Intrinsic neuronal interactions versus external modulation of correlations
Neuronal correlations; Surrogate analysis; Residual correlations; Hippocampus; Memory
Correlations between neuronal spike trains can arise from intrinsic interactions or shared modulation by internal network states and external inputs, making their interpretation non-trivial. In this work, we propose a surrogate-based framework to quantify the portion of observed coactivity explained by known modulatory variables and to separate it from residual correlations not accounted for by these factors. Simulations demonstrate that this approach reliably distinguishes shared modulation from other sources of coordinated activity. Future applications to hippocampal data will investigate whether residual correlations during behavior predict memory reactivation during sleep.