Bout Length.

A “bout” of one state in one region begins when that region enters that state and ends when that region moves to another state. We determined the duration of each bout for the hippocampus and the cortex by computing the number of 30-s epochs within the bout and dividing by two to yield a length in minutes. It should be noted that some bout lengths were underestimated, as epochs overwhelmed with artifacts were marked as “unscored” and thus, could interrupt continuous bouts. Statistical comparisons were completed in RStudio using the nlme library (63). The linear mixed effects regression model was fit using the maximum likelihood estimation with participant random intercepts and region fixed effects. The region fixed effects indicate the average difference between regions and were the primary focus of this analysis. Further details on statistical analyses can be found in SI Appendix.

Similarly, bout lengths were calculated as described above for bouts of each possible state pair between the hippocampus and cortex.