Bushara K O, Grafman J, Hallett M
National Institute of Neurological Disorders and Stroke, Human Motor Control Section, and Cognitive Neuroscience Section, National Institutes of Health, Bethesda, Maryland 20892-1428, USA.
J Neurosci. 2001 Jan 1;21(1):300-4. doi: 10.1523/JNEUROSCI.21-01-00300.2001.
Intersensory temporal synchrony is an ubiquitous sensory attribute that has proven to be critical for binding multisensory inputs, sometimes erroneously leading to dramatic perceptual illusions. However, little is known about how the brain detects temporal synchrony between multimodal sensory inputs. We used positron emission tomography to demonstrate that detecting auditory-visual stimulus onset asynchrony activates a large-scale neural network of insular, posterior parietal, prefrontal, and cerebellar areas with the highest and task-specific activity localized to the right insula. Interregional covariance analysis further showed significant task-related functional interactions between the insula, the posterior thalamus, and superior colliculus. Based on these results and the available electrophysiological and anatomical connectivity data in animals, we propose that the insula, via its known short-latency connections with the tectal system, mediates temporally defined auditory-visual interaction at an early stage of cortical processing permitting phenomena such as the ventriloquist and the McGurk illusions.
跨感觉时间同步是一种普遍存在的感觉属性，已被证明对于整合多感觉输入至关重要，有时会错误地导致显著的感知错觉。然而，关于大脑如何检测多模态感觉输入之间的时间同步，我们知之甚少。我们使用正电子发射断层扫描来证明，检测听觉 - 视觉刺激起始异步会激活一个由岛叶、后顶叶、前额叶和小脑区域组成的大规模神经网络，其中最高且特定于任务的活动位于右侧岛叶。区域间协方差分析进一步显示，岛叶、丘脑后部和上丘之间存在显著的与任务相关的功能相互作用。基于这些结果以及动物中可用的电生理和解剖连接数据，我们提出，岛叶通过其与顶盖系统已知的短潜伏期连接，在皮层处理的早期阶段介导时间定义的听觉 - 视觉相互作用，从而产生诸如腹语术和麦格克错觉等现象。
