Leif
H. Finkel, MD, PhD
leif@neuroengineering.upenn.edu
Professor of Bioengineering
Member of the Institute for Neurological Sciences
Member of the Institute for Medicine and Engineering
Member of the Institute for Research in Cognitive Science
A
primary aim of the lab has been the modeling of perceptual computations
in early visual cortex. We are interested in learning how the architecture
and physiological properties of cells in primary visual cortex might
be able to account for a number of the Gestalt laws of perception as
well as numerous other psychophysical findings.
A relatively new direction for our research has been modeling mammalian
brain function using biologically-realistic, highly-detailed models
of individual neurons and their assemblies.These models can provide
critical insights into biological function and pathology that abstracted
"neural network" models often cannot provide. One particular project
of ours is focusing on the design of a functional, cellular-level model
of the hippocampus. It is our intention to use this model in researching
a number of diseases that profoundly affect the hippocampus and related
structures, most notably Alzheimer's disease and traumatic brain injury.
We are also pursuing the development of object-recognition systems that
utilize hierarchical feature-based techniques. Work to this point includes
examples in face recognition and autonomous navigation in virtual worlds.
| Leif Finkel | Professor | [ e-mail ] |
| Maciej Lazarewicz | Research Associate | [ e-mail ][ web ] |
| John A. Wolf | Post-Doctoral Fellow | [ e-mail ][ web ] |
| Jason Moyer | Graduate student | [ e-mail ][ web ] |
| Robert Wilson | Graduate student | [ e-mail ] |
| Sandy Das | Graduate student | [ e-mail ][ web ] |
| Thomas Murphy | Graduate student | [ e-mail ] |
| Shabbar Danish | Research fellow | [ e-mail ] |
Cortical Architecture and Visual Perception
Over the last several years a primary aim of the lab has been the modeling
of perceptual computations in early visual cortex. The traditional view
of early visual cortex as a static bank of filters has become outdated
as we learn more and more about the characteristics of neurons when they
are interacting with other neurons. Particularly interesting are the effects
mediated by the long-range horizontal connections found in the superficial
layers of visual cortex. We are interested in learning how the architecture
and physiological properties of cells in primary visual cortex might be
able to account for a number of the Gestalt laws of perception as well
as numerous other psychophysical findings.
Hippocampal Function and Disease
A relatively new direction for our research has been modeling mammalian
brain function using biologically-realistic, highly-detailed models of
individual neurons and their assemblies. When subject to the constraints
of known neuroanatomy, neurophysiology, and the biophysics of biological
membranes, ion channels, receptors, and neuromodulatory substances, these
models can provide critical insights into biological function and pathology
that abstracted "neural network" models often cannot provide.
One particular project of ours is focusing on the design of a functional,
cellular-level model of the hippocampus, a region of the medial temporal
lobe known to be criticial for our processing of novel information prior
to its consolidation in memory. In addition to investigating how actual
neurons can process information and memories, it is our intention to use
this model in researching a number of diseases that profoundly affect
the hippocampus and related structures, most notably Alzheimer's disease
and traumatic brain injury.
One application of neural networks that we are currently pursuing is the solution of the "cocktail party problem," so-named for our ability to focus our attention on one conversation of many that would be occuring concurrently at a hypothetical cocktail party. Also known as "blind signal separation," this problem of separating a mixture of signals, detected by a set of sensors, into their original source signals is performed extremely well by the human brain, and over the years attempts have been made to capture this function using assemblies of abstracted neurons.
A popular current approach employs an algorithm that minimizes the mutual information between outputs of the network. We hope to develop improvements upon this network model and to incorporate additional information arising from the spatial separations of the sensors.
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Nucleus Accumbens | |
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Wolf JA, Moyer JT, Lazarewicz MT, Contreras D, Benoit-Marand M, O'Donnell P, Finkel LH (2005) NMDA/AMPA ratio impacts state transitions and entrainment to oscillations in a computational model of the nucleus accumbens medium spiny projection neuron. J Neurosci 25:9080-95.
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Wolf JA, Moyer JT, Finkel LH. (2005) The role of NMDA currents in state transitions of the nucleus accumbens medium spiny neuron. Neurocomputing 65-66:565-70.
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Wolf JA, Finkel, LH, A Computational Model of the Nucleus Accumbens: Network Properties and their Functional Implications. EMBS, 2003.
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Wolf, JA, Schroeder, LF, Finkel, LH, Computational Modeling of Medium Spiny Projection Neurons in Nucleus Accumbens: Toward the Cellular Mechanisms of Afferent Stream Integration, Proceedings of the IEEE, Volume 89, Issue 7, July 2001, pages 1083-1092.
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Hippocampus | |
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Lazarewicz, MT, Ang, C-W, Carlson, GC, Coulter, DA, Finkel, LH, Analysis of NMDA-Dependent Voltage Bistability in Thin Dendritic Compartments, Neurocomputing, (in press)
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Menschik ED, Finkel LH: Cholinergic neuromodulation of an anatomically reconstructed hippocampal CA3 pyramidal cell. Neurocomputing, 32-33:197-205, 2000
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Menschik ED, Finkel LH: Cholinergic neuromodulation and Alzheimer's disease: from single cells to network simulations. Progress in Brain Research, 121:19-45.
[ Introduction ][ Full text ] | |
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Menschik ED, Yen S-C, Finkel LH: Model- and scale-independent performance of a hippocampal CA3 network architecture. Neurocomputing, 26-27(1-3):443-453, 1999
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Menschik ED, Finkel LH: Neuromodulatory control of hippocampal function: Towards a model of Alzheimer's disease. Artificial Intelligence in Medicine, 13(1-2):99-121, May 1998.
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Menschik ED, Yen SC, Finkel LH: Attractor Dynamics in Realistic Hippocampal Networks. Computational Neuroscience: Trends in Research, 1998, New York: Plenum Press, pp. 465-470.
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Visual Cortex | |
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Das SR, Lazarewicz, MT, Wilson, RC, Finkel, LH, Motion Features for Gait Recognition and Prediction, (in revision).
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Contreras, D and Finkel, LH, Mechanisms of Cortical Computation. In: Neural Engineering, Bin He, ed., Kluwer, New York, 2005.
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Das SR, Wilson RC, Lazarewicz MT, Finkel LH, 7th IEEE International Conference on Automatic Face and Gesture Recognition (in press).
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Wilson RC, Das SR, Finkel LH, Motion as Shape: A Novel Method for the Recognition and Prediction of Biological Motion, submitted to British Machine Vision Conference, 2006.
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Lazarewicz, MT, Das, SR, Finkel, LH: Recognition of Temporal Event Sequences by a Network of Cortical Neurons, Neurocomputing, 2005, 65
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Das, SR, Lazarewicz, MT, Finkel, LH, Principal Component Analysis of Temporal and Spatial Information for Human Gait Recognition, Proceedings of the 26th Annual International Conference of IEEE Engineering in Medicine and Biology Society(EMBS), Sep 1-5, 2004, San Francisco, CA.
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Grossberg, S, Finkel, LH and Fields, D eds., “Vision and Brain” Elsevier, Amsterdam, 2004.
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Das, S and LH Finkel, Cortical integration of bottom-up, top-down and horizontal information in biological motion recognition, Proceedings of the 1st Intl IEEE EMBS Conference on Neural Engineering, Capri Island, Italy, 2003.
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Murphy, TM, Matlin M, and Finkel, LH (2003) Curvature covariation as a factor in perceptual salience. Proc. of the 1st International IEEE EMBS Conf. on Neural Engineering, Capri., pp. 16-19.
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Nafziger JS, Finkel LH: A stimulus density-dependent normalization mechanism for modulating the range of contour integration. Neurocomputing, (in press)
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Nafziger JS, Yen S-C, Finkel LH: Psychophysical Determination of the Spatial Connectivity Function in a Model of Contour Salience. Neurocomputing, 26-27(1-3):823-830, 1999
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Yen S-C, Menschik ED, Finkel LH: Perceptual grouping in striate cortical networks mediated by synchronization and desynchronization. Neurocomputing, 26-27(1-3):609-616, 1999
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Yen SC, Finkel LH: Extraction of Perceptually Salient Contours by Striate Cortical Networks. Vision Research 38(5):719-741, (1998)
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Yen SC, Menschik ED, Finkel LH: Cortical Synchronization and Perceptual Salience. Computational Neuroscience: Trends in Research, 1998, New York: Plenum Press, pp. 125-130.
[ Abstract ][ Full text ] | |
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Sakai K, Finkel LH: Spatial-frequency analysis in the perception of perspective depth. Network: Computation in Neural Systems, 8(3):335-352, (1997).
[ Abstract ][ Full text ] | |
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Yen SC, Finkel LH: Identification of Salient Contours in Cluttered images. Computer Vision and Pattern Recognition, pp. 273-279, IEEE Computer Society Press (1997)
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Yen SC, Finkel, LH: Cortical Synchronization Mechanism for "Pop-Out" of Salient Image Contours. Computational Neuroscience: Trends in Research 1997, pp. 553-560, (1997).
[ Abstract ][ Full text ] | |
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Yen SC, Finkel, LH: Salient Contour Extraction by Temporal Binding in a Cortically-Based Network. Advances in Neural Information Processing Systems 10, pp. 915-921, (1997).
[ Abstract ][ Full text ] | |
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Courtney SM, Finkel LH, Buchsbaum G: A Multi-Stage neural network for Color Constancy and Color Induction, IEEE Transactions on Neural Networks, 6:972-985 (1995)
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Courtney SM, Finkel LH, Buchsbaum G: Network Simulations of Retinal and Cortical Contributions to Color Constancy Vision Research 35:413-434 (1995)
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Sakai K, Finkel LH: Characterization of Spatial Frequency Cues in the Perception of Shape-from-Texture. Journal of the Optical Society of America, A 12:1208-1224, 1995.
[ Abstract ][ Full text ] | |
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Sajda P, Finkel LH: Intermediate-Level Visual Representations and the Construction of Surface Perception, Journal of Cognitive Neuroscience. 7:267-291, 1995.
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Finkel LH, Sajda P: Constructing visual perception. American Scientist 82:224-37, 1994
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Sakai K, Finkel LH: A Cortical Mechanism Underlying the Perception of Shape- from-Texture. in The Neurobiology of Computation, pp. 115-120, F. Eeckman and J. Bower, eds., Kluwer, 1994.
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Yen SC, Sajda P, Finkel, LH: Face Recognition by PDP and Radial Basis Function Networks: Comparisons and Insights. in The Neurobiology of Computation, pp. 433-438, F. Eeckman and J. Bower, eds., Kluwer, 1994.
[ Abstract ][ Full text ] | |
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Translational Neuroengineering | |
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Finkel LH Neuroengineering Models of Brain Disease, Annual Reviews of Biomedical Engineering, 2: 577-606 (2000).
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Moyer JT, Danish SF, Keating JG, Finkel LH, Baltuch GH, Jaggi JL. Implementation of dual simultaneous microelectrode recording systems during deep brain stimulation for Parkinson’s disease. Submitted.
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Moyer JT, Danish SF, Finkel LH. Deep brain stimulation: anatomical, physiological, and computational mechanisms. In: Deep brain stimulation for Parkinson’s disease: a comprehensive text (Baltuch GH, Stern D, ed), in press.
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Danish SF, Moyer JT, Jaggi JL. Microelectrode recordings. In: Deep brain stimulation for Parkinson’s disease: a comprehensive text (Baltuch GH, Stern D, ed), in press.
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Danish SF, Jaggi JL, Moyer JT, Finkel LH, Baltuch GH. Anatomic variability in the red nucleus and subthalamic nucleus relationship in Parkinson's disease: implications for targeting. Stereotact Funct Neurosurgery, submitted.
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Danish SF, Jaggi JL, Moyer JT, Finkel L, Baltuch GH (2006) Conventional MRI is inadequate to delineate the relationship between the red nucleus and subthalamic nucleus in Parkinson’s disease. Stereotact Funct Neurosurg 84: 12-18.
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Geerts H, Finkel L., Carr R, Spiros A, Nicotinic receptor modulation: advantages for successful Alzheimer's disease therapy. J Neural Transm Suppl. 62:203-16, 2002.
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Geerts H., Dani J., Spiros, A., Finkel, L., Lazarewicz, M., R. Carr, R., The increase of dopamine by galantamine explains its proven clinical benefits on non-cognitive scales, European Neuropsychopharmacology 12: S380-S380 Suppl., 2002
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Lazarewicz M, Spiros A, Finkel L, et al., Understanding the dual mode of action of galantamine using a virtual synaptic cleft, Neurobiology of Aging 23 (1): 447 Suppl. 1, 2002
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Geerts H, Lazarewicz M, Spiros A, et al. Galantamine benefits in Alzheimer's disease are related to increases in dopamine output, Schizophrenia Research 60 (1): 135.
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Miscellaneous Neuroscience | |
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Finkel LH, Yen S-C, Menschik ED: Synchronization: The Computational Currency of Cognition. ICANN 98, Proceedings of the 8th International Conference on Artificial Neural Networks Skövde, Sweden, 2-4 September 1998. Niklasson L, Boden M, Ziemke T (eds.). New York: Springer-Verlag, 1998.
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Finkel LH, Pearson JC, Edelman GM: Models of Topographic Map Organization, in Pattern Formation in the Physical and Biological Sciences, H. F. Nijhout, Lynn Nadel, Daniel Stein, and F. Nijhout, eds., Reading, MA:Addison-Wesley, 1997.
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Kim DH and Finkel LH (2003) Hyperspectral image processing using locally linear embedding. Proc. of the 1st International IEEE EMBS Conf. on Neural Engineering, Capri., pp. 316-319.
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Crystal H, Finkel LH: Computational Approaches to Neurological Disease. In Neural Modeling of Brain and Cognitive Disorders. Reggia JA, Ruppin E, Sloan Berndt R, eds., River Edge, NJ: World Scientific Publishing, 1996, pp. 251-271.
[ Abstract ][ Full text ] | |
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Reeke GN, Finkel LH, Edelman GM: Selective Recognition Automata, in An Introduction to Neural and Electronic Networks, 2nd edition, S.F. Zornetzer, J.L. Davis, and C. Lau, and T. McKenna, eds., New York:Academic Press, 1995, pp. 205-228
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Neural Simulation | |
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Sakai K, Sajda P, Yen SC, Finkel LH: Coarse-grain Parallel Computing for Very Large Scale Neural Simulations in the NEXUS Simulation Environment. Computers in Biology and Medicine, 27(4):257-266, (1997).
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Sajda P, Sakai K, Yen SC, Finkel, LH: Nexus: A Neural Simulator for Integrating Top-Down and Bottom-Up Modeling. in Neural Network Simulation Environments, pp. 29-45, J. Skrzypek, ed., Kluwer, 1994.
[ Abstract ][ Full text ] |
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Das, S.R., Lazarewicz, M.T., Wilson, R.C., Finkel, L.H., Sensitivity to motion features in upright and inverted point-light displays, VSS 2006, Sarasota, FL.
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Lazarewicz MT, Ang C-W, Carlson GC, Coulter DA, Finkel LH, Local Circuit Activity Shapes Temporoammonic Inputs To The Distal Apical Tuft Of Hippocampal CA1 Pyramidal Neuron: A Computer Simulation Study, Society For Neuroscience 2005
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Moyer JT, Wolf JA, Contreras D, Finkel LH (2005) Dopaminergic modulation and afferent input integration in a computational model of the nucleus accumbens medium spiny neuron. In: Society for Neuroscience. Washington, DC.
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Lazarewicz MT, Das SR, Finkel LH, Recognition of Temporal Event Sequences by a Network of Cortical Neurons, Computational Neuroscience (CNS) 2004, Baltimore, July 18-22, 2004.
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Cranstoun SD, Carlson GC, Litt B, Finkel LH, Coulter DA: Modeling activation of extrasynaptic GABAA receptors by synaptic spillover. Society for Neuroscience Abstracts 34. The 34th Annual Meeting of the Society for Neuroscience, San Diego, CA, October 23-27, 2004.
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Lazarewicz MT, Das SR, Finkel LH, Rapid gait recognition utilizes coarse features, Society For Neuroscience 2004, San Diego
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Wolf JA, Eleey CE, Finkel LH, Contreras D (2004) Afferent Information Integration in the Nucleus Accumbens in the Awake Rat. In: Society for Neuroscience. San Diego.
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Wolf JA, Moyer JT, Finkel LH. (2004) The role of NMDA currents in state transitions of the medium spiny neuron in a network model of the nucleus accumbens. In: Computational Neuroscience. Baltimore.
[ Abstract ][ Tarred JPG ] | |
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Moyer JT, Wolf JA, Benoit-Marand M, O’Donnell P, Finkel LH. (2004) A computational model of the nucleus accumbens: NMDA:AMPA ratio affects state transitions. In: Society for Neuroscience. San Diego.
[ Abstract ][ Tarred JPG ] | |
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Das SR, Lazarewicz, MT, Finkel LH, Principal Component Analysis of Temporal and Spatial Information for Human Gait Recognition, IEEE, EMB 2004, San Francisco
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Lazarewicz MT, Das, SR, Finkel, LH, Event Signatures in Biological Motion Detection. 591.22, Society For Neuroscience 2003 Annual Meeting, New Orleans, LA.
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Das SR, Lazarewicz MT, Finkel LH, Insights into Biological Motion Recognition from Principal Component Analysis of Human Gait, BMES 2004, Philadelphia.
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Cranstoun SD, Lazarewicz MT, Litt B, Finkel LH, Parameter Searching In Neuronal Models With Multi-Objective, Genetic Algorithms, BMES 2004, Philadelphia.
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Moyer JT, Wolf JA, Finkel LH, Computational model of the nucleus accumbens medium spiny neuron, BMES 2004, Philadelphia.
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Murphy TM, Finkel LH, Object Recognition by a Network of V4-like Cells, BMES 2004, Philadelphia.
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| Mark Albert, PhD |
malbert@wjh.harvard.edu Lecturer School of Psychology University of Southhampton UK |
| Susan Courtney, PhD |
courtney@jhu.edu Assistant Professor Department of Psychology Johns Hopkins University 132 Ames Hall, 3400 North Charles Street Baltimore, MD 21218-2686 410.516.8894 (V) / 410.516.4478 (F) |
| Ben Joseph, MS |
bjoseph@mit.edu Massachusetts Institute of Technology Department of Mathematics Cambridge, MA 02139 |
| Mark Matlin, PhD |
mmatlin@brynmawr.edu Senior Lecturer Department of Physics Bryn Mawr College Telephone: (610) 526 - 5355 Fax: (610) 526 - 7469 |
| Elliot Menschik, MD PhD |
CEO, HX Technologies Philadelphia, PA Phone: 215 923 4984 Fax: 215 689 3891 |
| Sean Murphy, PhD |
seandmurphy@yahoo.com Celera Genomics Corporation 45 West Gude Drive Rockville, MD 20850 240-453-3000 |
| John Nafziger |
Technical staff Siemens Corporate Research Princeton, NJ |
| Paul Sajda, PhD |
ps629@columbia.edu Associate Professor Department of Biomedical Engineering Columbia University New York, NY |
| Ko Sakai, PhD |
sakai@is.tsukuba.ac.jp Associate Professor University of Tsukuba Institute of Information Sciences and Electronics 1-1-1 Tennodai, Tsukuba Ibaraki 305-8573, Japan 0298-53-5206 (Fax) |
| Shih-Cheng Yen, PhD |
syen@neuroengineering.upenn.edu Assistant Professor Department of Electrical and Computer Engineering National University of Singapore (T) +65.6516.2118 (F) +65.6779.1103 |
Page last modified 26 May, 2006
