Research

Sound and hearing are essential for human communication. Individuals with central auditory processing disorders often struggle with everyday interactions, sometimes finding even basic verbal communication challenging. Tinnitus — the perception of phantom sounds in the absence of actual acoustic stimulation — is one example of a disorder arising from dysfunction in the central auditory system, affecting more than 10% of the population.

Despite the critical role of hearing in communication, our understanding of how sounds are perceived and processed by the brain—especially within the central auditory system—remains limited. In contrast, much progress has been made in understanding the peripheral auditory system. Technologies such as cochlear implants and hearing aids are remarkable examples of translational research built upon basic discoveries in peripheral hearing mechanisms. However, the complex processing that occurs centrally, and particularly in the auditory cortex, is still not fully understood.

Our lab aims to uncover how neuronal circuits enable the brain to make sense of sounds. We adopt a systems neuroscience approach, combining advanced techniques such as optogenetics, in vivo electrophysiology (both extracellular and patch-clamp recordings), functional imaging (including voltage-sensitive dye and two-photon calcium imaging), behavioral assays, cochlear and cortical implants, and computational modeling. Using these tools, we explore the functions of neuronal circuits in the mouse central auditory system.

Our ongoing research projects are directed toward:

Characterizing the juvenile development of auditory responses to sounds of increasing complexity. We investigate how auditory responses to complex sounds develop during early life. Our work focuses on identifying critical periods for these sounds and uncovering the factors that regulate developmental plasticity. In parallel, we assess the behavioral consequences of manipulating specific cortical circuits during development, and examine how auditory cortical activity relates to perception and decision-making. Our findings provide new insights into how the brain processes various sound features during development and reveal which cortical circuits are engaged by specific auditory features. By characterizing the plasticity of the auditory cortex, this research may ultimately contribute to new treatments for restoring normal auditory processing in adults with hearing impairments.

Defining the development basis of categorization. Categorization—the ability to group sensory inputs into meaningful classes—is fundamental to perception. It allows us, for example, to understand words spoken with different accents or to recognize individual instruments within an orchestra. While categorization has been extensively studied in adults, much less is known about when and how categories emerge during development. Are they innate, or do they form through experience? We hypothesize that the heightened plasticity of the juvenile brain plays a key role in the emergence and stability of categories. Our research examines how perceptual categorization and neural processing evolve during adolescence, and how these changes impact prediction, learning, and memory.

Unravelling the neural mechanisms that facilitate learning through progressively complex tasks. Throughout history, effective learning strategies have been designed to optimize skill acquisition. One powerful strategy is Curriculum Learning (CL), where tasks are learned sequentially, starting from simpler ones and progressing to more complex challenges. This approach, widely used in both education and machine learning, enables learners to build on prior knowledge to master more difficult tasks. Despite its success, the neural mechanisms underlying curriculum learning remain largely unexplored. In this project, we investigate these mechanisms by developing a novel auditory discrimination paradigm in mice, systematically studying how behavioral and neural processes adapt as task complexity increases.

Exploring new pathways to hearing restoration through cortical implants. Although cochlear implants have revolutionized hearing restoration, they have important limitations, including reduced spectral resolution, limited acoustic detail, and ineffectiveness in patients with auditory nerve damage. This project explores whether cortical implants might offer a more effective alternative. Our preliminary findings show that cortical stimulation enables better auditory discrimination performance across various tasks compared to cochlear stimulation, albeit with a longer learning phase. Remarkably, mice trained with natural sounds could seamlessly switch to cortical stimulation and vice versa, without requiring retraining—suggesting that cortical implants can evoke percepts closely resembling natural hearing. Brain activity patterns recorded in response to all three input types support these behavioral findings. </span>

Exploring the functions of neuronal circuits in the central auditory system