Department of Psychological Science, Health and Territory, "G. d'Annunzio" University of Chieti and Pescara, Chieti, Italy.
Department of Neuroscience, Imaging and Clinical Sciences, "G. d'Annunzio" University of Chieti and Pescara, Chieti, Italy.
Brain Struct Funct. 2018 Mar;223(2):965-979. doi: 10.1007/s00429-017-1538-4. Epub 2017 Oct 25.
The focus of the present study is on the relationships between illusory and non-illusory auditory perception analyzed at a biological level. To this aim, we investigate neural mechanisms underlying the Deutsch's illusion, a condition in which both sound identity ("what") and origin ("where") are deceptively perceived. We recorded magnetoencephalogram from healthy subjects in three conditions: (a) listening to the acoustic sequence eliciting the illusion (ILL), (b) listening to a monaural acoustic sequence mimicking the illusory percept (MON), and (c) listening to an acoustic sequence similar to (a) but not eliciting the illusion (NIL). Results show that the areas involved in the illusion were the Heschl's gyrus, the insular cortex, the inferior frontal gyrus, and the medial-frontal gyrus bilaterally, together with the left inferior-parietal lobe. These areas belong to the two main auditory streams known as the what and where pathways. The neural responses there observed indicate that the sound sequence eliciting the illusion is associated to larger activity at early and middle latencies and to a dynamic lateralization pattern net in favor of the left hemisphere. The present findings extend to illusory perception the well-known what-where auditory processing mechanism, especially as regards tardy latency activity.
本研究的重点是在生物层面分析虚幻和非虚幻听觉感知之间的关系。为此，我们研究了 Deutsch 错觉背后的神经机制，在这种错觉中，声音的身份（“什么”）和来源（“哪里”）都被欺骗性地感知到。我们在三种条件下从健康受试者记录了脑磁图：（a）听诱发错觉的声序列（ILL），（b）听模拟虚幻知觉的单耳声序列（MON），以及（c）听类似于（a）但不诱发错觉的声序列（NIL）。结果表明，参与错觉的区域是双侧的 Heschl 回、岛叶皮质、额下回和额中回，以及左顶下叶。这些区域属于被称为“什么”和“哪里”通路的两个主要听觉流。在那里观察到的神经反应表明，诱发错觉的声序列与早期和中期潜伏期的更大活动以及有利于左半球的动态侧化模式有关。目前的发现将众所周知的“什么-哪里”听觉处理机制扩展到了虚幻感知，特别是在延迟潜伏期活动方面。
