A gap in inter-regional synchrony was considered statistically significant if for any given frequency band the inter-regional (entorhinal–hippocampal) synchrony was lower than both intra-regional synchronies (i.e., within entorhinal cortex and within hippocampus) at the p = 0.05 significance level of the two-sided Wilcoxon test. Assuming the one-sided probabilities for this hypothesis (EC–Hi lower than EC–EC and EC–Hi lower than Hi–Hi) to be independent and including a Bonferroni correction for testing multiple (six) frequency bands, one obtains an effective significance value for a gap in synchrony defined in this way as p = 0.025 × 0.025 × 6 < 0.004. However, since one of the paired samples (EC–Hi) is used in both tests, the assumption of independent probabilities is not valid. We therefore used Monte Carlo simulations based on samples of pseudorandom numbers to estimate the actual empirical p-value of our combined criterion (including the Bonferroni correction) as p < 0.024.
