Hearing Research; Neurophysiology; Psychophysics; Auditory Prosthesis; Computational Neuroscience; Auditory Cortex
Our research addresses the brain mechanisms of hearing. There are two projects ongoing.
(1) Spatial Hearing: We are exploring the auditory cortical mechanisms that enable a listener to pick a sound out of a complex auditory scene on the basis of the sound’s location. Our recent experiments have demonstrated that the spatial selectivity of cortical neurons can sharpen dramatically when an animal is actively engaged in a sound-localization task compared to when it is idle. Parallel human psychophysical and animal physiological experiments are demonstrating that single cortical neurons can synchronize selectively to one of two sound sequences from closely separated locations under conditions in which a human listener would report two segregated “streams”.
(2) Auditory Nerve Electrode Arrays: We are testing the feasibility of a new mode of hearing replacement using arrays of electrodes implanted in the auditory nerve. Our short-term studies in anesthetized animals have shown substantial improvements compared to conventional cochlear implants. Ongoing studies will assess safety and efficacy of long-term stimulation in chronically implanted animals prior to eventual human trials.
Experimental approaches used in the lab include human and animal psychophysics, and single-unit neurophysiology in anesthetized and awake/behaving animals.
Middlebrooks, JC. Chronic deafness degrades temporal acuity in the electrically stimulated auditory pathway. JARO 19: 541-557. doi: 10.1007/s10162-018-0679-3, 2018,
Presacco, A, Middlebrooks, JC. Tone-evoked acoustic change complex (ACC) recorded in a sedated animal model. JARO https://doi.org/10.1007/s10162-018-0673-9, 2018.
Middlebrooks, JC: Masking release by combined spatial and masker-fluctuation effects in the open sound field. J Acoust Soc Am 142:3362-3375, 2017.
Yao, JD, Bremen, P, Middlebrooks, JC: Emergence of spatial stream segregation in the ascending auditory pathway. J. Neuroscience 35: 16199-16212, 2015.
Middlebrooks, JC: Sound localization. Handbook of Clinical Neurology 129:99-116, 2015.
Middlebrooks, JC, Nick, HS, Subramony, SH, Advincula, J, Rosales, RL, Lee, LV, Ashizawa, T, Waters, MF: Mutation in the Kv3.3 voltage-gated potassium channel causing spinocerebellar ataxia 13 disrupts sound-localization mechanisms. PLoS ONE, 8:e76749, 2013. PMC3792041
Middlebrooks, JC, Bremen, P: Spatial stream segregation by auditory cortical neurons. J Neurosci., 33:10986-11001, 2013. PMC3718378
Middlebrooks, JC, Onsan, ZA: Stream segregation with high spatial acuity. J Acoust Soc Am, 132:3896-3911, 2012.
Lee, C-C, Middlebrooks, JC: Auditory cortex spatial sensitivity sharpens during task performance. Nature Neurosci, 14:108-114, 2011
Middlebrooks, JC and Snyder, RL: Selective electrical stimulation of the auditory nerve activates a pathway specialized for high temporal acuity. J Neurosci, 30:1937-1946, 2010.
Middlebrooks, JC: Auditory cortex phase locking to amplitude-modulated cochlear-implant pulse trains. J Neurophysiol, 100:76-91, 2008.
Middlebrooks, JC, and Snyder, RL: Auditory prosthesis with a penetrating nerve array, JARO 8: 258-279, 2007.
Stecker, GC, Harrington, IA, Macpherson, EA, and Middlebrooks, JC: Spatial sensitivity in the dorsal zone (DZ) of cat auditory cortex, J. Neurophysiol. 94:1267-1280, 2005.
Stecker GC, Harrington IA, Middlebrooks, JC: Location coding by opponent neural populations in the auditory cortex. PLoS Biol 3(3): 520-528(e78), 2005.
Middlebrooks, JC: Effects of cochlear-implant pulse rate and inter-channel timing on channel interactions and thresholds, J. Acoust. Soc. Am, 116:452-468, 2004.
Mickey, BJ, and Middlebrooks, JC: Representation of auditory space by cortical neurons in awake cats, J. Neurosci., 23:8649-8663, 2003.
Macpherson, EA, and Middlebrooks, JC: Listener weighting of cues for lateral angle: the duplex theory of sound localization revisited, J. Acoust. Soc. Am. 111:2219-2236, 2002.
Bierer, JA, and Middlebrooks, JC: Auditory cortical images of cochlear-prosthesis stimuli: Dependence on electrode configuration, J. Neurophysiol. 87: 478-492, 2002.
Xu, L, Furukawa, S, and Middlebrooks, JC: Auditory cortical responses in the cat to sounds that produce spatial illusions, Nature 399:688-691, 1999.
Middlebrooks, JC, Clock AE, Xu L, Green DM: A panoramic code for sound location by cortical neurons. Science 264:842-844, 1994.
NIDCD RO1 DC000420: Cortical Representation of Auditory Space
Wellcome Trust Collaborative Award: A Multidisciplinary Approach to Understanding and Improving Hearing by Cochlear Implant Users
NIDCD R01 DC017182: Enhanced auditory prosthesis using a penetrating auditory-nerve electrode
Association for Research in Otolaryngology (ARO)
Acoustical Society of America
Society for Neuroscience
Interdepartmental Neuroscience Program
Center for Hearing Research
Center for Cognitive Neuroscience