A new study has uncovered new information about the way whales and dolphins use sound.
The research — conducted by scientists from the Woods Hole Oceanographic Institution, New College of Florida, UC Berkeley and Oxford University — sheds light and improves our understanding of how these animals use echolocation and how the mechanism works in their brains.
The researchers applied new techniques to map the excised brains of dead cetaceans. This allowed them to better understand the auditory pathways different animals use. The mapping included a comparison between dolphins and a non-echolocating whale called a sei whale.
Commenting on the findings, Sophie Flem, a student in the inaugural class of New College of Florida’s Marine Mammal Master’s program and lead author:
“Our research sought to understand how the pathways for auditory information differed between echolocating and non-echolocating whales. In humans, primates, rodents, and dogs, we have well established maps of what parts of the brain contribute to what kind of processing. We don’t yet have those in dolphin brains, which are strikingly unusual compared to terrestrial animal brains.”
While senior author Peter Cook, an associate professor of marine mammal science at New College of Florida added:
“Comparative neurobiologists have longed to examine the patterns of connections within dolphin and whale brains for years, believing that the unique evolutionary history of these species will provide new insights into how brains evolve. The technology is finally there to start to crack open these mysterious nervous systems and find out how they tick.”
Cook added:
“it’s believed that neural control of vocal output has totally shifted in dolphins as they evolved their unique nasal vocal apparatus. We can now map out vocal control in dolphins, and how it differs from baleen whales. Both groups of animals have the rare ability to learn new vocal behavior, and dolphin vocal systems are some of the strangest in the animal kingdom. Now that we can opportunistically and ethically look inside these animals’ brains, they’re just getting started teaching us.”
Peter Tyack, emeritus research scholar in biology at WHOI and a co-author on the study said:
“While neuroscientists used to think of the cerebellum largely as a center for balance and motor (muscle/movement) control, newer evidence strongly suggests that it serves as an integration center for sensory and motor information, and, importantly, a rapid prediction center. Dolphins use echolocation to interact with their world, and, unlike hearing and vision, they must produce the energy that then returns to their sensory receptors – echolocation is part hearing and part vocalization. Think about moving your hand to produce the touch sense feedback that lets you find the light switch, similarly, dolphins move around their echolocation beam to get the feedback they need to function in a dark, underwater environment.”
You can find the original research published in PLOS One here.
