Yaqing Su on Neural Coding of Pitch Cues in the Auditory Midbrain
Pitch is critical to auditory perception. It’s an important cue for separating sounds in a cocktail party. It binds a speech signal together so you hear speech instead of a bunch of chirps. Yet, the exact mechanism that our brain uses to hear the pitch of a signal is not known. Yaqing Su will be talking about evidence she has found that suggests that pitch is perceived with a combination of measures, effectively sidestepping the argument about place vs. time. This will be fun.
Who: Yaqing Su (Boston University)
What: Neural Coding of Pitch Cues in the Auditory Midbrain
When: Fri, 02/16/2018 - 10:30am - 12:00pm
Where: CCRMA Seminar Room
Why: Because pitch is pretty critical to our perception!
Bring your favorite pitch perceiver and we’ll talk about how it works!
Neural Coding of Pitch Cues in the Auditory Midbrain
Abstract
Pitch is an auditory percept related to the periodicity and harmonicity of sound. Despite extensive psychophysical and physiological studies over many decades, neural mechanisms that give rise to pitch perception remain incompletely understood. In the auditory periphery, neurons can convey pitch information via a temporal code to periodicity and a place code to resolved harmonics. In the auditory cortex, a pitch center where single neurons directly represent pitch by their firing rates has been identified in marmoset monkeys. However how the peripheral codes are transformed into a cortical pitch code is far from clear.
An understanding of such transformation will shed light on the representation and extraction of pitch in the auditory system. The goal of this work is to fill this gap by studying neural coding of pitch cues in the auditory midbrain. We identified three available neural codes using single-neuron recording in awake rabbits: a rate-place code for resolved harmonics inherited from periphery, a non-tonotopic rate code for envelope repetition rate that presumably arises in the midbrain, and a temporal code for envelope repetition rate. These codes could be qualitatively reproduced by a simple computational model.
Bio
Yaqing Su is a graduate student in Biomedical Engineering at Boston University. She works with Dr. Bertrand Delgutte at Harvard Medical School on neural mechanism of pitch in the auditory midbrain of awake rabbits. Prior to graduate school she received her BS in Electrical Engineering at Tsinghua University, China. In the past summer, Yaqing briefly digressed from rabbit physiology and did an internship at Starkey Hearing Research Center, where she combined psychoacoustic and EEG to study consonant perception in hearing impaired humans.