Heterogeneity of functional activation during memory encoding across hippocampal subfields in temporal lobe epilepsy

► We studied functional activation in hippocampal subfields during memory encoding. ► Activation was greater in controls than in temporal lobe epilepsy patients. ► Activation was greater in patients' non-epileptogenic side than epileptogenic side. ► Strongest effects were seen in anterior hippocampus and dentate gyrus. ► DG was more active than CA1 in controls, but not in patients' epileptogenic side.