Electrical stimulation to control feedback modulation of perception

总结 视觉感知是视觉输入和注意状态的汇合。如何处理视觉输入， 在人类视觉皮层中所代表的信息在该领域中正以越来越高的准确性被捕获。然而，一个关键的 我们理解的差距是，来自高阶区域的自上而下的输入如何影响和塑造感官 处理，尤其是基于直接因果关系的理解。的长期目标 拟议的研究是开发因果扰动方法，调节视觉处理的方式， 模仿注意力过程为了实现这一目标，我们将使用电刺激来测试，完善，并扩大 反馈信息流到腹侧颞叶皮层（VTC）的定量模型。我们的研究 利用最近癫痫手术的临床转变，从脑表面记录皮质电描记术， 立体脑电图（sEEG）深度电极：sEEG提供了测量 VTC和电刺激来自脑回和沟顶叶、额叶和前部的反馈投射 颞区以及连接这些区域和VTC的白色物质通路。在目标1中，我们 确定刺激这些不同的反馈位置如何影响VTC中的神经元活动，并模拟 皮质柱模型中的VTC信号。VTC电极将在功能上与场景一起定位 感知任务和结构连接将从术前弥散MRI测量中识别 马约诊所的新型紧凑型3T扫描仪，具有高性能梯度和无失真成像。在 目的2，我们将确定最佳的刺激频率的反馈途径，VTC。电极 反馈通路将用不同的时间频率刺激，VTC中的测量将 用于表征最佳响应频率。在目标3中，我们将测试先前提出的预测 VTC中前馈驱动和反馈调制的模型。我们将在交付的同时呈现视觉场景 反馈通路的电刺激，并测量sEEG神经反应和行为 反应时间这种电刺激和视觉感知的结合使我们能够测试和完善一种 VTC和顶内沟之间的相互作用如何影响视觉处理的现存模型， 有助于视觉感知。总的来说，这一多学科的建议将提供一套经验性的 描述反馈途径对人类VTC的因果影响的测量和模型。这些 这些研究将为未来的研究提供基础，以设计基于扰动的策略， 人的注意力状况。

SUMMARY Visual perception is a confluence of visual input and attentional state. How visual inputs are processed and represented in human visual cortex is being captured with increasing accuracy in the field. However, a critical gap in our understanding is how top-down inputs from higher order areas influence and sculpt sensory processing—especially an understanding grounded in direct causal manipulations. The long-term goal of the proposed research is to develop causal perturbation methods that modulate visual processing in ways that mimic attentional processes. To achieve this goal, we will use electrical stimulation to test, refine, and extend a quantitative model of feedback information flow to the ventral temporal cortex (VTC). Our research leverages a recent clinical shift in epilepsy surgery from brain surface recordings with electrocorticography to stereo-electroencephalographic (sEEG) depth electrodes: sEEG provides unique opportunities to measure VTC and electrically stimulate feedback projections from gyral and sulcal parietal, frontal and anterior temporal regions as well as the white matter pathways that connect these areas to VTC. In Aim 1, we will determine how stimulating these different feedback locations affects neuronal activity in VTC and simulate VTC signals in a model of a cortical column. VTC electrodes will be localized functionally with a scene perception task and structural connections will be identified from preoperative diffusion MRI measurements on Mayo Clinic’s novel compact 3T scanner with high performance gradients and distortion free imaging. In Aim 2, we will determine the optimal stimulation frequencies for feedback pathways to VTC. Electrodes in feedback pathways will be stimulated with different temporal frequencies and measurements in VTC will be used to characterize optimal response frequencies. In Aim 3, we will test predictions of a previously proposed model of feedforward drive and feedback modulation in VTC. We will present visual scenes while delivering electrical stimulation of feedback pathways and measure changes in sEEG neural responses and behavioral reaction times. This combination of electrical stimulation and visual perception allows us to test and refine an extant model of how interactions between VTC and the intraparietal sulcus affect visual processing and contribute to visual perception. Overall, this multidisciplinary proposal will deliver a set of empirical measurements and models that describe the causal influence of feedback pathways on human VTC. These studies will provide the groundwork for future research to design perturbation based strategies that mimic human attentional conditions.