The general goal of the proposed research is to illuminate the relationship between neuronal activity and auditory function. Specifically we are interested (1) what are the psychophysical abilities of human and non- human subjects in integrating spectral and temporal features of sounds, and (2) how do auditory cortical single neuron responses relate to this ability as measured through psychophysical performance. Psychophysical measurements will be made from human and non-human subjects to determine their ability to discriminate temporally or spectrally complex sounds. We will then record single unit responses from non- human subjects while they discriminate sounds used in the psychophysical experiments. For one aim, we will investigate amplitude modulation as a function of sound duration and AM frequency and for the other aim investigate complex sound spectra. Using novel modifications of signal detection theory, we will determine the discriminative capabilities of neurons, and whether the firing of individual neurons is more closely associated with the physical attributes of sound or to the pscyhophysicaljudgement. These results will provide critical direct links between single neuron physiological function and psychophysical perfrormance. This data will add knowledge about the effects of cortical disruptions due to strokes trauma, and other degenerative diseases of the brain on hearing. Additionally, this study should add to the understanding of temporal acoustical processing which appears related to many of the effects of dyslexia and other developmental disorders. These results accordingly are of potential use for understanding and treating strokes and developmental disorders. Achieving the three aims will allow us to rigorously assess: (1) how spectral and temporal information is integrated and combined by the auditory central nervous system.

National Institute of Health (NIH)
National Institute on Deafness and Other Communication Disorders (NIDCD)
Research Project (R01)
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Special Emphasis Panel (ZRG1-IFCN-B (04))
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Platt, Christopher
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University of California Davis
Schools of Arts and Sciences
United States
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Downer, Joshua D; Rapone, Brittany; Verhein, Jessica et al. (2017) Feature-Selective Attention Adaptively Shifts Noise Correlations in Primary Auditory Cortex. J Neurosci 37:5378-5392
Downer, Joshua D; Niwa, Mamiko; Sutter, Mitchell L (2017) Hierarchical differences in population coding within auditory cortex. J Neurophysiol 118:717-731
Johnson, Jeffrey S; O'Connor, Kevin N; Sutter, Mitchell L (2015) Segregating two simultaneous sounds in elevation using temporal envelope: Human psychophysics and a physiological model. J Acoust Soc Am 138:33-43
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Downer, Joshua D; Niwa, Mamiko; Sutter, Mitchell L (2015) Task engagement selectively modulates neural correlations in primary auditory cortex. J Neurosci 35:7565-74
Niwa, Mamiko; Johnson, Jeffrey S; O'Connor, Kevin N et al. (2013) Differences between primary auditory cortex and auditory belt related to encoding and choice for AM sounds. J Neurosci 33:8378-95
Johnson, Jeffrey S; Yin, Pingbo; O'Connor, Kevin N et al. (2012) Ability of primary auditory cortical neurons to detect amplitude modulation with rate and temporal codes: neurometric analysis. J Neurophysiol 107:3325-41
Niwa, Mamiko; Johnson, Jeffrey S; O'Connor, Kevin N et al. (2012) Active engagement improves primary auditory cortical neurons' ability to discriminate temporal modulation. J Neurosci 32:9323-34
Niwa, Mamiko; Johnson, Jeffrey S; O'Connor, Kevin N et al. (2012) Activity related to perceptual judgment and action in primary auditory cortex. J Neurosci 32:3193-210
Petkov, Christopher I; Sutter, Mitchell L (2011) Evolutionary conservation and neuronal mechanisms of auditory perceptual restoration. Hear Res 271:54-65

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