Summary: A new study reveals that the orbitofrontal cortex (OFC) plays a crucial role in adapting the auditory cortex to different listening contexts, which could provide insights into treating sensory impairment disorders.
Takeaways:
- OFC’s Role in Hearing Adaptation: The study found that the OFC helps the auditory cortex adapt to changing listening contexts, enhancing the brain’s ability to switch between passive and active listening.
- Implications for Sensory Disorders: Understanding how the brain adjusts hearing sensitivity can lead to better treatments for neurodevelopmental disorders like autism, dyslexia, and schizophrenia, where sensory regulation is often disrupted.
- Potential Human Applications: Although conducted on gerbils, the findings suggest that improving the connection between the OFC and the auditory cortex could enhance hearing abilities and help develop better strategies for those with sensory impairments.
A new study from the University of Maryland (UMD) study reveals how the brain adapts hearing in different listening situations, potentially offering insights into human sensory impairment disorders.
Using an animal model, UMD researchers found that the orbitofrontal cortex (OFC), a brain region associated with decision-making but not typically linked to hearing, plays a central role in helping the auditory cortex (a primary hearing center of the brain) adapt to changing contexts or situations. The team’s findings were published in the journal Current Biology.
“Our hearing doesn’t just depend on the sounds around us. It also relies heavily on what we’re doing and what’s important to us at that moment,” says UMD Biology Assistant Professor Melissa Caras, the paper’s senior author. “Understanding the neural mechanisms responsible for these adjustments can also lead to a better understanding of and potential treatments for neurodevelopmental disorders like autism, dyslexia or schizophrenia—conditions where sensory regulation goes awry.”
Examining the Brain’s Hearing Process
To closely examine the brain circuitry involved in the hearing process, the researchers turned to gerbils, small mammals whose basic hearing system is similar to that of humans. The animals were exposed to sound patterns in two different contexts. In one context, the animals listened to sounds passively without needing to do anything. In the other, the animals had to perform a specific action in response to the sounds they heard. By recording and manipulating the brain activity of the animals, the team discovered that the OFC helped the animals switch between passive and active listening.
“In short, the OFC sends signals to the auditory cortex when it’s time to pay closer attention to sounds,” Caras says. “It’s not certain whether the signals are sent directly or indirectly via an intermediary brain region, but we do know that activity in the OFC is essential to how the gerbils behaved in our experiments.”
When the OFC was silenced, the animals’ auditory cortex did not switch between passive and active listening, impairing their ability to pay attention to and react to a behaviorally relevant sound.
Further reading: Hearing Loss is Associated with Subtle Brain Changes
“In terms of a more human-oriented analogy, it would be as if I told you to suddenly pay attention to your refrigerator humming in the background,” Caras explained. “If your OFC was silenced and unable to send a signal to your auditory cortex, you might have difficulty doing so because the ability to rapidly alter your sound perception would be impaired.”
While this study was conducted in animals, Caras says the findings may have notable implications for human health and well-being. The ability to quickly shift attention to important sounds is essential for many day-to-day activities including communicating with others and navigating busy or dangerous environments.
“We’re just beginning to understand how the brain fine tunes hearing sensitivity in response to sudden shifts in behavioral contexts. We plan to explore exactly how the OFC communicates with the auditory cortex and see whether it’s possible to strengthen the connection and improve hearing ability,” Caras says. “This work is paving the way for researchers and health care professionals to develop better strategies for improving hearing in both healthy individuals and those with sensory impairments.”
Featured image: Image of a brain with the orbitofrontal cortex lit up in green. Photo: Melissa Caras
