Figure 5. Longitudinal trends of cosine similarity.

(A) Median(CS) as a function of T1 and $\Delta \mathsf{T}$ (same as Figure 4F); 6 × 6 week Bins used for longitudinal comparisons are highlighted. Median(CS) was significantly higher in Bin 2 than in Bin 1 (p = 1.55 × 10⁻¹¹⁵) and significantly lower in Bin 3 than Bin 1 (p = 0.05, Kruskal-Wallis test).

(B) CS decreases with time passage $(\Delta \mathsf{T})$. To have comparable numbers of cells for different values of $\Delta \mathsf{T}$, we restricted this analysis to pairs of sessions with $\mathsf{T}1\le 6$ weeks. For each day, we computed median(CS). Here, the radius of each circle is proportional to the number of cells. We fitted data with a drift model $\mathsf{CS}(\Delta \mathsf{T})=a_0+a_1{\Delta \mathsf{T}}^{1∕2}$ (weighing data points by the number of cells) and obtained $a_0=0.6835$ and $a_1=-1.697{10}^{-3}{\text{day}}^{-1∕2}$. Red dashed lines indicate the 95% confidence interval. For the same population, we also computed $b=\mathsf{median}({\mathsf{CS}}_{\text{mismatched cells}})=0.622821$ (green dashed line). Thus, we estimated the time necessary for full reorganization, $\Delta {\mathsf{T}}_{\mathsf{FR}}=1,278$ days.

(C) CS increases with task experience (T1). This analysis was restricted to pairs of sessions with $\Delta \mathsf{T}\le 6$ weeks. The red line was obtained from the fit $\mathsf{CS}(\mathsf{T}1)=a_0+a_1\mathsf{T}{1}^{1∕2}$. The green dashed line indicates the median(CS) obtained for mismatching cells.

(D) CS and choice accuracy (population). Each dot represents one session, and the line was derived from a linear regression (p = 0.04). The color of the dot represents T3 (see color bar). In the inset, dots represent 25-day bins, and colors indicate T3.

(E) CS, choice accuracy, and experience in the task (individual animals). Axes represent T3 (x axis) and variable X (y axis), and each data point represents one session. Different colors indicate different animals, and solid lines were derived from an ANCOVA (independent lines). For 11 of 12 animals, the two measures were positively correlated.