Bioethics Blogs

Vision Loss Boosts Auditory Perception

Image of green specks with blobs of blue centered around a large red blob with tentacles

Caption: A neuron (red) in the auditory cortex of a mouse brain receives input from axons projecting from the thalamus (green). Also shown are the nuclei (blue) of other cells.
Credit: Emily Petrus, Johns Hopkins University, Baltimore

Many people with vision loss—including such gifted musicians as the late Doc Watson (my favorite guitar picker), Stevie Wonder, Andrea Bocelli, and the Blind Boys of Alabama—are thought to have supersensitive hearing. They are often much better at discriminating pitch, locating the origin of sounds, and hearing softer tones than people who can see. Now, a new animal study suggests that even a relatively brief period of simulated blindness may have the power to enhance hearing among those with normal vision.

In the study, NIH-funded researchers at the University of Maryland in College Park, and Johns Hopkins University in Baltimore, found that when they kept adult mice in complete darkness for one week, the animals’ ability to hear significantly improved [1]. What’s more, when they examined the animals’ brains, the researchers detected changes in the connections among neurons in the part of the brain where sound is processed, the auditory cortex.

The new findings are surprising because such drastic changes in neural wiring were generally thought to occur only during a critical window of development in early childhood. That’s why children are such quick learners. As we age, the brain becomes less plastic, which means it’s less adaptable and less capable of remodeling neural connections. But this new study suggests we may have underestimated the brain’s ability to adapt in adulthood.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.