Auditory perception and physiology laboratory
​The goal of the Anbuhl Laboratory is to understand the neural circuits that support auditory perceptual and cognitive skills, and determine how developmental hearing loss can alter those circuits. This work integrates both sensory and cognitive processing, enabling a better understanding of the underlying mechanisms that contribute to sensory and cognitive disorders.
Neural basis for listening effort
Having a conversation in a quiet or noisy place can take a certain amount of mental energy to engage successfully. But for those with hearing loss, even if they have hearing aids or other hearing devices, it can take significantly more listening effort to do so, causing long-term negative consequences on quality of life (Morata et al., 2005; Alhanbali et al., 2017). In fact, there is considerable evidence that sensory disorders across the lifetime, including hearing loss, can impair cognitive demands of this sort (Lin et al., 2013; Moore et al., 2020). Yet, it is uncertain how the brain engages in listening effort, and importantly, how hearing loss is involved. Our goal is to identify the neural circuits that support listening effort during auditory perceptual tasks, and explore how hearing loss alters this circuit.
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Auditory Effort behavioral task. This is one approach to adjust the amount of effort required on an auditory perceptual task. Here, task difficulty is varied by presenting long (Easy) or brief (Hard) sound durations. Anbuhl et al., 2023 (BioRxiv)
Adolescent vulnerability to sensory deprivation
While the vast majority of developmental plasticity studies have focused on brief bouts of sensory deprivation during early critical periods, we know that anatomical and functional properties of the central nervous system, as well as some perceptual skills and learning, have a prolonged period of maturation that extends well into adolescence (Banai et al., 2011; Huyck et al., 2011; Zadeh et al., 2019). However, the same neural attributes that allow us to become sensory experts also pose a risk for negative environmental factors that may disrupt behavioral maturation. While these risks are well-established prior to sexual maturity (i.e., critical periods), the degree of neural vulnerability during adolescence remained uncertain.
Here, we induced transient hearing loss spanning adolescence in gerbils, and asked whether behavioral and neural maturation were disrupted. We found that adolescent hearing loss caused a significant perceptual deficit that could be attributed to degraded auditory cortex processing, as assessed with wireless single neuron recordings and within-session population-level analyses. Finally, auditory cortex brain slices from adolescent hearing loss animals revealed synaptic deficits that were distinct from those typically observed after critical period deprivation. Taken together, these results showed that diminished adolescent sensory experience can cause long-lasting behavioral deficits that originate, in part, from a dysfunctional cortical circuit.
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Anbuhl et al., 2022 (Nature Communications)
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Development of auditory-cognitive circuits
The transition from childhood to adulthood is characterized by prolonged development of auditory perceptual learning, executive function, and other cognitive skills including attention and working memory in humans. Using anatomical, electrophysiological, and behavioral approaches, our lab will explore the developmental time course of cortical regions that support auditory perceptual and cognitive skills.
Impact of adolescent hearing loss on auditory-cognitive circuits
Adolescent hearing loss is associated with deficits in perceptual function in rodents (Anbuhl et al., 2022). In humans, hearing loss in adolescence also contributes to alterations in cognitive function, including elevated listening effort. Yet, it is unclear how adolescent hearing loss alters the underlying neural circuitry. Our goal is to determine how adolescent hearing loss impacts neural pathways that contribute to auditory-cognitive skills, including its role in the central mechanisms of listening effort.
Hearing loss approach. We use earplugs (EPs) to induce a reversible mild-moderate hearing loss during adolescent ages in the gerbil.
We will use awake-behaving electrophysiological approaches to explore how hearing loss alters cortical neurons during behavior.
