Neuroscience Department, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
Centro Avanzado de Ingeniería Eléctrica y Electrónica, AC3E, Universidad Técnica Federico Santa María, Valparaiso, Chile.
J Neurophysiol. 2021 Jun 1;125(6):2309-2321. doi: 10.1152/jn.00032.2020. Epub 2021 May 12.
Top-down modulation of sensory responses to distracting stimuli by selective attention has been proposed as an important mechanism by which our brain can maintain relevant information during working memory tasks. Previous works in visual working memory (VWM) have reported modulation of neural responses to distracting sounds at different levels of the central auditory pathways. Whether these modulations occur also at the level of the auditory receptor is unknown. Here, we hypothesize that cochlear responses to irrelevant auditory stimuli can be modulated by the medial olivocochlear system during VWM. Twenty-one subjects (13 males, mean age 25.3 yr) with normal hearing performed a visual change detection task with different VWM load conditions (high load = 4 visual objects; low load = 2 visual objects). Auditory stimuli were presented as distractors and allowed the measurement of distortion product otoacoustic emissions (DPOAEs) and scalp auditory evoked potentials. In addition, the medial olivocochlear reflex strength was evaluated by adding contralateral acoustic stimulation. We found larger contralateral acoustic suppression of DPOAEs during the visual working memory period ( = 21) compared with control experiments ( = 10), in which individuals were passively exposed to the same experimental conditions. These results show that during the visual working memory period there is a modulation of the medial olivocochlear reflex strength, suggesting a possible common mechanism for top-down filtering of auditory responses during cognitive processes. The auditory efferent system has been proposed to function as a biological filter of cochlear responses during selective attention. Here, we recorded electroencephalographic activity and otoacoustic emissions in response to auditory distractors during a visual working memory task in humans. We found that the olivocochlear efferent activity is modulated during the visual working memory period suggesting a common mechanism for suppressing cochlear responses during selective attention and working memory.
选择性注意对分心刺激的感觉反应的自上而下的调制被认为是大脑在工作记忆任务中维持相关信息的重要机制。先前在视觉工作记忆（VWM）中的研究报告了在中枢听觉途径的不同水平上对分心声音的神经反应的调制。这些调制是否也发生在听觉受体水平尚不清楚。在这里，我们假设在 VWM 期间，内侧橄榄耳蜗系统可以调节对无关听觉刺激的耳蜗反应。21 名听力正常的受试者（男性 13 名，平均年龄 25.3 岁）在不同的 VWM 负荷条件下（高负荷=4 个视觉对象；低负荷=2 个视觉对象）进行了视觉变化检测任务。听觉刺激作为分心物呈现，并允许测量畸变产物耳声发射（DPOAEs）和头皮听觉诱发电位。此外，通过添加对侧声刺激来评估内侧橄榄耳蜗反射强度。我们发现，与对照实验（ = 10）相比，在视觉工作记忆期间（ = 21），DPOAEs 的对侧声抑制更大，在对照实验中，个体被动暴露于相同的实验条件下。这些结果表明，在视觉工作记忆期间，内侧橄榄耳蜗反射强度发生调制，这表明在认知过程中对听觉反应进行自上而下滤波的可能存在共同机制。听觉传出系统被提议在选择性注意期间作为耳蜗反应的生物滤波器发挥作用。在这里，我们在人类视觉工作记忆任务期间记录了听觉分心物的脑电图活动和耳声发射。我们发现，在视觉工作记忆期间，橄榄耳蜗传出活动发生调制，这表明在选择性注意和工作记忆期间抑制耳蜗反应存在共同机制。
