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Updated: Jan 7, 2026
Simultaneous Monitoring of Wireless Electrophysiology and Memory Behavioral Test as a Tool to Study Hippocampal Neurogenesis
Published on: August 20, 2020
Optimization of memory neurofeedback system utilizing intracranial electroencephalogram of the hippocampus
Ako Matsuhashi1, Seijiro Shimada1, Naoto Kunii2
1The University of Tokyo Hospital, Neurosurgery 7-3-1 Hongo Bunkyo, Tokyo 113-8655, Japan.
Objective:
Patients with temporal lobe epilepsy (TLE) suffer from epileptic seizures and memory decline. While focal resection eliminates seizures in 60-70% of patients, surgery carries the risk of further compromising memory. We hypothesized that hippocampal neurofeedback (NF) will induce targeted brain activity associated with memory function.
Methods:
Patients with intracranial electrodes implanted in bilateral hippocampi performed a memory NF task, developed specifically for this project. The NF task involved real-time analysis of hippocampal activity using the electrode in the less-affected hippocampus while conducting a memory task. Changes in theta activity and task performance were assessed.
Results:
The NF task was conducted in seven TLE patients. In five patients, theta activity increased significantly in the targeted hippocampus (Mann-Kendall test; p < 0.05). Mixed linear model analysis across all sessions revealed a significant increase in theta activity in the targeted hippocampus (p = 0.0032), with no significant change contralaterally (p = 0.19). Three additional TLE patients underwent random NF to assess if theta activity was induced merely by the encoding process, but none of them showed significant changes in theta activity.
Conclusion:
Memory NF task effectively induced targeted hippocampal activity in TLE patients.
Significance:
Hippocampal NF may enhance memory function in TLE patients prior to focal resection.
