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用于估计和评估非泊松神经编码模型的时间重标方法

Time-rescaling Methods for the Estimation and Assessment of Non-Poisson Neural Encoding Models
课程网址: http://videolectures.net/nips09_pillow_trme/  
主讲教师: Jonathan Pillow
开课单位: 德克萨斯大学
开课时间: 2010-01-19
课程语种: 英语
中文简介:
最近关于神经反应的统计建模的工作集中于调制的更新过程,其中尖峰率是刺激和最近的尖峰历史的函数。通常,这些模型通过以下任一方式结合尖峰历史依赖性:(A)条件泊松过程,其速率取决于尖峰列车历史的线性投影(例如,广义线性模型);或(B)调制的非泊松更新过程(例如,非均匀伽马过程)。在这里,我们表明这两种方法可以结合起来,从而产生神经尖峰列车的{\ it条件更新}(CR)模型。该模型捕获实时和重新缩放的时间效应,并且可以通过使用时间重新缩放定理的简单应用来最大似然拟合[1]。我们表明,对于任何已调制的更新过程模型,只有在更新密度的某些限制条件下,对数似然是凹的线性滤波器参数(排除了许多流行的选择,例如带有$ \ kappa \ neq1 $的伽玛),表明真实时间历史效应比非泊松更新属性更容易估计。此外,我们表明基于时间重新调整定理[1]的拟合优度测试量化了相对时间效应,但是不能可靠地评估尖峰预测或刺激响应建模的准确性。我们通过应用于真实和模拟神经数据来说明CR模型。
课程简介: Recent work on the statistical modeling of neural responses has focused on modulated renewal processes in which the spike rate is a function of the stimulus and recent spiking history. Typically, these models incorporate spike-history dependencies via either: (A) a conditionally-Poisson process with rate dependent on a linear projection of the spike train history (e.g., generalized linear model); or (B) a modulated non-Poisson renewal process (e.g., inhomogeneous gamma process). Here we show that the two approaches can be combined, resulting in a {\it conditional renewal} (CR) model for neural spike trains. This model captures both real and rescaled-time effects, and can be fit by maximum likelihood using a simple application of the time-rescaling theorem [1]. We show that for any modulated renewal process model, the log-likelihood is concave in the linear filter parameters only under certain restrictive conditions on the renewal density (ruling out many popular choices, e.g. gamma with $\kappa \neq1$), suggesting that real-time history effects are easier to estimate than non-Poisson renewal properties. Moreover, we show that goodness-of-fit tests based on the time-rescaling theorem [1] quantify relative-time effects, but do not reliably assess accuracy in spike prediction or stimulus-response modeling. We illustrate the CR model with applications to both real and simulated neural data.
关 键 词: 神经反应; 泊松过程; 最大似然
课程来源: 视频讲座网
最后编审: 2020-06-08:yumf
阅读次数: 54