Ethan A. Solomon

Brain stimulation

DLPFC stimulation suppresses high-frequency neural activity in the human sgACC
Building off prior studies examining the effects of TMS as measured by intracranial EEG, we tested the specific hypothesis that DLPFC stimulation causes changes in activity of the subgenual anterior cingulate cortex -- a key region involved in the regulation of mood. Using this technique, we showed that DLPFC stimulation transiently suppressess high-frequency activity in the sgACC, suggesting a possible mechanism by which TMS exerts its therapeutic effects in depression.
Brain Stimulation, Nov. 2025

TMS provokes target-dependent intracranial rhythms across human cortical and subcortical sites

In collaboration with colleagues at the University of Iowa, we examined intracranially-recorded responses to single-pulse TMS, teasing apart spectral responses in a wide array of brain regions. We found that spTMS tends to provoke brief but powerful low-frequency responses consistent with non-invasive measures of evoked potentials, but these responses were contingent on the area of stimulation and propagated to deep brain structures. 

Brain Stimulation, May 2024

Theta-burst stimulation entrains frequency-specific oscillatory responses

Theta-burst stimulation (TBS) is increasingly championed as a tool to modulate the activity of cognitively and clinically-relevant brain networks, but the mechanism by which it exerts effects on neural tissue is unknown. In a cohort of 20 neurosurgical patients, we examined the effects of intracranial TBS on mesoscale neural activity, finding that stimulation at a particular frequency can induce ongoing oscillations at that same frequency. 

Brain Stimulation, August 2021

Cognitive neuroscience

Theta oscillations in human memory

Nora Herweg and I review 25 years of work in human memory and electrophysiology. We offer a framework for understanding why theta oscillations are only variably associated with successful memory, explaining how experimental and analytic choices profoundly influence study findings. 

Trends in Cognitive Sciences, Mar. 2020

Hippocampal theta codes for distances in semantic and temporal spaces

Theta power in the human hippocampus encodes distances in semantic and temporal representational spaces, supporting the notion that the hippocampus generates domain-general "cognitive maps." 

PNAS, Nov. 2019

Dynamic theta networks in the human medial temporal lobe support episodic memory

During episodic memory encoding and retrieval, subregions of the medial temporal lobe -- and subfields of the hippocampus -- demonstrate changes in connectivity, with theta band connections particularly converging on the left entorhinal cortex. 

Current Biology, April 2019

Appointments

• Instructor, Stanford Dept. of Psychiatry (2025-current) 

• Postdoc/Resident, Keller Laboratory, Stanford (2022-2025)

• Postdoctoral researcher, Computational Memory Lab, UPenn (1/2019-7/2019)

• Graduate student, PI: Michael Kahana, UPenn (2015-2019)

• Technical Assistant, McGovern Institute, MIT (2012-2013)

• Research Assistant, PI: James DiCarlo, MIT (2009-2012)