Skip to content

Richard A. Normann

Emeritus Distinguished Professor of Biomedical Engineering
Emeritus Professor of Ophthalmology & Visual Science

The Normann Lab
Brain and Behavior
Cellular Neuroscience






B.S. 1965, M.S. 1967, Ph.D. 1973, University of California, Berkeley; Staff Fellow, 1974-1979, National Institutes of Health, Bethesda, MD


Information processing in the vertebrate retina; phototransduction

The Normann laboratory is developing interfaces to the central and peripheral nervous systems for basic science and clinical applications. They have focused on two basic electrode array architectures: the Utah Electrode Array (UEA) consists of 100, 1.5 mm long silicon miconeedles that project out from a 4 mm x 4 mm x 0.25 mm thick substrate. The Utah Slanted Electrode Array (USEA) has a similar architecture but the lengths of the electrodes are graded from 0.5 mm to 1.5 mm. The UEA was designed for cortical applications, and the USEA was designed for use in the peripheral nervous systems.

We have used these interfaces to study parallel information processing by the central nervous system (visual and auditory cortex) and the control of muscle force and limb position by the peripheral nervous system. Ongoing projects include: the production of fatigue resistant, graded forces by the skeletal musculature, the control of multijoint forces in an entire limb, the production of sensory percepts in mammalian model systems by electrical stimulation of central and peripheral pathways, sight restoration in the blind by cortical electrical stimulation, and the stimulation of the cochlear nerve to evoke selective activation of auditory cortex as an auditory neuroprosthesis. Additional work is focused on moving from wired electrode arrays to wireless devices that will be powered inductively and will send data to external electronics via a radio frequency link.

Selected Publications:

Wilder, A.M., Hiatt, S.D., Dowden, B.R., Brown, N.A.T., Normann, R.A., and Clark, G.A. (2009) Automated stimulus-response calibration of high-electrode count neural implants. IEEE TNSRE, in press.

Dowden, B.R., Wilder, A.M., Hiatt, S.D., Normann, R.A., Clark, G.A., and Brown, N.A.T. (2009) Selective and graded recruitment of cat hamstring muscles. IEEE TNSRE, Aug. 10.1109/TNSRE.2008.2011988

Normann, R.A., et al. (2009) Toward the development of a cortically based visual neuroprosthesis. J Neural Eng, 6(3): p. 035001.

Normann, R.A. (2007) Technology Insight: Future Neuroprosthetic Therapies For Disorder Of The Nervous System. Nat. Clin. Pract. Neurol., 3:444-452.

Kim, S.J., Badi, A.N., and Normann, R.A. (2007) Selective Activation of Cat Primary Auditory Cortex via Direct Intraneural Auditory Nerve Stimulation. Laryngoscope, Jun;117(6):1053-1062.

Warren, D. J., and Normann, R. A. (2005) Functional reorganization of primary visual cortex induced by electrical stimulation in the cat. Vision Res., 45:551-565.

McDonnall, D., Clark, G.A. and Normann, R.A. (2004) Interleaved, Multi-Site Electrical Stimulation of Cat Sciatic Nerve Produces Fatigue-Resistant, Ripple-Free Motor Responses. IEEE Trans Biomed. Eng., 12:208-215.

McDonnall, D., Clark, G. A., and Normann, R. A. (2004) Selective motor unit recruitment via intrafascicular multielectrode stimulation. Can J Physiol Pharmacol., 82(8-9):599-609.

Stein, R. B., Weber, D., Aoyagi, Y., Prochazka, A., Wagenaar, J. B. M., Shoham, S., and Normann, R. A. (2004) Coding of position by simultaneously recorded sensory neurons in the cat dorsal root ganglion. J. Physiol., 560.3:883-896.

Branner, A., Stein, R. B., Fernandez, E., Aoyagi, Y, and Normann, R. A. (2004) Long-term stimulation and recording with a penetrating microelectrode array in cat sciatic nerve. IEEE Trans Biomed Eng., Jan; 51(1):146-157.

Hillman, T., Badi, A., Normann, R. A., Kertesz, T., and Shelton, C. (2003) Cochlear nerve stimulation with a 3-dimensional penetrating electrode array. Otol Neurotol., 24(5):764-768.

Badi, A. N., Hillman, T., Shelton, C., and Normann, R. A. (2002) A technique for implantation of a 3-dimensional penetrating electrode array in the modiolar nerve of cats and humans. Arch. Otoloryngol. Head Neck Surg. 128:1010-25.

Shoham, S., Halgren, E., Maynard, E. M., and Normann, R. A. (2001) Motor-cortical activity in tetraplegics. Nature Oct 25; 413(6858):793.

Warren, D. J., Fernández, E., and Normann, R. A. (2001) High-Resolution Two-Dimensional Spatial Mapping Of Cat Striate Cortex Using A 100 Microelectrode Array. Neuroscience 105(1):19-31.

Branner, A., Stein, R., and Normann, R. A. (2001) Selective stimulation using a slanted microelectrode array. J. Neurophysiol. 85:1585-94.

Normann, R. A., Warren, D. J., Ammermüller, J., Fernández, E., and Guillory, S. (2001) High-Resolution Spatio-Temporal Mapping Of Visual Pathways Using Multi-Electrode Arrays. Vision Research 41:1261-1275.

Fernández, E., Ferrandez, J. M., Ammermüller, J., and Normann, R. A. (2000) Population Coding in Spike Trains of Simultaneously Recorded Retinal Ganglion Cells. Brain Res. 887(1):222-229.

Perlman, I., and Normann, R. A. (1998) Light Adaptation and Sensitivity Controlling Mechanisms in Vertebrate Photoreceptors. Progress in Eye and Retinal Research 17(4):523-563.

Normann, R. A., Maynard, E. M., Guillory, K. S., and Warren, D. J. (1996) Cortical implants for the blind. IEEE Spectrum May, pp. 54-59.

Nordhausen, C. T., Rousche, P. J., and Normann, R. A. (1994) Optimizing recording capabilities of the Utah Intracortical Electrode Array. Brain Research. 637: 27-36.


Last Updated: 6/4/21