Attentional Mechanisms in Multisensory Environments

我们选择性地将注意力集中在我们感觉环境的元素上的能力是一种关键的认知 使我们能够增强对高优先级刺激的处理的功能。一个经典的例子就是“鸡尾酒”。 派对效应，即一个人可以有选择地专注于一个特定的发言者，而忽略其他发言者 交谈。在视觉上，注意视野的特定区域会导致更快和更好的检测 以及对该区域刺激的辨别。 电生理和血流动力学脑成像研究都表明，自上而下的执行 注意机制可以影响特定通道大脑皮层的早期感觉加工。最新研究 在人类中使用事件相关功能磁共振(FMRI)表明在大脑中存在额顶神经网络。 视觉注意力的执行控制。然而，到目前为止，相对较少的工作研究了注意力是如何 在感官形式之间切换或协调。因此，目前还不清楚是哪种大脑机制， 区域和控制注意力的资源是超通道的，并且是特定于通道的。此外，真正的 对象，包括鸡尾酒会上的演讲者，具有需要参与的多感官特征， 可感知的，并被整合的。因为多感官整合涉及到从 不同的感觉通道，尚不清楚相同的注意机制是否会在 多感官环境，如在单一感官环境中使用的。例如，注意一个功能或 多感官对象(例如，说话者的面部)的方面可能导致跨模式传播 注意(例如，包括说话者的声音)。 本课题提出将事件相关电位(ERPs)和事件相关功能磁共振相结合进行研究 注意力在多感官环境中运作的机制。这将包括研究 执行控制机制和大脑回路，在不同的感觉之间协调和切换注意力 方式，以及注意如何影响和相互作用的多感官的处理和整合 刺激物。记录注意任务期间脑活动的事件相关电位和功能磁共振测量将显示 只有辅助多感官注意操作的大脑区域，而且还有它们的时间和顺序 激活，从而增强了我们对基本机制的理解。注意力缺陷是关键 各种神经障碍和精神疾病的组成部分，从而阐明了

Our ability to selectively focus attention on elements of our sensory environment is a critical cognitive function that enables us to enhance the processing of high priority stimuli. A classic example is the "cocktail party" effect, in which a person can focus selectively on a particular speaker while tuning out other conversations. In vision, attending to a particular region of the visual field results in faster and better detection and discrimination of stimuli in that region. Both electrophysiological and hemodynamic brain imaging studies have shown that top-down executive attentional mechanisms can influence early sensory processing in modality-specific cortices. Recent studies using event-related functional MRI (fMRI) in humans have implicated a fronto-parietal network in the executive control of visual attention. As yet, however, relatively little work has investigated how attention is switched or coordinated between sensory modalities. Thus, it is not yet clear which brain mechanisms, regions, and resources controlling attention are supramodal and which are modality specific. Moreover, real objects, including speakers at cocktail parties, have multisensory characteristics that need to be attended, perceived, and integrated. Because multisensory integration involves synthesis of information derived from different sensory channels, it is not clear that the same attentional mechanisms will be operative in a multisensory environment as are employed in a unisensory situation. For example, attention to one feature or aspect of a multisensory object (e.g., the face of a speaker) might lead to a cross-modal spreading of attention (e.g., to encompass the speaker's voice). The present project proposes to combine event-related potentials (ERPs) and event-related fMRI to study the mechanisms by which attention operates in multisensory environments. This will include the study of executive control mechanisms and brain circuits that coordinate and switch attention between different sensory modalities, as well as how attention influences and interacts with the processing and integration of multisensory stimuli. Recording both ERP and fMRI measures of brain activity during the attentional tasks will reveal not only the brain areas that subserve multisensory attentional operations, but also the timing and sequence of their activations, thereby enhancing our understanding of the underlying mechanisms. Attentional deficits form key components of a variety of neurological disorders and mental illnesses, and thus elucidating the basic