University of Minnesota
Department of Biomedical Engineering

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Hugh Lim

Hubert H. Lim








Neural Prostheses, Auditory Neuroscience, Neural Plasticity

The goal of the lab is to push the development and translation of brain-machine interfaces from scientific concept into clinical application with close collaboration with clinicians and industry. Brain-machine interfaces span a broad array of applications and consist of either direct connection of a device to neurons within the brain or neural communication through noninvasive techniques, such as EEG recordings and transcranial magnetic or ultrasound stimulation. The initial focus of my lab is to develop and improve invasive and noninvasive neurostimulation approaches for treating hearing disorders and pain.

We are currently working on eight general areas of research:

  1. The anatomical and functional organization of the ascending and descending auditory pathways involved with sound processing, attention and plasticity.

  2. Deep brain stimulation technologies and stimulation strategies (open- and closed-loop algorithms) to treat deafness, tinnitus or hyperacusis.

  3. Cortical stimulation techniques (direct stimulation or transcranial magnetic stimulation) to treat tinnitus or hyperacusis.

  4. Noninvasive ultrasound stimulation technologies and paradigms to activate the brain, peripheral nerves, muscles, and organs.

  5. A new noninvasive neuromodulation approach to treat brain disorders that we call Multimodal Synchronization Therapy (mSync), which combines activation of auditory, somatosensory, visual, motor, limbic, cognitive and other multimodal pathways to modulate different parts of the brain based on timing of convergence and plasticity principles.

  6. We are developing flexible and wearable technologies to implement noninvasive neuromodulation, such as mSync, in which the patients can take home the device and fit their own parameters in a comfortable environment. The vision for these wearable sensors and actuators is to enable real-time modulation and monitoring of physiological properties of the body and brain towards achieving a healthy state.

  7. Development of a new type of laser-based hearing aid using optoacoustic principles.

  8. Incorporation of associational plasticity and stress relaxation techniques into traditional neuromodulation approaches to help strengthen and shape the therapeutic effects.

The lab employs various experimental and engineering techniques in animals and humans to understand the brain and how to successfully implement a neural device. This includes acute and chronic implantation of electrode arrays into the animal brain to investigate how neurons codes for different sound features as well as the effects of electrical or ultrasound activation of multiple auditory and non-auditory pathways on neural coding, perception, and behavior. Various electrophysiological and modeling techniques are also used to investigate the functional and plasticity circuitry of the auditory system, which is important for understanding how to improve and optimize stimulation strategies for treating hearing disorders. By performing imaging and psychophysical studies in humans in response to various types of stimulation and interventions, and linking these results to those obtained in animals, we then obtain a better understanding of neural processing within the human brain that can guide the development of the next generation of neural technologies for improving hearing disorders.

Although the main focus of the lab is to develop improved neural devices for hearing applications, we are expanding our techniques and technologies to address other clinical applications, including pain and stress/anxiety.


  1. Lim HH, Shannon RV. "Two Laskers and Counting: Learning From the Past Enables Future Innovations With Central Neural Prostheses." Brain Stimulation, 8(3): 439-41, 2015. Invited Editorial

  1. Lim HH, Lenarz T. "Auditory Midbrain Implant: Research and development towards a second clinical trial." Hearing Research 322: 212-223, 2015.

  1. Markovitz CD, Smith BT, Gloeckner CD, Lim HH. "Investigating a new neuromodulation treatment for brain disorders using synchronized activation of multimodal pathways." Scientific Reports 5: 9462, 2015.

  1. Berding G, Wilke F, Rode T, Haense C, Joseph G, Meyer GJ, Mamach M, Lenarz M, Geworski L, Bengel FM, Lenarz T, Lim HH.  "Positron emission tomography imaging reveals auditory and frontal cortical regions involved with speech perception and loudness adaptation."  PLoS One 10(6): e0128743, 2015.

  1. Czanner G, Sarma SV, Ba D, Eden UT, Wu W, Eskandar E, Lim HH, Temeranca S, Suzuki WA, Brown EN.  "Measuring the signal-to-noise ratio of a neuron."  Proceedings of the National Academy of Sciences of the USA 112(23): 7141-7146, 2015.

  1. Plourde E, Rode T, Lim HH.  "A contribution of trained parameters to the goodness of fit of a Bayesian neural encoding model for the auditory system." Proceedings of the 7th International IEEE EMBS Conference on Neural Engineering 7: 910-913, 2015.

  1. Straka MM, Hughes R, Lee P, Lim HH.  "Descending and tonotopic projection patterns from the auditory cortex to the inferior colliculus."  Neuroscience 300: 325-337, 2015.

  1. Markovitz CD, Hogan PS, Wesen KA, Lim HH. "Pairing broadband noise with cortical stimulation induces extensive suppression of ascending sensory activity." Journal of Neural Engineering, 12(2), 2015.

  1. Offutt SJ, Ryan KJ, Konop AE, Lim HH. "Suppression and facilitation of auditory neurons through coordinated acoustic and midbrain stimulation: investigating a deep brain stimulator for tinnitus." Journal of Neural Engineering, 11(6), 2014.

  1. Straka MM, Schmitz S, Lim HH. "Response features across the auditory midbrain reveal an organization consistent with a dual lemniscal pathway." Journal of Neurophysiology, 112(4): 981-98, 2014.

  1. Straka MM, McMahon M, Markovitz CD, Lim HH. "Effects of location and timing of co-activated neurons in the auditory midbrain on cortical activity: implications for a new central auditory prosthesis." Journal of Neural Engineering, 11(4), 2014.

  1. Straka MM, Schendel D, Lim HH. "Neural integration and enhancement from the inferior colliculus up to different layers of auditory cortex." Journal of Neurophysiology, 110(4): 1009-1020, 2013.

  1. Gloeckner CD, Smith BT, Markovitz CD, Lim HH. "A new concept for non-invasive tinnitus treatment utilizing multimodal pathways." Proceedings of the 35th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 3122-3125, 2013.

  1. Calixto R, Salamat B, Rode T, Hartmann T, Volckaerts B, Ruther P, Lenarz T, Lim HH. "Investigation of a new electrode array technology for a central auditory prosthesis." PLoS One, 8(12), 2013.

  1. Rode T, Hartmann T, Hubka P, Scheper V, Lenarz M, Lenarz T, Kral A, Lim HH. "Neural representation in the auditory midbrain of the envelope of vocalizations based on a peripheral ear model." Frontiers in Neural Circuits, 7(166), 2013.

  1. Markovitz CD, Tang TT, Lim HH. "Tonotopic and localized pathways form primary auditory cortex to the central nucleus of the inferior colliculus."  Frontiers in Neural Circuits, 7(77), 2013.

  1. Johnson MD, Lim HH, Netoff TI, Connolly AT, Johnson N, Roy A, Holt A, Lim KO, Carey JR, Vitek JL, He B. "Neuromodulation for brain disorders: Challenges and opportunities." IEEE Transactions on Biomedical Engineering, 60(3): 610-624, 2013.

  1. Lim HH, Lenarz M, Joseph G, Lenarz T. "Frequency representation within the human brain: Stability versus plasticity." Scientific Reports, 3: 1474, 2013.

  1. McKay CM, Lim HH, Lenarz T. "Temporal processing in the auditory system: Insights form the auditory midbrain implantees." Journal of the Association for Research in Otolaryngology 14: 103-124, 2013.

  1. Markovitz CD, Tang TT, Edge DP, Lim HH. "Three-dimensional brain reconstruction of in vivo electrode tracks for neuroscience and neural prosthetic applications." Frontiers in Neural Circuits, 6(39), 2012.

  1. Calixto R, Lenarz M, Neuheiser A, Scheper V, Lenarz T, Lim HH. "Co-activation of different neurons along the isofrequency laminae of the inferior colliculus elicits enhanced cortical activation." Journal of Neurophysiology 108: 1199-1210, 2012.

  1. Neuheiser A, Lenarz M, Reuter G, Calixto R, Nolte I, Lenarz T, Lim HH. "Effects of pulse phase duration and location of stimulation within the inferior colliculus on auditory cortical evoked potentials in a guinea pig model." Journal of the Association for Research in Otolaryngology 11: 689-708, 2010.

  1. Zhang K, Wenzel GI, Balster S, Lim HH, Lubatschowski H, Lenarz T, Ertmer W, Reuter G. "Optoacoustic induced vibrations within the inner ear." Optics Express, 17(25): 23037-23043, 2009.

  1. Wenzel GI, Balster S, Zhang K, Lim HH, Reich U, Massow O, Lubatschowski H, Ertmer W, Lenarz T, Reuter G. "Green laser light activates the inner ear." Journal of Biomedical Optics, 14(4): 044007, 2009.

  1. Lim HH, Lenarz T, Anderson DJ, Lenarz M. "The Auditory Midbrain Implant: Effects of electrode location." Hearing Research, 242: 74-85, 2008.

  1. Lim HH, Lenarz T, Joseph G, Battmer RD, James F. Patrick, Lenarz M. "Effects of phase duration and pulse rate on loudness and pitch percepts in the first auditory midbrain implant patients: Comparison to cochlear implant and auditory brainstem implant results." Neuroscience, 154(1): 370-380, 2008.

  1. Czanner G, Dreyer AA, Eden UT, Wirth S, Lim HH, Suzuki WA, Brown EN. "Dynamic models of neural spiking activity." Proceedings of the 46th IEEE Conference on Decision & Control, 5812-5817, 2007.

  1. Lim HH, Lenarz T, Joseph G, Battmer RD, Samii A, Samii M, Patrick JF, Lenarz M. "Electrical stimulation of the midbrain for hearing restoration: Insight into the functional organization of the human central auditory system." Journal of Neuroscience, 27(49): 13541-13551, 2007.

  1. Lenarz M, Lim HH, Reuter G, Reich U, Marquardt N, Klingberg MN, Paasche G, Lenarz T, Stan A. "Auditory Midbrain Implant: Histomorphological effects of long-term implantation and electrical stimulation of a new DBS array." Otology & Neurotology, 28: 1045-1052, 2007.

  1. Lim HH, Anderson DJ. "Spatially distinct functional output regions within the central nucleus of the inferior colliculus: Implications for an Auditory Midbrain Implant." Journal of Neuroscience, 27(32): 8733-8743, 2007.

  1. Lim HH, Anderson DJ. "Antidromic activation reveals tonotopically organized projections from primary auditory cortex to the central nucleus of the inferior colliculus in guinea pig." Journal of Neurophysiology, 97: 1413-1427, 2007.

  1. Samii A, Lenarz M, Majdani O, Lim HH, Samii M, Lenarz T. "Auditory Midbrain Implant - A combined approach for vestibular schwannoma surgery and device implantation."  Otology & Neurotology, 28: 31-38, 2007.

  1. Lenarz M, Lim HH, Patrick JF, Anderson DJ, Lenarz T. "Electrophysiological validation of a human prototype auditory midbrain implant (AMI) in a guinea pig model." Journal of the Association for Research in Otolaryngology, 7: 383-398, 2006.

  1. Lenarz T, Lim HH, Reuter G, Patrick JF, Lenarz M. "The Auditory Midbrain Implant (AMI): A new auditory prosthesis for neural deafness. Concept and device description." Otology& Neurotology, 27: 840-845, 2006.

  1. Lim HH, Anderson DJ. "Auditory cortical responses to electrical stimulation of the inferior colliculus: Implications for an auditory midbrain implant." Journal of Neurophysiology, 96: 975-988, 2006.

  1. Lim HH, Anderson DJ. "Feasibility experiments for the development of a midbrain auditory prosthesis." Proceedings of the 1st International IEEE EMBS Conference on Neural Engineering, 193-196, 2003.

Book Chapters & Reviews

  1. Lim HH, Lenarz M, Lenarz T. Midbrain Auditory Prostheses. In: Auditory Prostheses: Cochlear Implants and Beyond, edited by Zeng F-G, Fay RR and Popper AN. Published by Springer as part of the Handbook of Auditory Research, 2011.

  1. Lim HH, Lenarz M, Lenarz T. Auditory midbrain implant: A review. Trends in Amplification 13(3): 149-180, 2009.

  1. Lenarz T, Lim HH, Joseph G, Reuter G, Lenarz M. [Central auditory prosthesis]. HNO 57(6): 551-562, 2009.

  1. Lim HH, Lenarz M, Lenarz T. A New Auditory Prosthesis Using Deep Brain Stimulation: Development and Implementation. In: Implantable Neural Prostheses: Techniques and Applications, edited by Zhou D and Greenbaum E. Published by Springer as part of the Biological and Medical Physics: Biomedical Engineering Series, 2009.

  1. Lenarz T, Lim HH, Lenarz M. The Auditory Midbrain Implant: Experimental and clinical results. In: Recent Advances in Otolaryngology, edited by Kier J, Moffat DA and Studhoff H. Published by The Royal Society of Medicine Press as part of the Recent Advances Series, 2008.