People / Faculty
Emery N. Brown, M.D., Ph.D.
Professor of Computational Neuroscience and Health Sciences and Technology
Neural Signal Processing Algorithms
Recent technological and experimental advances in the capabilities to record signals from neural systems have led to an unprecedented increase in the types and volume of data collected in neuroscience experiments and hence, in the need for appropriate techniques to analyze them. Therefore, using combinations of likelihood, Bayesian, state-space, time-series and point process approaches, a primary focus of the research in my laboratory is the development of statistical methods and signal-processing algorithms for neuroscience data analysis.
We have used our methods to:
- characterize how hippocampal neurons represent spatial information in their ensemble firing patterns.
- analyze formation of spatial receptive fields in the hippocampus during learning of novel environments.
- relate changes in hippocampal neural activity to changes in performance during procedural learning.
- improve signal extraction from fMR imaging time-series.
- characterize the spiking properties of neurons in primary motor cortex.
- localize dynamically sources of neural activity in the brain from EEG and MEG recordings made during cognitive, motor and somatosensory tasks.
- measure the period of the circadian pacemaker (human biological clock) and its sensitivity to light.
- characterize the dynamics of human heart beats in physiological and pathological states.
- de-noise two photon in vivo imaging data.
Understanding General Anesthesia
General anesthesia is a neurophysiological state in which a patient is rendered unconscious, insensitive to pain, amnestic, and immobile, while being maintained physiologically stable. General anesthesia has been administered in the U.S. for more than 160 years and currently, more than 100,000 people receive anesthesia daily in this country for surgery alone. Still, the mechanism by which an anesthetic drug induces general anesthesia remains a medical mystery. My laboratory is using a systems neuroscience approach to study how the state of general anesthesia is induced and maintained. To do so, we are using fMRI, EEG, neurophysiological recordings, microdialysis methods and mathematical modeling in interdisciplinary collaborations with investigators in BCS, the MIT/Harvard Division of Health Science and Technology, Massachusetts General Hospital and Boston University. The long-term goal of this research is to establish a neurophysiological definition of anesthesia, safer, site-specific anesthetic drugs and to develop better neurophysiologically-based methods for measuring depth of anesthesia.
Chemali JJ, Van Dort CJ, Brown EN, Solt K. Active Emergence from Propofol General Anesthesiais Induced by Methylphenidate. Anesthesiology, 2012; In Press.
Ching S, Purdon PL, Vijayan S, Kopell N, and Brown EN. A neurophysiological-metabolic model for burst suppression. Proc Natl Acad Sci USA, 2012; In Press.
Solt K, Cotton JF, Cimenser A, Wong KFK, Chemali JJ, Brown EN. Methylphenidate induces emergence from general anesthesia, Anesthesiology. 2011, Oct., 115(4) : 791-803.
Brown EN, Purdon PL, Van Dort C. General anesthesia and altered states of arousal: a systems neuroscience analysis. Annual Review of Neuroscience, 2011, 34:601-628.
Cimenser A, Pierce ET, Salazar Gomez AF, Walsh J, Harrell PG, Tavares-Stoeckel CL, Habeeb K, Purdon PL, Brown EN. Tracking brain states under general anesthesia by using global coherence, Proceedings of the National Academy of Sciences, 2011, 108 (21): 8832-8837.
Brown EN, Lydic R, Schiff ND. General anesthesia, sleep and coma. New England Journal of Medicine, 2010, 363: 2638-2650.
Ching S, Cimenser A, Purdon PL, Brown EN,Kopell NJ. Thalamocortical model for a propofol-induced alpha rhythm associated with loss of consciousness. Proceedings of the National Academy of Sciences, 2010, 107(52): 22665-70.
Sarma SV, Cheng M, Williams Z, Hu R, Eskandar EE, Brown EN. Using point process models to compare neural spiking activity in the subthalamic nucleus of
Parkinson’s patients and a healthy primate. IEEE Transactions on Biomedical
Engineering, 2010, In Press.
Purdon PL, Pierce ET, Bonmassar G, Walsh J, Harrell PG, Kwo J, Deschler D,
Barlow M, Merhar RC, Lamus C, Mullaly CM, Sullivan M, Maginnis S, Skoniecki D,
Higgins HA, Brown EN.. Simultaneous electroencephalography and functional
magnetic resonance imaging of general anesthesia. Annals of the New York Academy of Science, 2009 Mar; 1157:61-70.
Smith AC, Shah SA, Hudson AE, Purpura KP, Victor JD, Brown EN, Schiff ND. A
Bayesian statistical analysis of behavioral facilitation associated with deep
brain stimulation. Journal of Neuroscience Methods, 2009 Oct 15; 183(2):267-76.
Prerau MJ, Smith AC, Eden UT, Kubota Y, Yanike M, Suzuki W, Graybiel AM, Brown EN. Characterizing learning by simultaneous analysis of continuous and binary measures of performance. Journal of Neurophysiology, 2009 Nov; 102(5):3060-72.