The role of alpha-band oscillations in feature-based selective attention.

描述(由申请人提供)： 当偷偷地注意到预计会出现行为相关信息的空间区域时，对出现在这些位置的视觉刺激的处理得到增强。相反，如果一个空间区域被认为是令人分心的事件的中心，那么对发生在那里的刺激的处理就会减弱。后一种抑制过程反映在脑电中阿尔法频段(8-15赫兹)振荡功率的视网膜定位特异性增加。基于动物中类似振荡的细胞生理学，已经提出α可能作为一种功能门控机制。重要的是，已发现的有助于这些节律产生的神经区网络包括额叶、顶叶和枕叶视觉区域以及丘脑核团，这些区域与几个有影响力的注意操作理论所涉及的区域是相同的。需要对阿尔法频段测量进行进一步的表征，以确定它在多大程度上是注意展开机制的附属物，或者更确切地说，是内源性注意机制本身。到目前为止，选择性注意的阿尔法波段测量只针对空间注意进行了表征。然而，也可以将注意力部署到非空间视觉特征，例如颜色或运动参数，以促进后续刺激与所关注的特征的处理，而与其空间位置无关。本项目的目标是通过在纯基于特征的注意任务中测试阿尔法频段注意测量的时空特性来进一步表征阿尔法频段注意测量。为此，一个经典的视觉空间选择性注意任务将转变为一个纯粹的特征领域。一个象征性的提示将告诉参与者即将到来的刺激的任务相关特征，而大脑的电活动被记录在头皮上。提示刺激和命令刺激将被一段时间间隔分开，在这段时间内没有刺激发生，在此期间大脑活动反映了内部的准备注意过程。通过改变线索的参数(如其信息性)和命令性刺激(如其持续时间或连贯性)，将创建不同的注意集对其有利的背景，从而允许评估阿尔法波段功率增加的程度和限制，作为在有偏见的竞争模型中的抑制机制。 公共卫生相关性： 项目叙述将注意力偏向于环境中与行为相关的方面的能力对良好的心理健康至关重要。正常注意功能的紊乱，特别是抑制无关信息的能力，已被认为与许多精神障碍有关，如注意力缺陷障碍、自闭症谱系障碍和精神分裂症。该项目对理解正常注意抑制背后的神经生理机制的贡献将极大地促进涉及注意力的障碍的研究。这项工作与我们实验室正在进行的研究以及与自闭症谱系障碍和精神分裂症的合作者很好地吻合。

DESCRIPTION (provided by applicant): When covertly attending to regions of space where behaviorally relevant information is expected to occur, processing of visual stimuli appearing at those locations is enhanced. Conversely, if a region of space is expected to be a locus of distracting events, processing of stimuli occurring there is attenuated. This latter suppressive process is reflected by retinotopically specific increases of alpha-band (8-15Hz) oscillatory power in the electroencephalogram. Based on the cellular physiology of similar oscillations in animals, it has been proposed that alpha might serve as a functional gating mechanism. Importantly, the network of neural areas that have been found to contribute to the generation of these rhythms, which include frontal, parietal and occipital visual areas and thalamic nuclei are the same areas implicated in several influential theories of attentional operations. Further characterization of the alpha-band measure is needed to determine the extent to which it is epiphenomenal to attentional deployment mechanisms, or rather an endogenous attentional mechanism per se. To date, the alpha-band measure of selective attention has only been characterized with respect to spatial attention. However, attention can also be deployed to non-spatial visual features, such as color or motion parameters, facilitating the processing of subsequent stimuli with the attended feature, independently of its spatial location. The goal of this project is to further characterize the alpha-band attentional measure by testing its spatiotemporal properties in a purely feature-based attention task. To this end, a classic visual spatial selective attention task will be transformed into a purely featural domain. A symbolic cue will inform participants about a task-relevant feature of an upcoming stimulus, while electrical brain activity is recorded at the scalp. The cue and imperative stimuli will be separated by an interval during which no stimulation occurs, the brain activity during which reflects internal preparatory attentional processes. By varying parameters of the cue (such as its informativeness) and imperative stimuli (such as its duration or coherence) contexts will be created for which different attentional sets are advantageous, allowing the assessment of the extent and limits of alpha-band power increases as a mechanism for suppression in biased competition models. PUBLIC HEALTH RELEVANCE: Project Narrative The ability to bias attention in favor of behaviorally relevant aspects of the environment is critical for good mental health. Disruptions of normal attentional function, and in particular the ability to suppress irrelevant information, has been implicated in many psychiatric disorders such as attention deficit disorder, autism spectrum disorders and schizophrenia. The contributions of this project to understanding the neurophysiological mechanisms underlying normal attentional suppression will greatly advance research of disorders involving attention. This work dovetails nicely with ongoing research in our laboratory and with collaborators concerning autism spectrum disorders and schizophrenia.