Lucas C. Parra

Education

1985-1995: Ludwig-Maximilians-Universität, München, Germany
Ph.D. in Physics and Computer Science, 1996

Previous Affiliation

08/2003 - Current: City College of New York - Professor of Biomedical Engineering
03/2002 - 07/2002: Columbia University - Adjunct Assistant Professor of Biomedical Engineering
04/1997 - 07/2003: Sarnoff Corporation - Technology Leader, Adaptive Signal and Image Processing
04/1995 - 03/1997: Siemens Corporate Research - MTS, Imaging Department

Research Interests

The general area of interest is how temporal information of natural stimuli is encoded and processed by the brain. Experimental techniques focus on interpreting and modulating brain activity in humans non-invasively using electro-encephalography and trans-cranial electrical stimulation, in short: "reading" and "writing" the brain with electric fields. The work is often coupled with auditory and visual psychophysics and always incorporates computational or mathematical models.

In the News

The study on audiovisual speech recognition was featured in

• "Talking in person better", American Morning, CNN (March 4, 2009)

Our work on brain-reading technology has generated some interest in the popular media:

• Documentary: The Brain, History Channel (November 10, 2008)
• "Tapping the Computing Power of the Unconscious Brain" IEEE Spectrum Video (August 2008)
• "A Brainy Approach to Image Sorting", IEEE Spectrum (April 2008).
• "When the brain is a component of the computer", Politiken (Danish newspaper, July 2007).
• "Brain-Computer Interfaces: Where Human and Machine Meet", IEEE Computer Magazine (January 2007)
• "Subliminal Search", MIT Technology Review (July 2006)
• "Man and machine vision in perfect harmony", New Scientist, (July 2006)
• "This Is a Computer on Your Brain", Wired News (July 2006)
  

Teaching Experience

BME I5100 Biomedical Signal Processing (3 credits, graduate)
BME I5000 Medical Imaging and Image Processing (3 credit, graduate)
BME 22000 Biostatistics and Research Methods (3 credits, undergraduate)
BME 50500 Image and Signal Processing in Biomedicine (3 credits, undergraduate)

Current Research Topics (Collaborators)

Tinnitus modeling and psychophysics (Barak Pearlmutter, UNI; Glenis Long, CUNY)
EEG single-trial, real-time analysis (Paul Sajda, Columbia)
Role of field effects on spike time coherence (Marom Bikson, CCNY)
Models of spike time dependent plasticity (Tony Bell, Berkeley; Jeff Beck, Rochester University)
Psychophysics and modeling of audio-visual speech in noise (Wei Ji Ma, Rochester University)

Journal Publications

1. Kristen K. Maul, Henning U. Voss, Lucas C. Parra, Delanthi Salgado-Commissariat, Douglas Ballon, Ofer Tchernichovski, Santosh A. Helekar, "The development of stimulus-specific auditory responses requires song exposure in male but not female zebra finches," Developmental Neurobiology, in press, 2009.
2. Lucas C. Parra, Jeffrey M. Beck, Anthony J. Bell, "On the maximization of information flow between spiking neurons," Neural Computations, vol. 21, no. 11, November 2009.
3. Wei Ji Ma, Xiang Zhou, Lars A. Ross, John J. Foxe, Lucas C. Parra, " Lip-reading aids word recognition most in moderate noise: a Bayesian explanation using high-dimensional feature space," PLoS ONE, 4 (3) e4639, March 4, 2009. ( supplementary material, sample stimuli, press release)
4. Yuzhuo Su, Thomas Radman, Jake Vaynshteyn, Lucas C. Parra, Marom Bikson, "Effects of high-frequency stimulation on epileptiform activity in vitro: ON/OFF control paradigm," Epilepsia, vol. 49, no. 9, pp. 1586 - 1593, April 2008.
5. Yuzhuo Su, Sunitha Thakur, Karimi Sasan, Shuyan Du, Paul Sajda, Wei Huang, Lucas C. Parra, "Spectrum Separation Resolves Partial Volume Effect of MRSI as Demonstrated on Brain Tumor," NMR in Biomedicine, Vol. 21, No. 1, pp. 1030-1042, November 2008.
6. Lucas C. Parra, Christoforos Christoforou, Adam D. Gerson, Mads Dyrholm, An Luo, Mark Wagner, Marios G. Philiastides, Paul Sajda, "Spatio-temporal linear decoding of brain state: Application to performance augmentation in high-throughput tasks", IEEE Signal Processing Magazine, vol. 25, no. 1, pp. 95-115, January 2008.
7. Thomas Radman, Yuzhuo Su, Je Hi An, Lucas C. Parra, Marom Bikson, "Spike timing amplifies the effect of electric fields on neurons: implications for endogenous field-effects", Journal of Neuroscience, vol. 27, no. 11, pp. 3030-3036, March 2007.
8. Mads Dyrholm, Christoforos Christoforou, Lucas C. Parra, "Bilinear Discriminant Component Analysis", Journal of Machine Learning Research, vol. 8, pp. 1097-1111, 2007. Download matlab code and tutorial.
9. Lucas C. Parra, Barak A. Pearlmutter, "Illusory percepts from auditory adaptation", Journal of the Acoustical Society of America, vol. 121, no. 3, pp. 1632-1641, 2007.
   Download examples and matlab code.
10. Adam D. Gerson, Lucas C. Parra, Paul Sajda, "Cortically-coupled Computer Vision for Rapid Image Search", IEEE Transactions on Neural Systems & Rehabilitation Engineering, vol. 14, no. 2, pp. 174-179, June 2006.
    
11. Lucas C. Parra, "Steerable Frequency-Invariant Beamforming for Arbitrary Arrays", Journal of the Acoustical Society of America, 119 (6), pp. 3839-3847, June 2006.
    Download matlab code.
12. Clay D. Spence, Lucas C. Parra, Paul Sajda, "Varying Complexity in Tree-Structured Image Distribution Models", IEEE Transactions on Image Processing, vol. 5, no. 2, pp. 319-330, February 2006
13. Lucas C. Parra, Clay D. Spence, Adam D. Gerson, Paul Sajda, "Recipes for the Linear Analysis of EEG", Neuroimage, vol. 28, no. 2, pp. 326-341, November 2005.
    Download matlab code here.
14. Adam D. Gerson, Lucas C. Parra, Paul Sajda, "Cortical Origins of Response Time Variability During Rapid Discrimination of Visual Objects", Neuroimage, vol. 28, no. 2, pp. 342-353, November 2005.
    Download matlab code here.
15. Paul Sajda, Shuyan Du, Truman R. Brown, Radka Stoyanova, Dikoma C. Shungu, Xiangling Mao, Lucas C. Parra, "Nonnegative Matrix Factorization for Rapid Recovery of Constituent Spectra in Magnetic Resonance Chemical Shift Imaging of the Brain", IEEE Transaction on Medical Imaging, vol. 23, no. 12, December 2004
16. Lucas Parra, Chris Alvino, Akaysha Tang, Barak Pearlmutter, Nick Yeung, Allen Osman, Paul Sajda, ``Single-Trial Detection in EEG and MEG: Keeping it Linear'', Neurocomputing, vol. 52-54, June 2003, pp. 177-183, 2003.
17. Lucas Parra, Clay Spence, Adam Gerson and Paul Sajda, "Response Error Correction - A Demonstration of Improved Human-Machine Performance Using Real-Time EEG Monitoring", IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 11, no. 2, pp. 173 -177, June 2003.
18. Paul Sajda, Adam Gerson, Klaus-Robert Muller, Benjamin Blankertz, Lucas Parra, "A data analysis competition to evaluate machine learning algorithms for use in brain-computer interfaces", IEEE Transactions on Neural Systems and Rehabilitation Engineering, vol. 11, no. 2, pp. 184-185, June 2003.
19. Paul Sajda, Clay Spence, Lucas Parra, "A multi-scale probabilistic network model for detection, synthesis and compression in mammographic image analysis", Medical Image Analysis, vol. 7, no. 2 , June 2003, pp. 187-204, 2003.
20. Lucas Parra, Paul Sajda, "Blind Source Separation via Generalized Eigenvalue Decomposition", Journal of Machine Learning Research, vol. 4, pp. 1261-1269, 2003.
    See also Quickie Blind Source Separation.
21. Lucas Parra, Christopher Alvino, ``Geometric Source Separation: Merging convolutive source separation with geometric beamforming'', IEEE Transaction on Speech and Audio Processing, vol. 10, no. 6, pp. 352-362, Sept. 2002
22. Lucas Parra, Chris Alvino, Akaysha Tang, Barak Pearlmutter, Nick Yeung, Allen Osman, Paul Sajda, ``Linear Spatial Integration for Single-Trial Detection in Encephalography'', NeuroImage, vol. 17, no. 1, pp. 223-230, 2002
23. Lucas Parra, Clay Spence, "Convolutive blind source separation of non-stationary sources", IEEE Trans. on Speech and Audio Processing pp. 320-327, May 2000. US Patent US6167417.
    Listen to audio demonstrations.
    Download matlab code by Stefan Hamerling.
    Try your own BSS algorithm on real-room recordings.
24. Lucas Parra, "Reconstruction of cone-beam projections from Compton scattered data", IEEE Transactions on Nuclear Science, vol. 47., no. 4, part II, pp. 1543 -1550, August 2000.
25. Lucas Parra, Clay Spence, "On-line convolutive source separation of non-stationary signals", Journal of VLSI Signal Processing, vol. 26, no. 1/2, pp. 39-46, August 2000.
26. Lucas Parra, Harrison Barrett, "List-Mode Likelihood: EM Algorithm and Image Quality Estimation Demonstrated on 2-D PET", IEEE Transaction in Medical Imaging, Vol. 17, No. 2, pp. 228-235, April 1998.
27. Harrison Barrett, Timothy White, Lucas Parra, "List-Mode Likelihood", J. Opt. Soc. Am., 1997, 14 (11), pp. 2914-2923
28. Deco G., Parra L.: "Nonlinear Features Extraction by Unsupervised Redundancy Reduction with Stochastic Neural Networks", Neural Networks, 10, 683-691, 1997.
29. Parra L., Deco G., Miesbach S.: "Statistical independence and Novelty Detection with Information Preserving Nonlinear Maps", Neural Computation, 1996, Vol 8, 260-269.
30. Parra L., Deco G., Miesbach S.: "Redundancy Reduction with Information Preserving Nonlinear Maps", Network 1995, Vol. 1, No. 1, 61-72
31. Parra L., Deco G.: "Continuous Boltzmann Machine with Rotor Neurons", Neural Networks 1995, Vol. 8, No 3, 375-385
32. Deco G., Parra L.: "Unsupervised Learning for Boltzmann Machines", Network 1995, Vol. 6, 437-448.

Additional Information

Find here more publications, papers, etc.

Lucas C. Parra
Professor of Biomedical Engineering The City College of The City University of New York
Steinman Hall, T-403C
212.650.7211
212.650.6727
parra @ ccny.cuny.edu