Research

Ketamine for treatment resistant depression

Ketamine produces a rapid antidepressant response in over 50% of adults with treatment-resistant depression but benefits usually fade within a week. We explored a prolonged ketamine infusion. We found that a 96-hr infusion produces marked reduction in depression that persisted for months. Additionally, pathological hyperconnectivity in areas critical to mood and emotion (limbic system, subgenual cingulate, DMN) were reversed for weeks after infusion.

neurobiological mechanisms of Psilocybin

In recent years, studies using psychedelics to treat a range of psychiatric conditions have shown astounding results. This has led to a resurgence of interest in these drugs. Psilocybin has been granted breakthrough therapy designation by the FDA. My research, with Dr. Ginger Nicol and the Healthy Minds Lab, explores the neurobiological adaptations associated with therapeutic effects of this fascinating class of drugs.


Improving functional brain imaging methods

Statistical Improvements in Functional Magnetic Resonance Imaging Analyses Produced by Censoring High-Motion Data Points Joshua S. Siegel,1* Jonathan D. Power,1 Joseph W. Dubis,1 Alecia C. Vogel,1 Jessica A. Church,1 Bradley L. Schlaggar,1,2,3,4 and Steven E. Petersen1
The effects of hemodynamic lag on functional connectivity and behavior after stroke Joshua S Siegel1, Abraham Z Snyder1,2, Lenny Ramsey1, Gordon L Shulman1 and Maurizio Corbetta1,2,3

Through my PhD and residency, I have remained committed to developing rigorous methods for measuring brain function using functional MRI that carefully measure and remove the influence of physiological confounds such as head motion, arousal, CO2, hemodynamics, and neurovascular coupling.

understanding stroke in the connected human brain

Disruptions of network connectivity predict impairment in multiple behavioral domains after stroke Joshua Sarfaty Siegela,1, Lenny E. Ramseya, Abraham Z. Snyderb, Nicholas V. Metcalfa, Ravi V. Chackoc, Kilian Weinbergerd,e, Antonello Baldassarrea,f, Carl D. Hackerc, Gordon L. Shulmana, and Maurizio Corbetta
Network view comparing connectivity changes related to different deficits following stroke

My PhD research focused on using MRI to characterize the effects of stroke on distributed brain systems. We followed a large cohort (N=132) over a year after stroke, collecting structural and functional imaging and assessing deficit and recovery across a broad range of behavioral domain. This dataset taught us that some abilities are localized in the brain (vision, movement) while others are more dependent on broadly distributed network function (memory, language, attention).