Ralf Wessel

Titles
Associate Professor

Office Contact Information

Office
216 Crow
Mailbox

Physics Department, CB 1105
Washington University
One Brookings Drive
St. Louis, MO 63130-4899, USA

Phone
(314) 935-7976
Fax
(314) 935-6219

Research Interests

Arguably the biggest goal in modern neuroscience is to gain a deeper and more complete understanding of strongly correlated neural systems, known as microcircuits. A striking phenomenon of strongly correlated neural systems is visual perception. In broad strokes, it is intriguing to hypothesize that visual perception emerges from the interaction between incoming spatiotemporal stimuli and the internal dynamic state of neural networks. Yet, to date, a convincing computational framework for the processing of visual stimuli in neural circuits remains elusive.

To fill this gap, Dr. Wessel’s NeuroPhysics group seeks to delineate principles of visual information processing at the level of spatiotemporal network dynamics in optic tectum and visual cortex. The central component of the NeuroPhysics research program consists of in vitro electrophysiological recordings of cortical activity in the turtle eye-attached whole-brain preparation in response to computer-controlled visual stimulation of the retina. A key innovation of Dr. Wessel’s research lies in adapting quadruple intracellular whole-cell recording and multielectrode array extracellular recording techniques to the unfolded, yet intact, three-layer visual cortex during visual processing. The observed emergent phenomena, including oscillations, synchrony, and neuronal avalanches, are conceptualized using a framework informed by statistical physics and nonlinear dynamics. This synergy of advanced neurotechnology, comparative in vitro physiology, and physics-inspired theory provides a fertile opportunity to test the stated working hypothesis and to advance our understanding of cortical microcircuit function.

Publications

  • Gabbiani F, Metzner W, Wessel R, and Koch C (1996) From stimulus encoding to feature extraction in weakly electric fish. Nature 384:564-567. pdf
  • Luksch H, Khanbabaie R, and Wessel R (2004). Synaptic dynamics mediate sensitivity to motion independent of stimulus details. Nature Neuroscience 7:380-388. pdf
  • Brandt SF, Dellen BK, Wessel R (2006) Synchronization from disordered driving forces in arrays of coupled oscillators. Phys Rev Letters 96: 034104. pdf
  • Caudill MS, Brandt SF, Nussinov Z, Wessel R (2009) An intricate phase diagram of a prevalent visual circuit reveals universal dynamics, phase transitions and resonances. Phys Rev E 80: 051923. pdf
  • Lai D, Brandt S, Luksch H, Wessel R (2011) Recurrent antitopographic inhibition mediates competitive stimulus selection in an attention network. J Neurophysiol 105: 793-805. pdf

Ralf Wessel's Complete Publications List

Education

1992 Ph.D., University of Cambridge
1989 M.S., Technical University Munich

 

Professional History

Dr. Wessel obtained an MS in Physics from the Technical University Munich/Germany in 1989 and a Ph.D. in Physics from the University of Cambridge/England in 1992. During his postdoctoral training from 1993 to 1996 in neuroscience at UCSD in La Jolla, he was successively a Human Frontier Science Program Fellow and a German Research Council Fellow. In 1997, Dr. Wessel was appointed to Research Assistant Professor in the Department of Physics at UCSD. In 2000 he joined the faculty of Washington University in St. Louis as Assistant Professor of Physics and was promoted to Associate Professor in 2006. He also holds a joint appointment in the Department of Anatomy and Neurobiology at the Washington University School of Medicine.

In 2007, the Graduate Student Senate selected Dr. Wessel to receive Recognition for Excellence in Mentoring as part of the Outstanding Faculty Mentor Awards. These awards were created by graduate students in the Senate to honor faculty members whose commitment to graduate students and excellence in graduate training has made a significant contribution to the success of graduate students in Arts and Sciences at Washington University.