In this study, we will use large-scale, long-term measurements of intracranial EEG and fMRI measurements to unveil the relationship between activity patterns in the hippocampal-cortical network and cognitive functions. Furthermore, we will use multi-site simultaneous neural recording in rats to unveil the causal relationship between cortical functional connectivity and hippocampal activity. By understanding the neurophysiological mechanisms of resting-state functional connectivity, we aim to elucidate the relationship between resting-state functional connectivity and cognitive functions and disease biomarkers as the dynamics of hippocampal-cortical networks.