a function of the difficulty of the popular computer game Tetris. The steady-state response to the 40 Hz stimulus was isolated by Fourier analysis of the EEG. The response at the stimulus frequency was normalized by the response within the surrounding frequencies, generating the signal-to-noise ratio (SNR). Seven out of eight individuals demonstrate a monotonic increase in the log SNR of the 40 Hz responses going from the difficult visuospatial task to the easy visuospatial task to attending to the auditory stimuli. This pattern is represented statistically by a One-Way ANOVA, indicating significant differences in log SNR across the three tasks. The sensitivity of 40 Hz auditory responses to the visuospatial load was further demonstrated by a significant correlation between log SNR and the difficulty (i.e., speed) of the Tetris task. Thus, the results demonstrate that 40 Hz auditory cortical responses are influenced by an individual's goal-directed attention to the stimulus, and by the degree of difficulty of a complex visuospatial task.
信息必须在健康认知和感知中从多个脑区整合。本研究考察了在一种感觉模态内的皮质反应在多大程度上受到另一种感觉模态内的复杂任务的调节。当个体关注 40Hz 刺激幅度的调制以及流行的电脑游戏 Tetris 的难度时，测量了对 40Hz 听觉刺激的脑电 (EEG) 反应。通过对 EEG 的傅里叶分析来分离 40Hz 刺激的稳态反应。通过将刺激频率内的响应归一化为周围频率内的响应，生成信号与噪声比 (SNR)。8 个人中有 7 个人从困难的空间视觉任务到简单的空间视觉任务再到关注听觉刺激，其 40Hz 反应的对数 SNR 呈单调增加。这种模式由单向方差分析表示，表明三个任务的对数 SNR 存在显著差异。40Hz 听觉反应对空间视觉负荷的敏感性进一步通过对数 SNR 与 Tetris 任务的难度（即速度）之间的显著相关性得到证明。因此，结果表明，40Hz 听觉皮质反应受到个体对刺激的目标导向注意以及复杂空间视觉任务的难度的影响。
