Srikantan Nagarajan

Research Interests

Multiscale and Multimodal imaging of dynamic cortical processing and cortical plasticity

Research Summary

The goals of my lab are to determine cortical network dynamics during complex information processing (eg. speech) and learning under normal, abnormal and disease conditions. We use a variety of multi-modal and multi-scale imaging methods for assaying cortical processing and plasticity such as magnetoencephalography (MEG), electroencephalography (EEG), functional magnetic resonance imaging (fMRI), electrocorticography (EcoG) and cortical electrophysiology using multi-electrode arrays. Various ongoing projects in the laboratory are:

1. Developing machine learning algorithms and software tools for multimodal cortical imaging

2. Developing machine learning algorithms for brain computer interfaces

3. Imaging auditory feedback processing during speech production

4. Imaging Cortical Plasticity due to learning

5. Determining the biophysical basis of functional imaging such as fMRI, DTI, MEG and EEG

6. Clinical studies of Brain Tumors, Epilepsy, Autism, Dyslexia, Learning Disabilities, Stroke, Parkinson's disease, Focal Hand Dystonia, Stutterring, Schizophrenia, Aging and Dementia

Selected Publications

1: Zumer JM, Attias HT, Sekihara K, Nagarajan SS.
Probabilistic algorithms for MEG/EEG source reconstruction using temporal basis
functions learned from data.
Neuroimage. 2008 Feb 20. [Epub ahead of print]
PMID: 18455439 [PubMed - as supplied by publisher]

2: Dalal SS, Guggisberg AG, Edwards E, Sekihara K, Findlay AM, Canolty RT, Berger
MS, Knight RT, Barbaro NM, Kirsch HE, Nagarajan SS.
Five-dimensional neuroimaging: Localization of the time-frequency dynamics of
cortical activity.
Neuroimage. 2008 May 1;40(4):1686-700. Epub 2008 Jan 31.
PMID: 18356081 [PubMed - in process]

3: Sekihara K, Hild KE, Dalal SS, Nagarajan SS.
Performance of prewhitening beamforming in MEG dual experimental conditions.
IEEE Trans Biomed Eng. 2008 Mar;55(3):1112-21.
PMID: 18334403 [PubMed - indexed for MEDLINE]

4: Hild KE 2nd, Attias HT, Nagarajan SS.
An expectation-maximization method for spatio-temporal blind source separation
using an AR-MOG source model.
IEEE Trans Neural Netw. 2008 Mar;19(3):508-19.
PMID: 18334368 [PubMed - in process]

5: Guggisberg AG, Kirsch HE, Mantle MM, Barbaro NM, Nagarajan SS.
Fast oscillations associated with interictal spikes localize the epileptogenic
zone in patients with partial epilepsy.
Neuroimage. 2008 Jan 15;39(2):661-8. Epub 2007 Sep 29.
PMID: 17977022 [PubMed - indexed for MEDLINE]

6: Guggisberg AG, Honma SM, Findlay AM, Dalal SS, Kirsch HE, Berger MS, Nagarajan
SS.
Mapping functional connectivity in patients with brain lesions.
Ann Neurol. 2008 Feb;63(2):193-203.
PMID: 17894381 [PubMed - indexed for MEDLINE]