The brain basis for episodic memory: insights from functional MRI, intracranial EEG, and patients with epilepsy

This article reviews the contributions that functional magnetic resonance imaging (fMRI), intracranial electroencephalography (iEEG), and patient studies have made to our current understanding of how memory functions arise from the brain. First, we briefly discuss the current classification of different memory systems and their neuroanatomical correlates, focusing on episodic memory and evidence from lesion studies. We then survey both fMRI and iEEG studies of memory function. For each modality, we discuss its physiological basis, as well as point out key studies that have led to new insights regarding memory. Advantages and disadvantages of each brain mapping modality are addressed. Wherever appropriate, we point out implications these studies have for the treatment of patients with epilepsy. We conclude this review with further discussion regarding the potential for combining fMRI and iEEG techniques in future investigations of memory function.