ENCODING OF VISUAL INFORMATION IN LGN FIRING PATTERNS

这些实验的目的是研究LGN神经元对不同类型的视觉刺激反应的放电模式的重复性。在我之前的理论工作中，基于实验合作者收集的数据，我证明了通过简单地对LGN棘波序列进行线性滤波，可以近似地重建随机变化的视觉刺激。此外，我还表明，LGN细胞发出的独特脉冲有效地编码了视觉信息。在过去两年的实验中，我一直在研究个体LGN对动态视觉刺激反应的重复性。在我生命的最后一年，我计划将这项工作扩展到丘脑神经元群体如何集体编码自然刺激的问题上。(1)我将研究视觉刺激集合的统计数据如何影响单个LGN反应的重复性。将对时间和时空自然刺激的反应重复性进行测量。在对照实验中，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响应中的噪声是否与其他小区响应中的噪声共享或独立于其他小区响应中的噪声。为了实现这一点，我将比较一个细胞和另一个同时记录的细胞的试验响应变化。这些研究将阐明单个细胞的反应如何共同作用，以编码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.