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Steven M. Bierer, Ph.D.
Senior Fellow sbierer@u.washington.edu
Department of Otolaryngology - HNS
Dr. Bierer is a biomedical engineer and neurophysiologist who has specific expertise in multiunit recording and neural stimulation. Dr. Bierer is primarily responsible for the development of the techniques and recording technologies necessary for performing deep multiple single unit recordings in the brainstem of primates. Dr. Bierer will supervise the multiunit recordings and will develop techniques to obtain improved isolation from single units, and multiple unit recordings from the vestibular nuclei during rotational and electrical stimulation of the vestibular end organ.
Research / Teaching Experience (top) ±
University of Washington :: 09/2005-2006
I continued my research in the area of cochlear implant physiology as a postdoctoral fellow under the supervision of Edwin Rubel and Jay Rubinstein. My main objective was to evaluate the temporal properties of neurons in the guinea pig inferior colliculus to various rates of modulated and unmodulated electrical pulse trains. The motivating hypothesis was that temporal acuity varies systematically across the nucleus, orthogonal to the tonotopic axis, in a manner similar to that of acoustic stimulation. I was also exploring the relationship between temporal acuity and the spectral, or spatial, extent of cochlear stimulation by comparing responses to narrow bipolar and broad monopolar cochlear implant configurations.
University of California, San Francisco :: 03/2004-08/2005
In the Epstein Laboratory, under the direction of Russell Snyder and Patricia Leake, I initiated a study to better understand how the brain encodes electrical signals delivered to the inner ear by a cochlear implant. I recorded ensemble activity of a large number of neurons in the guinea pig inferior colliculus using a 16-channel electrode array. These recordings revealed distinct patterns of suppressive interaction in response to signals delivered from two cochlear implant channels. Understanding the nature of the temporal and spatial interactions may lead to improvements in the design and processing strategies of cochlear implants.
University of California, Berkeley :: 08/2001-12/2003
As a postdoctoral fellow in the laboratory of Ralph Freeman, I compared the spatial and temporal processing of simple cells in areas 17 and 18 of the cat visual cortex. In area 18, receptive fields generated by reverse-correlation to white noise exhibit shorter latencies and indicate preferences for lower spatial and higher temporal frequencies. The spatial and temporal properties are highly correlated in both cortical regions. This functional dichotomy, in part, reflects the distinct subcortical input received by area 17 and area 18, yet it also implies a major difference in the way the inputs are processed at the cortical level. In related research, I examined the nonlinear and binocular properties of simple and complex cells.
University of Michigan :: 09/1994-05/2001
My dissertation research, advised by David Anderson, was focused on improving the recording capabilities of silicon-substrate electrodes. I developed signal processing techniques and refined electrode design to substantially reduce the level of background neural noise in multi-channel recordings. These methods were applied to the analysis of cell-to-cell interactions in the dorsal cochlear nucleus of the guinea pig, revealing a possible modulatory role of a class of inhibitory cells.
In a related project, I developed a histological method to mark electrode sites in tissue using fluorescent stains and electro-deposited metal. These marks helped to pinpoint the region of brain tissue from which recordings were made during an experiment.
University of Michigan :: 01/1995-10/1995
For testing of an auditory nerve stimulating electrode, I developed a data acquisition and stimulus generation system to record evoked brain potentials. I also aided in the collection and analysis of the data.
Johns Hopkins University :: 05/1991-08/1994
I designed and fabricated an electrode array for the in vitro study of pancreatic beta cells, as part of a master's thesis project under Norman Sheppard. The construction of the array was based on thin-film micro-fabrication techniques. I developed a computer model to simulate the dynamic electrical properties of a beta cell and its interface with a metal electrode. I also assisted in the production and evaluation of conductive polymers for use in biocompatible glucose sensors.
Johns Hopkins University :: 05/1990-09/1990
Under the supervision of Murray Sachs, I developed a computer model to characterize the responses of neurons to acoustic stimuli.
University of California, Berkeley :: 10/2002-12/2002
I taught a 3-week component of an optometry graduate-level class. Lectures were focused on the anatomy and physiology of the central pathways of vision. I was responsible for developing the lectures, providing on-line supporting material, and creating questions for examination.
Johns Hopkins University :: 01/992-05/1992 and 01/1993-05/1993
I was a teaching assistant for an engineering senior- and graduate-level course, Biomedical Sensors, taught by Leslie Tung. My main responsibility was to set up and conduct laboratory exercises to demonstrate the properties and applications of mechanical, chemical, optical, and thermal sensors. I also formulated and graded homework assignments and examinations, conducted review sessions, and presented several class lectures.
Specific and Technical Accomplishments (top) ±
University of California, Berkeley - 04/2002
NEI Vision Science Training Grant (National Institutes of Health)
University of Michigan - 09/1994
Department of Education GAANN Fellowship
Bierer SM. “Optimization of multi-neuron recordings using micro-machined electrode arrays”. Ph.D. Dissertation, Department of Biomedical Engineering. University of Michigan. 2001.
Bierer SM and Anderson DJ. “Multi-channel spike detection and sorting using an array processing technique”. Neurocomputing. 26: 947-956. 1999.
Bierer SM, Bonham BH, and Snyder RL. “Inferior Colliculus Responses to Two-channel Cochlear Implant Stimulation”. Association for Research in Otolaryngology, New Orleans, LA. 2005.
Bierer SM and Freeman RD. “A comparison of response properties of cells in striate and extrastriate cortex”. Society for Neuroscience, New Orleans, LA. 2003.
Bierer SM and Anderson DJ. “Detecting action potentials in noise: an array processing approach”. Annals of Biomedical Engineering. 28 (Suppl. vol. 1): S-117. 2000.
Bierer SM and Anderson DJ. “Simultaneous recording of fusiform and cartwheel cells in the guinea pig dorsal cochlear nucleus”. Association for Research in Otolaryngology, St Petersburg Beach, FL. 2000.
Bierer SM and Anderson DJ. “Noise reduction of multi-channel neural activity using an array processing technique”. Computational Neuroscience, Santa Barbara, CA. 1998.
Bierer SM and Anderson DJ. “Analysis of dorsal cochlear nucleus activity recorded with a 16-channel microelectrode array”. Association for Research in Otolaryngology, St Petersburg Beach, FL. 1998.
Jones DA, Arts A, Bierer SM, and Anderson DJ. “Stimulation of the auditory nerve using a penetrating, thin film microelectrode array in cats”. Association for Research in Otolaryngology, St Petersburg Beach, FL. 1996.