Attentional Mechanisms in Multisensory Environments

描述（由申请人提供）：我们有选择地将注意力集中在感官环境元素上的能力是一项关键的认知功能，使我们能够增强对高优先级刺激的处理。一个经典的例子是“鸡尾酒会”效应，一个人可以选择性地专注于一个特定的演讲者，而忽略其他谈话。在视觉方面，专注于视野的特定区域会更快更好地检测和辨别该区域的刺激。电生理和血流动力学脑成像研究表明，自上而下的执行注意机制可以影响模式特异性皮层的早期感觉加工。最近使用事件相关功能磁共振成像（fMRI）对人类进行的研究表明，在视觉注意的执行控制中存在额顶叶网络。然而，迄今为止，研究注意力如何在感觉模式之间转换或协调的工作相对较少。因此，目前尚不清楚控制注意力的大脑机制、区域和资源是超模态的，哪些是模态特异性的。此外，真实的物体，包括鸡尾酒会上的演讲者，具有多感官特征，需要参与、感知和整合。由于多感觉统合涉及来自不同感觉通道的信息的综合，因此尚不清楚多感觉环境中的注意机制是否与单感觉环境中的注意机制相同。例如，对多感官对象的一个特征或方面的关注（例如，说话者的脸）可能导致注意力的跨模态传播（例如，包括说话者的声音）。本项目拟结合事件相关电位（event- relevant potential, ERPs）和事件相关功能磁共振成像（event- relevant fMRI）来研究多感觉环境下注意力运作的机制。这将包括对执行控制机制和大脑回路的研究，这些机制和大脑回路在不同的感觉模式之间协调和切换注意力，以及注意力如何影响和相互作用于多感觉刺激的处理和整合。记录注意力任务期间大脑活动的ERP和fMRI测量结果，不仅可以揭示支持多感觉注意力操作的大脑区域，还可以揭示它们激活的时间和顺序，从而增强我们对潜在机制的理解。注意缺陷是各种神经系统疾病和精神疾病的关键组成部分，因此阐明了其基本机制。

DESCRIPTION (provided by applicant): 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 mechanism.