Fig. 2: Spontaneous activity patterns are similar to evoked activity patterns in lower but not higher visual areas.

a Two-photon calcium imaging is conducted in visual areas identified from widefield imaging. In each FOV, spontaneous and visually evoked activity is recorded for the identical set of cells. b Example cell image and cellular orientation map in V1. Experiments were repeated in 12 times and similar results were obtained. The cellular orientation map is calculated using the cells identified from the cell image (left). Scale bar, 100 μm. c Time courses of spontaneous activity for example cells. Comparison of spontaneous and evoked activity in V1 (d), V2 (e), and MT (f). Panel “Corr. Timecourses” shows a correlation between individual spontaneous frames and responses to single orientations or directions. Panel “FOV Activity” shows the average activity of all the cells in the FOV. Panels “Spont. Frame” and “Vis. Resp.” show an example spontaneous frame and a response to a single orientation that is most similar to the spontaneous frame. Two examples are shown for time points indicated by dotted lines in the time courses. g Cumulative plots showing the similarity of spontaneous frames and evoked activity. For each spontaneous frame, correlations with all single orientation or direction responses are calculated, then the maximum value is taken. Inset, a summary table of statistically significant difference [*, p < 0.05 (uncorrected), **, p < 0.05 (corrected by Bonferroni’s method), Wilcoxon’s Rank Sum test. P values (uncorrected, two-sided) are as follows: 0.880 (V1-V2), 3.69 × 10^–10 (V1-MT), 0.0129 (V1-mouse V1), 9.20 × 10^–12 (V2-MT), 0.0062 (V2-mouseV1), 2.15 × 10^–5 (MT-mouse V1)].