Sridharan Devarajan, Levitin Daniel J, Chafe Chris H, Berger Jonathan, Menon Vinod
Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA.
Neuron. 2007 Aug 2;55(3):521-32. doi: 10.1016/j.neuron.2007.07.003.
The real world presents our sensory systems with a continuous stream of undifferentiated information. Segmentation of this stream at event boundaries is necessary for object identification and feature extraction. Here, we investigate the neural dynamics of event segmentation in entire musical symphonies under natural listening conditions. We isolated time-dependent sequences of brain responses in a 10 s window surrounding transitions between movements of symphonic works. A strikingly right-lateralized network of brain regions showed peak response during the movement transitions when, paradoxically, there was no physical stimulus. Model-dependent and model-free analysis techniques provided converging evidence for activity in two distinct functional networks at the movement transition: a ventral fronto-temporal network associated with detecting salient events, followed in time by a dorsal fronto-parietal network associated with maintaining attention and updating working memory. Our study provides direct experimental evidence for dissociable and causally linked ventral and dorsal networks during event segmentation of ecologically valid auditory stimuli.
现实世界为我们的感觉系统提供了源源不断的未分化信息。在事件边界对这些信息流进行分割,对于物体识别和特征提取来说是必要的。在此,我们研究了在自然聆听条件下,完整音乐交响曲中事件分割的神经动力学。我们在交响作品乐章之间的过渡周围的10秒窗口内,分离出了随时间变化的大脑反应序列。一个显著的右侧化脑区网络在乐章过渡期间显示出峰值反应,而此时反常的是没有物理刺激。基于模型和无模型的分析技术为乐章过渡时两个不同功能网络的活动提供了趋同证据:一个与检测显著事件相关的腹侧额颞网络,随后是一个与维持注意力和更新工作记忆相关的背侧额顶网络。我们的研究为在生态有效听觉刺激的事件分割过程中,可分离且因果相关的腹侧和背侧网络提供了直接的实验证据。