Tanaka Keita, Ross Bernhard, Kuriki Shinya, Harashima Tsuneo, Obuchi Chie, Okamoto Hidehiko
Department of Science and Engineering, Tokyo Denki University, Saitama, Japan.
Baycrest Centre, Rotman Research Institute, Toronto, ON, Canada.
Front Psychol. 2021 Jul 8;12:696263. doi: 10.3389/fpsyg.2021.696263. eCollection 2021.
Right-ear advantage refers to the observation that when two different speech stimuli are simultaneously presented to both ears, listeners report stimuli more correctly from the right ear than the left. It is assumed to result from prominent projection along the auditory pathways to the contralateral hemisphere and the dominance of the left auditory cortex for the perception of speech elements. Our study aimed to investigate the role of attention in the right-ear advantage. We recorded magnetoencephalography data while participants listened to pairs of Japanese two-syllable words (namely, "/ta/ /ko/" or "/i/ /ka/"). The amplitudes of the stimuli were modulated at 35 Hz in one ear and 45 Hz in the other. Such frequency-tagging allowed the selective quantification of left and right auditory cortex responses to left and right ear stimuli. Behavioral tests confirmed the right-ear advantage, with higher accuracy for stimuli presented to the right ear than to the left. The amplitude of the auditory steady-state response was larger when attending to the stimuli compared to passive listening. We detected a correlation between the attention-related increase in the amplitude of the auditory steady-state response and the laterality index of behavioral accuracy. The right-ear advantage in the free-response dichotic listening was also found in neural activities in the left auditory cortex, suggesting that it was related to the allocation of attention to both ears.
当两个不同的语音刺激同时分别呈现给双耳时，听众对来自右耳的刺激的报告比对左耳的更准确。一般认为，这是由于听觉通路向对侧半球的显著投射以及左听觉皮层在语音元素感知方面的主导作用所致。我们的研究旨在探究注意力在右耳优势中的作用。在参与者听成对的日语双音节词（即“/ta/ /ko/”或“/i/ /ka/”）时，我们记录了脑磁图数据。刺激的幅度在一只耳朵中以35赫兹调制，在另一只耳朵中以45赫兹调制。这种频率标记使得能够选择性地量化左、右听觉皮层对左耳和右耳刺激的反应。行为测试证实了右耳优势，即呈现给右耳的刺激比呈现给左耳的刺激具有更高的准确性。与被动聆听相比，当专注于刺激时，听觉稳态反应的幅度更大。我们检测到听觉稳态反应幅度与行为准确性的偏侧性指数之间存在相关性。在自由反应双耳分听中，左听觉皮层的神经活动也发现了右耳优势，这表明它与对双耳注意力的分配有关。
