Auditory system

To discern speech or appreciate music, the human auditory system detects how pitch increases or decreases over time. However, the algorithms used to detect changes in pitch, or pitch motion, are incompletely understood. Here, using psychophysics, computational modeling, functional neuroimaging, and analysis of recorded speech, we ask if humans can detect pitch motion using computations analogous to those used by the visual system. We adapted visual stimuli to create novel auditory correlated noise stimuli that elicit robust pitch motion percepts. Crucially, these stimuli are inharmonic and pos

…on supervised learning, in which the auditory system is calibrated by exactly matching feedback signals from the precise visual system. But such cross-sensory calibration is not always feasible. It is unclear how to calibrate the auditory map when

An exquisite characteristic of the auditory system is its ability to sense a large range of sound intensities from whispers to loud alarm sounds, covering 6 orders of magnitude in acoustic pressure. Deficits of sound intensity processing may lead to hearing loss and/or major auditory perception distortions like tinnitus, the perception of phantom sounds, or hyperacusis, a reduced tolerance for moderate sound levels. Audiogenic seizures, reflex seizures induced by loud sounds, are a common feature of many mouse models for central nervous system disorders and may be seen as a model of auditory h

The tonotopic organization of the auditory system plays a crucial role in facilitating efficient processing of diverse auditory information that appears to be conserved across mammalian species. Approaches to date have mostly used electrophysiological or static approaches to map the representation of sound frequencies within the rodent auditory system, meaning that a comprehensive mapping in real-time was not feasible. Here, we used 7-Tesla fMRI in awake male rats to simultaneously determine tonotopic frequency representations in cortical and subcortical structures. Presentation of four differ

…processing in the early sensory systems is thought to be mostly preserved under anesthesia, based on stimulus tuning properties like those observed in wakefulness. However, in the absence of recordings tracking the activity of the same neurons across states, there is no evidence that anesthesia preserves peripheral one-to-one sensory representations. Here, tracking for the first time the same cochlear nucleus neurons across wakefulness and i

To make sense of the acoustic environment, the auditory system must segregate, based on their history, streams of sounds arriving at the ear simultaneously. This requires sensitivity to both the probability and the predictability of the different sounds in the stream. That the auditory system is sensitive to the probability of appearance of a sound is well established. Here we presented complex sound sequences of varying predictability to anesthetized mice. Neuronal responses in the mouse inferior colliculus (IC) were recorded using Cambridge NeuroTech and Neuropixels probes. Neurons exhibited

The auditory system must accurately represent sounds over a wide range of sound intensities. Spike-rate adaptation is one proposed mechanism for enhancing discrimination between salient foreground stimuli and background noise through dynamic adjustments in response sensitivity to the unfolding statistical structure of soundscapes. A critical aspect of this form of statistical learning is the interplay between feedforward and feedback pathways forming “listening loops” in the auditory brain. We performed simultaneous recordings of neuronal activity in the inferior colliculus (IC) and the primar

…This study examines how the auditory system copes with reverberation. We trained a linear model to recover a rich set of natural, anechoic sounds from their simulated reverberant cou

…of sound information throughout the auditory system remains an intense subject of research. Here, we used large-scale samples of neuronal activity from the auditory cortex, thalamus and inferior colliculus in mice and from a detailed cochlea model to identify key transformations of population representations of simple, short (~500ms) time-varying sounds in the auditory pathway. Using noise-corrected metrics, we measured the similarity of evoked population patterns across sounds. In subcortical regions, this measure shows that the full tem

…problems faced by the visual and auditory system, focusing on two issues. 1. How does the brain correct for discrepancies in the visual and auditory spatial reference frames? I will describe our recent discovery of a novel type of otoacoustic emission, the eye movement related eardrum oscillation, or EMREO (Gruters et al, PNAS 2018). 2. How does the brain encode more than one stimulus at a time? I will discuss evidence for neural time-division multiplexi

How does the brain decode the meaning of sound signals, such as music and courtship songs? We believe that the fruit fly Drosophila melanogaster is an ideal model for answering this question, as it offers a comprehensive range of tools and assays which allow us to dissect the mechanisms underlying sound perception and evaluation in the brain. During the courtship behavior, male fruit flies emit “courtship songs” by vibrating their wings. Interestingly, the fly song has a species-specific rhythm, which indeed increases the female’s receptivity for copulation as well as male’s courtship behavior