Department of Neurosurgery, Washington University School of Medicine in Saint Louis, St. Louis, MO 63110, USA.
National Center for Adaptive Neurotechnologies, St. Louis, MO 63110, USA.
Cereb Cortex. 2023 Jul 5;33(14):8837-8848. doi: 10.1093/cercor/bhad155.
Context modulates sensory neural activations enhancing perceptual and behavioral performance and reducing prediction errors. However, the mechanism of when and where these high-level expectations act on sensory processing is unclear. Here, we isolate the effect of expectation absent of any auditory evoked activity by assessing the response to omitted expected sounds. Electrocorticographic signals were recorded directly from subdural electrode grids placed over the superior temporal gyrus (STG). Subjects listened to a predictable sequence of syllables, with some infrequently omitted. We found high-frequency band activity (HFA, 70-170 Hz) in response to omissions, which overlapped with a posterior subset of auditory-active electrodes in STG. Heard syllables could be distinguishable reliably from STG, but not the identity of the omitted stimulus. Both omission- and target-detection responses were also observed in the prefrontal cortex. We propose that the posterior STG is central for implementing predictions in the auditory environment. HFA omission responses in this region appear to index mismatch-signaling or salience detection processes.
上下文调节感觉神经活动，增强感知和行为表现，减少预测误差。然而，这些高层期望何时何地作用于感觉处理尚不清楚。在这里，我们通过评估对缺失的预期声音的反应来分离没有任何听觉诱发活动的期望的影响。脑电信号直接从置于颞上回 (STG) 上方的硬膜下电极网格中记录。受试者听一个可预测的音节序列，其中一些音节很少缺失。我们发现缺失时高频带活动 (HFA，70-170 Hz)，与 STG 中听觉活跃电极的后部子集重叠。听到的音节可以从 STG 中可靠地区分，但不能区分缺失的刺激的身份。在额叶皮层中也观察到了缺失和目标检测的反应。我们提出，后部 STG 是在听觉环境中实现预测的核心。该区域的 HFA 缺失反应似乎表示失配信号或显着性检测过程。
