ERPs and the Dynamics of Adaptive Attentional Control in the Prefrontal Cortex

在头皮上测量的脑电活动一直是认知和情绪信息处理研究的主要内容，使用两种策略：一种是使用EEG中正在进行的脑电波模式，另一种是使用EEG片段，称为事件相关电位，这些片段被时间锁定到重复的重要心理事件，例如对刺激的感知。 在这两种情况下，人们需要对许多试验进行平均以找到相关的一致模式，这导致这些传统方法的两个严重局限性：（1）由于头皮EEG表示来自各种皮层网络的信号的混合，因此难以具体了解在头皮处测量的活动与感兴趣的神经功能之间的关系;（2）没有关于这些神经功能在皮层区域之间的动态关系的信息。我们现在有办法解决这两个局限性，并使其实用的研究实验室和临床。我们建议，这些措施有希望比这两种情况下使用的标准评估措施更敏感。 我们的研究问题涉及与两个特定的大脑区域相关的过程-额叶皮层是使一个人的行为适应变化或意外情况的中心，以及视觉皮层，同时处理复杂的刺激，如人脸。我们已经证明了这些大脑区域与人格、大脑发育和视觉信息处理细节之间的关系，尽管存在上述限制，但所有这些都使用标准测量方法。然而，我们现在正在应用程序来映射额叶组织和视觉皮层之间的动态关系，我们认为这可以解释社会和认知因素如何影响早期视觉感知过程。我们还将在临床环境中应用这些技术，以捕获其他措施不太成功的神经系统疾病中的认知功能，例如在痴呆的早期阶段，脑震荡后综合征，以及对具有最低意识水平的个体的认知活动的评估。

Brain electrical activity as measured at the scalp has been a staple of research on cognitive and emotional information processing using two strategies: one uses ongoing brainwave patterns in the EEG and the other uses EEG segments, known as event-related potentials, that are time-locked to repeated important mental events such as the perception of a stimulus. In both cases, one needs to average over many trials to find the associated consistent patterns, resulting in two serious limitations of these traditional methods: (1) since the scalp EEG represents a mixture of signals from various cortical networks, it is difficult to be specific about the relationship between the activity measured at the scalp and the neural function of interest; and (2) there is no information available concerning the dynamic relations between these neural functions across regions of the cortex. We now have ways to address both these limitations and make them practical for both the research lab and the clinic. We propose that these measures have promise of being more sensitive than standard assessment measures used in either setting.** Our research questions involve processes associated with two specific brain regions - the frontal cortex that is central for adapting one's behaviour to changed or unexpected circumstances, and the visual cortex while processing complex stimuli such as human faces. We have demonstrated relations between these brain regions and personality, brain development, and specifics of visual information processing, all using standard measures despite the limitations indicated above. However, we are now applying procedures for mapping the dynamic relations between frontal lobe tissue and the visual cortex, which we think account for how social and cognitive factors influence early visual perceptual processes. We will also apply these techniques in clinical settings to capture cognitive functioning in neurological conditions where other measures have less success, such as in very early stages of dementia, post-concussive syndrome, and the assessment of cognitive activity in individuals with minimal levels of consciousness.**