Abstract
Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory.
•Deep brain stimulation in the entorhinal region and hippocampus impairs memory•Stimulation at 50 Hz impairs both spatial and verbal memory encoding•A causal role for the human medial temporal lobe in memory encoding is demonstrated
Jacobs et al. found that electrical stimulation in the entorhinal region and hippocampus impaired spatial and verbal memory. These findings show that these regions have a causal role in memory but suggest we need improved stimulation protocols for memory improvement.
