Studies of Attention Using Combined ERPs and fMRI

描述(由申请人提供)：我们选择性地将注意力集中在感觉环境元素上的能力是一种关键的认知功能，使我们能够增强对高优先级刺激的处理。电生理和血液动力学脑成像研究都表明，额叶和顶叶皮质的脑区网络在传递自上而下的注意控制以影响低水平感觉皮质的处理方面发挥了作用。在之前的授权期，我们使用功能磁共振成像(FMRI)和事件相关电位(ERPs)来帮助描绘在注意的自愿定向过程中这个控制网络中特定区域的激活的神经级联，以及自愿注意调节感觉皮质处理的各种方式。然而，注意力促进我们在现实世界中表现的机制的许多方面仍然不清楚。例如，我们以前的大部分工作都集中在自愿注意的机制上，当它以持续的方式定向到特定位置或刺激通道时，或者当它只需要相对缓慢地定向时。然而，对于注意力的快速空间转移，神经控制机制似乎可能在某些重要方面有所不同。此外，还有许多其他基本的和生态上重要的方法可以引起注意，以加强对相关刺激的处理。例如，注意力转移和注意力控制也可以通过观察个体的眼睛凝视、视觉弹出刺激和刺激冲突来启动，所有这些似乎都会以一种比内源性教学线索更快、更自动的方式诱导注意力的投入。然而，在这些其他情况下，潜在的注意力控制和影响的神经过程的时间级联还没有被描绘出来。在这项拨款的下一阶段，我们建议继续我们对注意力的神经机制的程序性研究，以一组新的研究针对这些调用注意力控制和影响的其他基本方式。这些研究将包括：(1)自愿性和凝视线索触发的视觉空间注意的快速转移；(2)复杂视觉场景中空间注意的转移和聚焦；(3)调用注意来检测和解决冲突的视觉刺激信息。和以前一样，我们计划结合ERPs、EEG、fMRI和行为测量来进行这些研究，目的是描绘这些认知功能涉及的神经过程和网络动力学的时间、顺序和位置，从而深入了解潜在的机制。

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. Both electrophysiological and hemodynamic brain imaging studies have implicated a network of brain areas in the frontal and parietal cortices as playing a role in imparting top-down attentional control to influence processing in low-level sensory cortices. In the previous grant period we used functional MRI (fMRI) and event-related potentials (ERPs) to help delineate the neural cascade of activations in specific regions in this control network during the voluntary orienting of attention, as well as various of the ways in which voluntary attention can modulate processing in the sensory cortices. However, many facets of the mechanisms by which attention facilitates our performance in the real world remain unclear. For example, most of our previous work focused on the mechanisms of voluntary attention when it was either directed in a sustained way to a particular location or stimulus channel, or when it needed to be oriented only relatively slowly. It seems likely, however, that for rapid spatial shifts of attention the neural control mechanisms differ in some important ways. Moreover, there are numerous other fundamental and ecologically important ways in which attention is invoked for enhancing the processing of relevant stimuli. For example, attentional shifts and attentional control can also be initiated by viewing an individual's eye gaze, by visual-popout stimuli, and by stimulus conflict, all of which appear to induce the engagement of attention in a faster and more automatized way than with endogenous instructional cues. However, the temporal cascade of the neural processes underlying attentional control and influence in these other circumstances has yet to be delineated. In the next period of this grant, we propose to continue our programmatic investigation of the neural mechanisms of attention with a new set of studies directed toward these other fundamental ways in which attentional control and influence is invoked. These will include study of: (1) the rapid shifting of both voluntary and gaze-cue-triggered visual spatial attention, (2) the shifting and focusing of spatial attention within a complex visual scene; and (3) the invocation of attention for detecting and resolving conflicting visual stimulus information. As before, we plan to combine ERPs, EEG, fMRI, and behavioral measures to perform these studies, with the aim to delineate the timing, sequence, and location of the neural processes and network dynamics involved in these cognitive functions, thereby gaining insight into the underlying mechanisms.