(A, B) Examples of ridge-to-background ratios calculated from neurons with peak mean activity occurring within six 5 s time windows (from left to right: −10 s to −5 s, −9 s to −4 s, −8 s to −3 s, −7 s to −2 s, −6 s to −1 s, and −5 s to 0 s). Thirty-five (A) and fifteen (B) neurons were randomly chosen to calculate the ratios. Top, middle, and bottom panels are the superficial, middle, and deep areas of the mFrC, respectively. *p<0.05, **p<0.01, ***p<0.001, Wilcoxon rank-sum test. (C, D) Percentages of ridge-to-background ratios in which original data were significantly different (p<0.05, Wilcoxon rank-sum test) from shuffled data (blue, green, and red are the superficial, middle, and deep areas of the mFrC, respectively). Random chooses of 35 (C) and 15 (D) neurons to calculate the ratios were repeated 10,000 times. Blue line and circles, superficial area; red line and triangles, middle area; yellow line and squares, deep area.