Friedrich T. Sommer
Associate Adjunct Professor (Neuroscience)
Email: fsommer@berkeley.edu
Research areas: Systems and Computational Neuroscience, Cognitive and Behavioral Neuroscience
Our broad interest is understanding information processing in the brain. The approaches that we take include the design of methods to analyze neuroscientific data and the use of computer models of the brain at microscopic and at macroscopic levels.
The research on local processing focuses on the neuronal basis of long- and short-term memory and its role in sensory processing and cognition. For example, we employ techniques from Theoretical Physics, Information Theory and Bayesian reasoning to study associative memory in formal neural networks and also in those with closer correspondence to actual circuits. To date, the work has yielded efficient new technical algorithms for image retrieval and also served to guide design of computational models that permit the investigation of biological phenomena such as reverberating neural activity, spike synchronization, and gamma oscillations. Further, we collaborate with physiologists in projects that explore computational function of circuits in the early visual pathway.
Our projects on the macroscopic level include neuroimaging and models of computational anatomy. For instance, motivated by questions about how different regions of the brain are involved in working memory and voluntary movement, we developed novel multivariate methods to detect distributed patterns of activity in space and time. As well, we study how activity spreads across cortical regions by building computational models that relate experimentally observed patterns of cortical activation with known anatomical connections.
Selected Publications
Palm, G. and Sommer, F.T. 1992. Information capacity in recurrent McCulloch-Pitts networks with sparsely coded memory states Network 3: 177-186.
Sommer, F.T. and Dayan, P. 1998. Bayesian retrieval in associative memories with storage errors IEEE Transactions on Neural Networks 9: 705-713.
Sommer, F.T. and Palm, G. 1999. Improved bidirectional retrieval of sparse patterns stored by Hebbian learning Neural Networks 12: 281-297.
Baune, A., Sommer, F.T., Erb, M., Wildgruber, D., Kardatzki, B., Palm, G., and Grodd W. 1999. Dynamical cluster analysis of cortical fMRI activation NeuroImage 6: 477-489.
Kötter, R. and Sommer, F.T. 2000. Global relationship between anatomical connectivity and activity propagation in the cerebral cortex Philosophical Transactions of the Royal Society: Biological Sciences 355: 127-134.
Sommer, F.T. and Wennekers, T. 2000. Modeling studies on the computational function of fast temporal structure in cortical circuit activity Journal of Physiology, Paris 94: 473-488.
Hirsch, J.A., Martinez, J.M., Pillai, C., Alonso, J.-M., Wang, Q. and Sommer, F.T. 2003. Functionally distinct inhibitory neurons at the first stage of visual cortical processing Nature Neuroscience 6: 1300-1308.
Knoblauch, A. and Sommer, F.T. 2004. Spike-timing dependent plasticity can form “zero-lag” links for cortical oscillations Neurocomputing 58-60: 185-190.
Sommer, F.T. and Wennekers, T. 2005. Synfire chains with conductance-based neurons: internal timing and coordination with timed input Neurocomputing 65-66: 449-454.
