Modifying Brain Oscillations to Drive Perception

认知神经科学中的一个重要问题是大脑振荡是否与认知活动有因果关系，或者它们是否代表一种附带现象。在这种情况下，我们将测试关于振荡（在θ， α和β波段）与视觉注意选择和感知之间关系的假设。我们将测试枕顶叶区域的α波段振荡是否调节左右视野的视觉检测，从而根据视觉信息的空间位置选择视觉信息。-枕顶叶区域的β和θ波段振荡调节对象/场景中局部与全局特征的提取。这将通过对人类大脑区域进行频率特定的、有节奏的刺激，并通过评估其电生理和感知后果来解决。一些创新的发展已经从大脑绘图中出现，比如读心术。当一个人被要求放松（醒着休息）时，大脑活动会有很大的波动。这在特定的神经网络中以有组织的模式发生。不是随机的——因此很可能反映出不同心理活动的盛衰。此外，活动振荡模式的自发波动似乎会影响行为，因为它们与即将到来的任务表现共变。因此，大脑的瞬间状态可以从大脑映射中推断出来，这可以用来预测即将发生的行为。我们研究了直接皮层刺激（绕过感觉输入）可以在多大程度上诱导特定的大脑活动模式来改变任务表现。我们的方法是基于我们实验室的发现，振荡活动的特定特征预测即将到来的感知。我们将使用最新的技术对这些特定频率的直接（经颅）脑刺激来改变注意力和感知。该研究的一个组成部分是确定最有效的实验方案，以优化我们通过直接振荡刺激驱动注意力和感知的方法。这将涉及刺激频率和刺激区域的特定参数修改，作为持续大脑节律的功能。另一个重要的组成部分是测试注意力和感知模型。将有节奏的神经元刺激与感知联系起来将推进大脑振荡功能的理论，并探索如何将大脑功能偏向所需方向的新思路（例如神经康复）。

An important question in cognitive neuroscience is whether brain oscillations are causally related to cognitive activities or whether they represent epiphenomena. In this context, we will test hypotheses on the relationship between oscillations (in the theta, alpha and beta bands) and visual attentional selection and perception. We will test whether: - alpha-band oscillations over occipito-parietal areas regulate visual detection across the left and right visual fields for selecting visual information on the basis of its spatial location. - beta- and theta-band oscillations over occipito-parietal areas regulate the extraction of local versus global features within objects/scenes. This will be addressed by frequency-specific, rhythmic stimulation of human brain areas and by assessing its electrophysiological and perceptual consequences. Several innovative developments have emerged from brain mapping, such as mind reading. When an individual is asked to relax (wakeful rest), there is substantial fluctuation of brain activity. This occurs in organized patterns along specific neuronal networks--i.e. not randomly--and is thus likely to reflect the waxing and waning of distinct mental activities. In addition, spontaneous fluctuations in oscillatory patterns of activity seem to impact behaviour, because they are shown to co-vary with forthcoming task performance. Thus, momentary brain state can be inferred from brain mapping, and this can be used to predict imminent behaviour. We study to what extent specific patterns of brain activity can be induced by direct cortical stimulation (bypassing sensory input) to alter task performance. Our approach is based on findings in our laboratories that specific signatures of oscillatory activity predict forthcoming perception. We will use up-to-date techniques for direct (transcranial) brain stimulation at these specific frequencies to modify attention and perception. One component of the research is to identify the most effective experimental protocols to optimize our approach of driving attention and perception by direct oscillatory stimulation. This will involve specific parametric modifications of stimulation frequencies and stimulation regions as a function of ongoing brain rhythms. Another important component is to test models of attention and perception. Linking rhythmic neuronal stimulation to perception will advance theories on the functionality of brain oscillations and probe new ideas of how to bias brain function in desired direction (e.g for neurorehabilitation).