Principal components analysis (PCA) of early part of response data (t<100 ms) for example on-center Y and X neurons in <b>Figs. 1</b> and <b>2</b>.

Abstract

<p><b>A</b>,<b>B</b>, 1^st and 2^nd principal components, respectively, for the Y-neuron response data, i.e., contributions from terms with <i>n = 1</i> and <i>n = 2</i> in Eq. (3). <b>C</b>, Sum of contributions from two first principal components (and background activity) for Y neuron. <b>D</b>, Deviation between experimental results for Y neuron and PCA results in (C). Error <i>ε</i> (cf. Eq. 1) is 0.044. <b>E</b>, Fitted transient temporal function <i>F_t1</i>(<i>t</i>) (Eq. 11, blue dashed line) to 1^st temporal PCA component (blue solid line), and fitted transient temporal function <i>F_t2</i>(<i>t</i>) (Eq. 12, green dashed line) to 2^nd temporal PCA component (green solid line) for early part ( t<97.5 ms) of Y-neuron data. <b>F</b>, Blue dashed line: Fitted DOG spatial functions (Eq. 10) to 1^st spatial PCA component of early part (t<97.5 ms) of Y-neuron data (blue solid line). Green dashed line: Corresponding DOG function fit to the 2^nd spatial PCA component (green solid line). The best fit of a DOG function (red dashed line) to the 1^st spatial PCA component of the <i>last</i> part of the Y-neuron data is also shown (red line). <b>G–L</b>, Same as (A)–(F) for X-neuron response data. The deviation between experimental results and PCA results (I) corresponds to an error <i>ε</i> = 0.021.</p