Herz Research
1015 Walnut Street
Curtis Building, Suite 709
Philadelphia, PA 19107
Memories serve as the building blocks of our mental life; our sense of self derives from our ability to remember our past. Memory deterioration, resulting from neurological disorders or injuries, can profoundly impact our cognitive and social functioning. Conversely, memories can become excessively intrusive, detrimentally influencing our mood and cognitive abilities. Our lab investigates the neuronal mechanisms underlying human memory, including memory for emotional events, with the goal of developing therapeutic interventions for neurologic and psychiatric disorders afflicted with memory impairments.
Research Projects
Elucidating Oscillatory Mechanisms of Memory Functions
Research in both humans and animals has identified theta oscillations as a crucial component of episodic memory. These oscillations are believed to support encoding and retrieval by coordinating the formation of associations between sequential inputs, integrating diverse environmental features into a unified, contextualized memory. By delivering direct brain stimulation while neurosurgical patients participate in memory tasks, we aim to determine the causal role of these oscillations in memory function. We are interested in developing individualized memory modulation strategies that rely on the patients’ brain structure and function to improve stimulation effects on memory.
Spatial-Verbal Memory task. Right: Birdseye view of the virtual environment overlaid with the location of the delivered items (inset shows the environment from the player’s viewpoint). Left: Intracranial theta-burst stimulation is applied during encoding and retrieval.
Unwanted Memories of Traumatic Life Events
Research of memory has largely focused on voluntary and deliberate retrieval of past experiences. However, memory recall is often involuntary, triggered by specific cues without intention or effort, particularly following emotional events. This involuntary retrieval is a hallmark symptom of post-traumatic stress disorder (PTSD). Our lab investigates the neuronal mechanisms underlying involuntary retrievals and the factors that predispose individuals for intrusion development. By using direct brain recording and stimulation in epilepsy patients, we aim to elucidate the neural networks involved in these intrusions and develop therapeutic interventions for intrusion alleviation.
Hippocampal biomarkers of false recall. Left: stereo-electroencephalography electrode implanted in the hippocampus. Right: Correct recalls exhibit increased low-theta, decreased 6-18 Hz, and increased gamma (>44 Hz) activity relative to false recalls.
Translational Studies of Neurological Disorders Afflicted with Memory Impairments
Memory impairment is a significant concern for patients undergoing neurosurgery. Neurologists have long employed direct electrical stimulation of the brain to map eloquent cortical functions, such as language, to prevent related functional impairment following brain resection. Despite the major influence of memory functions on patients' well-being and daily lives, there are currently no equivalent well-established methods for memory function. Our lab aims to develop a reliable tool to predict memory outcomes following neurosurgery using direct brain stimulation of mesial temporal lobe areas and innovative memory assessment techniques. This research could greatly improve neurosurgical planning and enhance the quality of life for patients.
Illustration of memory mapping procedure.