Identifying response features suitable for building a factor model.

18 measures were chosen to capture the variation observed across the entire population of ELL pyramidal cell neurons in response to a communication signal (i.e. “small chirp”) occurring at different phases (0 90 180 and 270 degrees) of a continuous beat cycle. Measures are described and their origin within the complete stimulus waveform are indicated. Beat cycles (1–2) precede chirp onset while beat cycles (2–4) proceed the 100ms chirp window following chirp onset. The “data type” refers to the distinct stages of preprocessing from which the 18 measures originate (spike times, cycle histogram or PSTH). The total number of measures considered “Number per neuron”, and of those, the ones that are normally distributed are tallied. The identities of the stimuli (i.e. chirp phase or beat) from which the normally distributed measures belong are indicated. Collinear relationships among this subset of measures are identified. From the collinear pairs of measures identified one was randomly chosen for removal to yield the final features used in CFA classification which are similarly tallied.本研究选取18项指标，以捕捉全部ELL锥体细胞神经元（ELL pyramidal cell neurons）群体在响应通信信号（即"短啭鸣"）时的变异特征，该信号出现于连续搏动周期的0°、90°、180°及270°四个不同相位。本研究对各项指标进行了详述，并标注了其在完整刺激波形中的起源位置。连续搏动周期的1–2阶段位于啭鸣发作之前，而2–4阶段则处于啭鸣发作后的100ms啭鸣窗口时段内。此处的"数据类型"指18项指标所源自的三类预处理阶段：锋电位时刻、周期直方图，以及刺激后时间直方图（Peristimulus Time Histogram, PSTH）。本研究统计了被纳入"每神经元指标数"范畴的指标总数量，并对其中符合正态分布的指标进行了计数；同时标注了这些正态分布指标所对应的刺激来源属性，即啭鸣相位或搏动周期。研究团队识别出该正态分布指标子集内的共线性关联，随后从识别出的共线性指标对中随机移除其中一项，以得到最终用于验证性因子分析（Confirmatory Factor Analysis, CFA）分类的特征集，并对该特征集进行了同等的计数统计。