Human Neural Activity during Learning and Memory
Jessica Edwards, Miguel Remondes, Adam Mamelak

While learning and memory are widely studied in a variety of systems, it is still rare to be able to examine these behaviors at the single cell level in humans. Working with a group of epileptic patients, we are able to record from individual neurons in alert and learning humans. Patients suffering from medically intractable epilepsy are resistant to drug therapies that are traditionally used for seizure control. Resection of the epileptogenic focus provides seizure relief. To localize the area for surgery, patients are implanted with up to twenty electrodes, including microwire, hybrid electrodes in the hippocampus and amygdala. The duration of the medical procedures allows us to monitor the electrical activity of cells in the hippocampus and amygdala for up to one week. Using a battery of neuropsychological tests, we are able to examine rapid learning and declarative memory. Tests we are currently using include three versions of the Recognition Memory Task: Faces, Objects and Words, a Continuous Visual Memory Task, Verbal Paired Associates and a variation of the Taylor picture task. We also use a virtual Water Maze, a joystick-operated simulation of the Morris Water Maze task, to test object-cued place memory. We hope to add several emotional memory tasks as well as a version of the memory game "Concentration" in the upcoming months. Currently, we are beginning to analyze data that may demonstrate a direct relationship between hippocampal activity and memory formation in humans. Further, we hope to examine the correlation between local field potentials (EEG) and single-unit activity.