ENCODING OF VISUAL INFORMATION IN LGN FIRING PATTERNS

这些实验的目的是研究LGN神经元在不同类型的视觉刺激下放电模式的可重复性。在我之前的理论工作中，基于实验合作者收集的数据，我证明了随机变化的视觉刺激可以通过简单的线性过滤LGN尖峰序列来近似重建。此外，我还展示了LGN细胞发出的独特脉冲有效地编码了视觉信息。在我自己的实验中，在过去的两年里，我一直在研究单个LGN对动态视觉刺激反应的可重复性。在我的最后一年，我计划将这项工作扩展到丘脑神经元群体如何共同编码自然刺激的问题。(1)我将研究视觉刺激集合的统计如何影响单个LGN反应的可重复性。将测量时间和时空自然刺激的反应再现性。在控制实验中，我会操纵自然刺激来改变刺激的强度分布、频谱或对比度。(2)我将研究单个LGN反应中的噪声是与其他细胞反应中的噪声共享还是独立。为了做到这一点，我将逐个比较一个细胞与另一个同时记录的细胞的试验反应变化。这些研究将揭示单个细胞的反应如何协同工作来编码LGN中的自然视觉场景。

The goal of these experiments is to study the reproducibility of firing patterns in LGN neurons in response to different types of visual stimulation. In my previous theoretical work, based on data collected by experimental collaborators, I showed that a randomly varying visual stimulus could be approximately reconstructed by simply linearly filtering an LGN spike train. Moreover, I showed that the distinctive bursts fired by LGN cells encoded visual information efficiently. In my own experiments during the past two years, I have been studying the reproducibility of individual LGN responses to dynamic visual stimuli. In my final year, I plan to extend this work to the problem of how a population of thalamic neurons collectively encodes natural stimuli. (1) I will study how the statistics of the visual stimulus ensemble affects the reproducibility of individual LGN responses. Response reproducibility will be measured for both the temporal and spatio-temporal natural stimuli. In control experiments, I will manipulate natural stimuli to vary the intensity distribution, the frequency spectrum, or the contrast of the stimuli. (2) I will study whether the noise in an individual LGN response is shared with, or independent from, the noise in other cells responses. To accomplish this I will compare the trial by trial response variations of one cell with those of another simultaneously recorded cell. These studies will shed light on how the responses of individual cells work together to encode natural visual scenes in the LGN.