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Event ANT Neuromeeting 2026 - Philadelphia starts on Apr 15, 2026, 3:30:00 AM (US/Eastern)
Striatal Stimulation Recruits Bilateral Language Networks and Enhances Neural Manifold Discriminability During Swahili Learning
Neuroimaging Across Disciplines
4/15/26, 10:00 AM - 4/15/26, 10:35 AM (US/Eastern) (35 minutes)
Striatal Stimulation Recruits Bilateral Language Networks and Enhances Neural Manifold Discriminability During Swahili Learning
Nathaniel J. Killian, PhD
Assistant Professor at Montefiore Einstein Neurosurgery
Nathaniel J. Killian, PhD
Assistant Professor at Montefiore Einstein Neurosurgery
Nathan Killian is an Assistant Professor of Neurological Surgery at Albert Einstein College of Medicine, Director of the Killian Lab for Vision and Memory Research, and co-founder and Chief Scientific & Technical Officer of Neuradaptive Inc. His research focuses on human intracranial electrophysiology, closed-loop control of neural activity, and translational neural interfaces. He received his Ph.D. in Bioengineering from Georgia Institute of Technology and completed postdoctoral training at Harvard Medical School - Massachusetts General Hospital. His work spans adaptive deep brain stimulation (DBS) for learning and memory enhancement, thalamic visual prosthetics, and digital health technology. His laboratory collaborates with the Montefiore Epilepsy Surgery team and uses stereoelectroencephalography (SEEG) in epilepsy patients to investigate the neural circuit mechanisms of learning, memory, and visual perception, with the goal of developing stimulation-based therapies for post-stroke aphasia, memory disorders, and irreversible blindness. His prior work includes the discovery of spatial view grid cells and saccade direction cells in the entorhinal cortex and the first demonstration of letter recognition through a chronically implanted prototype thalamic visual prosthesis.
The use of language is essential for virtually all social interactions, yet the neurophysiological mechanisms underpinning language learning are poorly understood, limiting our ability to treat disorders such as aphasia, which affects over 2 million people in the US. Beyond speech therapy, there are no accepted pharmacological or neuromodulatory treatments for chronic aphasia. Past work has shown that high-frequency stimulation of nucleus accumbens (NAc) during stimulus presentation, coupled with caudate (Cd) stimulation following correct responses, boosts associative learning rates. Since language is acquired primarily through associative learning, we propose that precisely timed stimulation of these striatal hubs can causally enhance language learning.

Five epilepsy patients undergoing stereotactic electroencephalography (SEEG) monitoring performed a four-alternative forced-choice Swahili word learning task with bilateral NAc+Cd stimulation (8-16 words per subject learned over 240-330 trials). Stimulation accelerated learning and improved learning efficiency measured in bits/trial (mean efficiency ratio 2.3x across subjects). Using matched-channel laterality analysis, we found that right subcortical-cortical ensemble activity represented word identity significantly better with stimulation. Stimulation resulted in a right hemisphere decoding gain of up to 58% after the learning criterion trial (p<0.05, cluster-based permutation test). Spectral analyses revealed that this was a broadband and dynamic effect characterized by traveling waves that traverse distinct neural manifolds. Single-trial local field potentials projected into a shared principal component space showed that stimulated words occupied distinct, well-separated trajectories, whereas unstimulated words clustered in a narrower manifold. Pairwise trajectory distances were up to 2.7x larger for stimulated words, demonstrating that stimulation created word-specific neural signatures rather than a uniform enhancement in signal magnitude. Taken together, these results support precise NAc+Cd stimulation for circuit-based language rehabilitation.