Neuroscience Statistics Research Lab, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Neural Comput. 2012 Oct;24(10):2543-78. doi: 10.1162/NECO_a_00334. Epub 2012 Jun 26.
The moving bar experiment is a classic paradigm for characterizing the receptive field (RF) properties of neurons in primary visual cortex (V1). Current approaches for analyzing neural spiking activity recorded from these experiments do not take into account the point-process nature of these data and the circular geometry of the stimulus presentation. We present a novel analysis approach to mapping V1 receptive fields that combines point-process generalized linear models (PPGLM) with tomographic reconstruction computed by filtered-back projection. We use the method to map the RF sizes and orientations of 251 V1 neurons recorded from two macaque monkeys during a moving bar experiment. Our cross-validated goodness-of-fit analyses show that the PPGLM provides a more accurate characterization of spike train data than analyses based on rate functions computed by the methods of spike-triggered averages or first-order Wiener-Volterra kernel. Our analysis leads to a new definition of RF size as the spatial area over which the spiking activity is significantly greater than baseline activity. Our approach yields larger RF sizes and sharper orientation tuning estimates. The tomographic reconstruction paradigm further suggests an efficient approach to choosing the number of directions and the number of trials per direction in designing moving bar experiments. Our results demonstrate that standard tomographic principles for image reconstruction can be adapted to characterize V1 RFs and that two fundamental properties, size and orientation, may be substantially different from what is currently reported.
运动棒实验是一种经典的方法，用于描述初级视觉皮层（V1）神经元的感受野（RF）特性。目前分析从这些实验中记录的神经尖峰活动的方法没有考虑到这些数据的点过程性质和刺激呈现的圆形几何形状。我们提出了一种新的分析方法，用于映射 V1 的感受野，该方法将点过程广义线性模型（PPGLM）与滤波反投影计算的层析重建相结合。我们使用该方法来映射从两只猕猴在运动棒实验中记录的 251 个 V1 神经元的 RF 大小和方向。我们的交叉验证拟合优度分析表明，PPGLM 比基于由尖峰触发平均或一阶 Wiener-Volterra 核方法计算的率函数进行的分析更准确地描述了尖峰序列数据。我们的分析导致了一种新的 RF 大小定义，即尖峰活动明显高于基线活动的空间区域。我们的方法产生了更大的 RF 大小和更尖锐的方向调谐估计。层析重建范式进一步表明，在设计运动棒实验时，选择方向数量和每个方向的试验数量的有效方法。我们的结果表明，可以适应标准的层析重建原则来描述 V1 的 RF，并且两个基本属性，大小和方向，可能与当前报告的有很大不同。
