Fritz Sommer

Friedrich T. Sommer, Ph.D.
University of California, Berkeley
Redwood Center for Theoretical Neuroscience - HWNI
3210F Tolman Hall MC 3192
Berkeley, CA 94720
phone (510) 642-7251
fax (510) 642-7206
email F $ 0 M M E R (a) B E R K E L E Y * E D U (please retype)

Associate Adjunct Professor, Redwood Center for Theoretical Neuroscience & Helen Wills Neuroscience Institute, University of California, Berkeley
Faculty member (Hochschuldozent), Department of Computer Science, University of Ulm

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Research Interests

Many impressive capabilities of the brain are not yet understood, for example, abilities in perception to rapidly analyze cluttered visual scenes, spoken language, morse code or the virtually unlimited capacity of our long-term memory. My lab focusses on the question how neurons and networks in the brain collaborate to produce perception, memory and ultimately cognition. To study this question we use computational models of the brain and advanced techniques of data analysis. For a full list of the research publications, see the cv.

I am also interested in how we can develop data sharing activities in neuroscience, allowing to exploit experimental data from many diverse angles. In other fields, such as genomics and linguistics, data sharing has became ubiquitous and highly successful, in neuroscience we are still quite at the beginning. My lab is building the core facilities for a new data sharing initiative in Neuroscience CRCNS.org

Recent Publications

Manuscripts in preparation/submitted (2008)

A. Knoblauch, G. Palm, F. T. Sommer: Unbiased performance measures for associative memory reveal a functional role of structural plasticity.

K. Koepsell, X. Wang, Y. Wei, V. Vaingankar, J. A. Hirsch, F. T. Sommer: Dynamical coding opens a novel channel for visual information to reach cortex.

S. Chen, F. T. Sommer, L. M. Frank: Neurogenesis and transient memory storage in the dentate gyrus.

Posters/Talks at upcoming conferences (2007)

A. Knoblauch, F. T. Sommer, M.-O. Gewaltig, A. Kupper, U. Koerner, E. Koerner: A model for structural plasticity in neocortical associative networks trained by the hippocampus. CNS 2007, Toronto.

K. Koepsell, X. Wang, Yichun Wei, Q. Wang, V. Vaingankar, J. Hirsch, F. T. Sommer: Retinal oscillations carry visual information to cortex. Meeting of the Biomedical Engineering Society 2007, Los Angeles.

M. Rehn, D. K. Warland, F. T. Sommer: A minimal computational model that captures the shape diversity of V1 receptive fields. Meeting of the Society for Neuroscience 2007, San Diego.

Journal articles, in the press/recently published

J. L. Teeters, K. D. Harris, K. J. Millman, B. A. Olshausen, F. T. Sommer: Data sharing for computational neuroscience. Neuroinformatics (2008) pdf

X. Wang, Y. Wei, V. Vaingankar, Q. Wang, K. Koepsell, F. T. Sommer, J. A. Hirsch: Feedforward excitation and inhibition evoke dual modes of firing in the cat’s visual thalamus during naturalistic viewing. Neuron 55 (2007) 465-478. See also the preview about this paper: P. Reinagel: The inner life of bursts. Neuron 55 (2007) 339-341

F. T. Sommer: Bunte Theorien für graue Zellen. Gehirn und Geist, Juni (2007) 70-76

M. Rehn, F. T. Sommer: A network that uses few active neurones to code visual input predicts the diverse shapes of cortical receptive fields. J. Comp. Neurosci. 22 (2) 135-146 (2007). pdf Earlier online prepublication SpringerLink DOI 10.1007/s10827-006-003-9 (2006)

M. Rehn, F. T. Sommer: Storing and restoring visual input with collaborative rank coding and associative memory. Neurocomputing 69 (10-12) (2006) 1219-1223 pdf

F. T. Sommer, P. Kanerva: Can neural models of cognition benefit from the advantages of connectionism? Behavoral and Brain Sciences 29 (1) 86-87 (2006) pdf

F. T. Sommer, T. Wennekers: Synfire chains with conductance-based neurons: internal timing and coordination with timed input. Neurocomputing 65-66 (2005) 449 - 454 pdf

D. George, F. T. Sommer: Computing with inter-spike inverval codes in networks of integrate and fire neurons. Neurocomputing 65-66 (2005) 414 - 420 pdf

L. M. Martinez, Q. Wang, R. C. Reid, C. Pillai, J.-M. Alonso, F. T. Sommer, J. A. Hirsch: Receptive field structure varies with layer in the primary visual cortex. Nature Neuroscience 8 (12) (2005) 372 - 379 pdf

A. Knoblauch, F. T. Sommer: Spike-timing dependent plasticity can form "zero-lag" links for cortical oscillations. Neurocomputing 52-54 (2004) 301 - 306 pdf

M. Rehn, F. T. Sommer: A network for the rapid formation of binary sparse representations of sensory input. Technical Report RNI-04-1 (2004): see Rehn & Sommer (2006) J. Comp. Neurosci.

G. Glatting, F. M. Mottaghy, J. Karitzky, A. Baune, F. T. Sommer, G. B. Landwehrmeyer, S. N. Reske: Improving binding potential analysis in [11C]raclopide PET studies using cluster analysis. Medical Physics 31 (4) (2004) 902-906 pdf

J. A. Hirsch, L. M. Martinez, C. Pillai, J.-M. Alonso, Q. Wang, F. T. Sommer: Functionally distinct inhibitory neurons at the first stage of visual cortical processing. Nature Neuroscience 6 (12) (2003) 1300 - 1308 pdf

F. T. Sommer, T. Wennekers: Models of distributed associative memory networks in the brain. Theory in Biosciences (122) (2003) 70 - 86 pdf

Eds: F. T. Sommer, A. Wichert: Exploratory analysis and data modeling in functional neuroimaging. MIT Press, Boston, MA (2003) link to publisher (table of contents, etc.)

A. Knoblauch, F. T. Sommer: Synaptic plasticity, conduction delays, and inter-areal phase relations of spike activity in a model of reciprocally connected areas. Neurocomputing (52-54) (2003) 301-306 pdf

V. Schmitt, R. Koetter, F. T. Sommer: The impact of thalamo-cortical projections on activity spread in cortex Neurocomputing (52-54) (2003) 919-924 pdf

Recent talks

Spike Timings Relative to Retinal Oscillations Carry Visual Information to Cortex. Talk given at the Brain Network Dynamics Conference 2007 video and slides

Can high level perception use dynamical processes in early visual stages? Talk given at the Workshop "High-Level Perception and Low-Level Vision: Bridging the Semantic Gap", at the Santa Fe Institute, October 8-10, 2007.

Software

Tool for analysis of functional neuroimaging: The brain positioning software (BPS) gives access to the Brodmann atlas and can be called directly from the SPM data analysis software.

Workshops, Conferences and Teaching Courses

Workshops and conferences:

• COSYNE 2008: Workshop chair
• COSYNE 2007: Workshop chair -> COSYNE 2007 workshop program
• NIPS 2005: Program chair for Neuroscience -> NIPS 2005 program
• CNS 2002 workshop organizer: Neural assemblies -> Neural assemblies workshop
• NIPS 2000 workshop organizer: Explorative analysis and data modeling in functional neuroimaging

Graduate teaching at UC Berkeley:

• Neural Computation (2006; teaching participation at course VS298)
• Theoretical and computational neuroscience (2003, 2005; teaching participation at course MCB262/PSYCH290P)

Graduate teaching at University of Ulm (Germany):

Summer courses:

• Statistics of natural signals (2005)

Semester courses (1997-2002):

• Information retrieval and associative memory
• Computational Neuroscience
• Theoretical methods for the interpretation of medical functional imaging data
• Information Retrieval
• Associative memories: conventional and neuronal
• Neural Cell Assemblies

Neuroscience Publications by Theme

For a brief description of some of the research projects, see synopsis of research.

Computational models and analysis of cell physiology in the early visual system

X. Wang, Y. Wei, V. Vaingankar, Q. Wang, K. Koepsell, F. T. Sommer, J. A. Hirsch: Feedforward excitation and inhibition evoke dual modes of firing in the cat’s visual thalamus during naturalistic viewing. Neuron 55 (2007) 465-478. See also the preview about this paper: P. Reinagel: The inner life of bursts. Neuron 55 (2007) 339-341

M. Rehn, F. T. Sommer: A network that uses few active neurones to code visual input predicts the diverse shapes of cortical receptive fields. J. Comp. Neurosci. 22 (2) 135-146 (2007). pdf Earlier online prepublication SpringerLink DOI 10.1007/s10827-006-003-9 (2006)

M. Rehn, F. T. Sommer: Storing and restoring visual input with collaborative rank coding and associative memory. Neurocomputing 69 (10-12) (2006) 1219-1223 pdf

L. M. Martinez, Q. Wang, R. C. Reid, C. Pillai, J.-M. Alonso, F. T. Sommer, J. A. Hirsch: Receptive field structure varies with layer in the primary visual cortex. Nature Neuroscience 8 (12) (2005) 372 - 379 pdf

J. A. Hirsch, L. M. Martinez, C. Pillai, J.-M. Alonso, Q. Wang, F. T. Sommer: Functionally distinct inhibitory neurons at the first stage of visual cortical processing. Nature Neuroscience 6 (12) (2003) 1300 - 1308 pdf

Mechanisms of memory in realistic neural networks

Long-term memory

F. T. Sommer, T. Wennekers: Associative memory in networks of spiking neurons Neural Networks 14 (6-7) Special Issue: Spiking Neurons in Neuroscience and Technology (2001) 825 - 834 pdf

F. T. Sommer, T. Wennekers: Modeling studies on the computational function of fast temporal structure in cortical circuit activity Journal of Physiology - Paris 94 (5/6) (2000) 473-488 pdf

F. T. Sommer: On cell assemblies in a cortical column Neurocomputing (32-33) (2000) 517 - 522 pdf

T. Wennekers, F. T. Sommer: Gamma-oscillations support optimal retrieval in associative memories of two-compartment neurons Neurocomputing 26-27 (1999) 573 - 578 pdf

T. Wennekers, F. T. Sommer, G. Palm: Iterative Retrieval in Associative Memories by Threshold Control of Different Neural Models In: Supercomputers in Brain Research: From Tomography to Neural Networks World Scientific Publishing Comp (1995) 301-319

Short-term memory

A. Knoblauch, T. Wennekers, F. T. Sommer: Is voltage dependent synaptic transmission in NMDA receptors a robust mechanism for working memory? Neurocomputing (44-46) (2002) 19-24 pdf

U. Vollmer, F. T. Sommer: Coexistence of short and long term memory in a model network of realistic neurons Neurocomputing (38-40) (2001) 1031 - 1036 pdf

Large-scale integration of cortical representations

F. T. Sommer, T. Wennekers: Models of distributed associative memory networks in the brain Theory in Biosciences (122) (2003) 70 - 86 pdf

Associative memory in reciprocal cortico-cortical projections

F. T. Sommer, T. Wennekers: Associative memory in a pair of cortical cell groups with reciprocal projections Neurocomputing (38-40) (2001) 1575 - 1580 pdf

F. T. Sommer, T. Wennekers, G. Palm: Bidirectional completion of cell assemblies in the cortex Computational Neuroscience: Trends in Research 1998, Plenum Press, New York, (1998) ps

Large-scale integration relying on neural oscillations

A. Knoblauch, F. T. Sommer: Spike-timing dependent plasticity can form "zero-lag" links for cortical oscillations Neurocomputing (58-60) 185 - 190 (2004) pdf

A. Knoblauch, F. T. Sommer: Synaptic plasticity, conduction delays, and inter-areal phase relations of spike activity in a model of reciprocally connected areas Neurocomputing (52-54) (2003) 301-306 pdf

Models of macroscopic activity spread in cortex

V. Schmitt, R. Koetter, F. T. Sommer: The impact of thalamo-cortical projections on activity spread in cortex Neurocomputing (2003) (52-54) (2003) 919-924 pdf

R. Kötter and F. T. Sommer: Global relationship between anatomical connectivity and activity propagation in the cerebral cortex Phil. Trans. R. Soc. Lond. B (355) (2000) 127 - 134 pdf

F. T. Sommer, R. Kötter: Simulating a Network of Cortical Areas Using Anatomical Connection Data in the Cat Computational Neuroscience: Trends in Research 1997, Plenum Press, New York (1997) 511-517 ps

R. Koetter, P. Nielsen, J. Dyhrfjeld, F. T. Sommer, G. Northoff: Multi-level integration of quantitative neuroanatimical data Chapter in Computational Neuroanatomy: Principles and Methods. Ed.: G. A. Ascoli, Humana Press Inc., Totowa, NJ (2002)

Theory of associative memory

Bayesian theory of autoassociative memory

F. T. Sommer, P. Dayan: Bayesian Retrieval in Associative Memories with Storage Errors. IEEE Transactions on Neural Networks 9 (4) (1998) 705-713 pdf

Bidirectional sparse associative memory

F. T. Sommer, G. Palm: Improved Bidirectional Retrieval of Sparse Patterns Stored by Hebbian Learning. Neural Networks 12 (2) (1999) 281 - 297 pdf

F. T. Sommer, G. Palm: Bidirectional Retrieval from Associative Memory. Advances in Neural Information Processing Systems 10, MIT Press, Cambridge, MA (1998) 675 - 681 pdf

Capacity analysis of recurrent sparse autoassociative memories

F. Schwenker, F. T. Sommer, G. Palm: Iterative Retrieval of sparsely coded associative memory patterns. Neural Networks 9 (1996) 445-455 pdf

Capacity analysis of sparse pattern recognition

G. Palm, F. T. Sommer: Information capacity in recurrent Mc.Culloch-Pitts networks with sparsely coded memory states. Network 3 (1992) 177-186 pdf

G. Palm, F. T. Sommer: Information and pattern capacities in neural associative memories with feedback for sparse memory patterns. In: Neural Network Dynamics, Springer New York (1992). Eds.: J.G.Taylor, E.R.Caianello, R.M.J.Cotterill, J.W.Clark, 3-18

Analysis of local learning rules

G. Palm, F. T. Sommer: Associative data Storage and Retrieval in Neural Nets. In: Models of Neural Networks III, Springer New York (1996) Eds: E.Domany, J.L.van Hemmen, K.Schulten, 79-118 pdf

Book, PhD-Thesis (in german)

F. T. Sommer: Theorie neuronaler Assoziativspeicher - Lokales Lernen und iteratives Retrieval von Information. Verlag Hänsel-Hohenhausen (1993) ISBN 3-89349-901-6 ps

Neuroimaging

Edited book

Eds: F. T. Sommer, A. Wichert: Exploratory analysis and data modeling in functional neuroimaging. MIT Press, Boston, MA (2003) link to publisher (table of contents, etc.)

General issues of Neuroimaging

F. T. Sommer, J. A. Hirsch, A. Wichert: Theories, data analysis and simulation models in neuroimaging - an overview In Exploratory analysis and data modeling in functional neuroimaging. Eds.: F.T. Sommer and A. Wichert, MIT Press, Boston, MA (2003) pdf

V. Schmitt, A. Wichert, J. Grothe, F. T. Sommer: The brain positioning software. In: A practical guide of neuroscience databases and associated tools, Ed. R. Koetter, Kluwer, NY (2002)

Unsupervised method of detecting functional activity in Neuroimaging

A. Wichert, B. Abler, J. Grothe, H. Walter, F. T. Sommer: Exploratory analysis of event-related fMRI demonstrated in a working memory study. In Exploratory analysis and data modeling in functional neuroimaging. Eds.: F.T. Sommer and A. Wichert, MIT Press, Boston, MA (2003) pdf

A. Wichert, H. Walter, G. Groen, A. Baune, J. Grothe, A. Wunderlich, F. T. Sommer: Detection of delay selective activity during a working memory task by explorative data analysis. Neuroimage (13) (2001) 282

A. Baune, F. T. Sommer, M. Erb, D. Wildgruber, B. Kardatzki, G. Palm, W. Grodd: Dynamical Cluster Analysis of Cortical fMRI Activation. NeuroImage 6 (5) (1999) 477 - 489 pdf

Analysis techniques in Positron Emission Tomography

G. Glatting, F. M. Mottaghy, J. Karitzky, A. Baune, F. T. Sommer, G. B. Landwehrmeyer, S. N. Reske: Improving binding potential analysis in [11C]raclopide PET studies using cluster analysis. Medical Physics 31 (4) (2004) 902-906 pdf

A. Baune, A. Wichert, G. Glatting, F. T. Sommer: Dynamical cluster analysis for the detection of microglia activation in Artificial Neural Nets and Genetic Algorithms. Eds. V. Kurkova, N. C. Stelle, R. Neruda, M. Karny. Springer, Wien (2001) 442 - 445

J. Ruckgaber, G. Glatting, J. Karitzky, A. Baune, F. T. Sommer, B. Neumaier, S. N. Reske: Clusteranalyse in der Positronen-Emissions-Tomographie des Hirns mit C-11-PK11195. Nuklearmedizin (40) (2001) A95

Neural associative memories in information technology

M. Rehn, F. T. Sommer: Storing and restoring visual input with collaborative rank coding and associative memory. Neurocomputing 69 (10-12) (2006) 1219-1223 pdf

G. Palm, F. Schwenker, F. T. Sommer, A. Strey: Neural associative memory. In Associative Processing and Processors, Eds. A. Krikelis and C. C. Weems, IEEE CS Press, Los Alamitos, CA, USA (1997) 307-326 ps

F. T. Sommer, F. Schwenker, G. Palm: Assoziative Speicher als Module in informationsverarbeitenden Systemen. In: Contributions to the Workshop Aspekte Neuronalen Lernens, Eds. L.Cromme, J. Wille, T. Kolb Tech Report, TU Cottbus M-01/1995 (1995)

G. Palm, F. Schwenker, F. T. Sommer: Associative memory and sparse similarity preserving codes. In: From Statistics to Neural Networks: Theory and Pattern Recognition Applications, Ed. V.Cherkassky, Springer NATO ASI Series F, New York (1994) 282-302

Earlier Publications in Physics

P. Frodl, F. T. Sommer, K. Hau, F. Wahl: On the effective interaction of two hydrogen centres in Niobium. Z. f. Naturforsch. 43a (1990) 857-866

K. Hau, P. Frodl, M. Gnirß, F. T. Sommer, F. Wahl: A Microscopic Theory of a alpha-Phase Hydrogen in Niobium. Z. f. physikalische Chemie 163 (1989) 549-554

F. T. Sommer, K. Hau, P. Frodl, F. Wahl: Calculation of the excitation energies of a hydrogen impurity in Niobium. Z. f. Naturforsch. 43a (1988) 923-929

K. Hau, P. Frodl, F. T. Sommer, F. Wahl: A microscopic theory of a single hydrogen centre in Niobium. Z. f. Naturforsch. 43a (1988) 914-922

Classical Music

I studied music phenomenology and music practice by attending courses and rehearsals of Sergiu Celibidache in Stuttgart and Munich. As an amateur violinist I was member of the university orchestras in Tübingen and Düsseldorf and in a few chamber ensembles. Occasional freelance writing about music (Music manual, Klassik heute, CD booklet texts).

Music texts (to come)

Strongest listening recommendations

• Johann Sebastian Bach: Sonaten und Partiten for solo violin, Ida Haendel, 1996, Testament SBT 2090 (These pieces unfold a univers worth a lifetime to explore. There is a lot that can go wrong with playing these pieces: This recording gives perhaps the most direct and natural access to the univers. But note also the remarkable recording by the young Hilary Hahn)

• Anton Bruckner: 4th Symphony, Sergiu Celibidache, Munich Philharmonic Orchestra, 1996, EMI (Celibidache's choice of tempi makes the last movement with its coda a revelation.)

• Allan Petterssen: 7th Symphony, Sergiu Commissiona, Swedish Radio Symphony Orchestra, 1990, Caprice CAP21411 (One symphonic movement of forty odd minutes, written to capture the experience of modern mankind.)

• Franz Schubert: Eine Winterreise, Marko Rothmüller (baritone), Suzanne Gyr (piano), 1945 (Schubert's Winterreise is a microcosm of human experience and Rothmueller's voice gives it the most natural expression. Probably one of the most touching recordings ever that in my opinion surmounts in strength and directness the praised recordings by Diedrich Fischer-Dieskau.)

The Family Business

Hanns J. Sommer (University of Kassel); Julius Sommer, 1871-1943 (Technical University of Gdansk); Karl von Seebach, 1839-1880 (University of Göttingen)

Funding

Last, but not least. My research is currently funded by the Hawkins-Strauss trust, National Science Foundation and Google. In the past I received support from the German Science Foundation, the Ministry of Education and Research of Baden-Wuerttemberg and by the Wilhelm-Schweizer-Zinnfiguren GmbH. I am also indebted to the public university system of the Federal Republic of Germany.