April 2, 2013
California Sea Lion Learns To Keep The Beat
April Flowers for redOrbit.com - Your Universe Online
The first empirical evidence of an animal not capable of vocal mimicry that can keep the beat comes from a California sea lion that bobs her head in time to music.The findings of this study, published online in the Journal of Comparative Psychology, challenge current scientific theories, according to the authors. Those theories hold the ability to synchronize movements with sound is associated with the same brain mechanisms that allow for vocal mimicry in humans and some birds such as cockatoos, parrots and budgerigars.
"Understanding the cognitive capabilities of animals requires carefully controlled, well-designed experiments," said Colleen Reichmuth, PhD, with the Institute of Marine Sciences at the University of California at Santa Cruz. "This study is particularly rigorous because it examines, step-by-step, the learning conditions that supported the emergence of this complex behavior."
In six experiments led by candidate Peter Cook at the Long Marine Lab at UCSC, Ronan, a three-year-old sea lion, demonstrated her ability to bob her head to the beat.
[ Watch the Video: Beat Keeping in a California Sea Lion ]
"Dancing is universal among humans, and until recently, it was thought to be unique to humans as well," said Cook. "When some species of birds were found to have a similar capability for rhythmic movement, it was linked to their ability to mimic sound. Now we're seeing that even mammals with limited vocal ability can move in time with a beat over a broad range of sounds and tempos."
A simplified section of John Fogerty's "Down on the Corner" was the backbeat for Ronan's first dance lesson. Once she was trained to bob her head to music, Ronan was tested with two pop songs. Without any prior exposure to the songs, "Everybody" by the Backstreet Boys, and "Boogie Wonderland" by Earth, Wind and Fire, Ronan was able to bob to the beat of both over a course of multiple trials. She then followed along to the five different tempos of "Boogie Wonderland."
Over the course of the trials, Ronan's skills markedly improved and endured beyond the end of the experiment. The research team gave Ronan a follow-up test a few weeks following the final experiment. Maintaining a minimum of 60 bobs to each of the various beats, she was successful at keeping the beat with each of the sounds previously used.
According to the study, Cook originally trained Ronan to move in time to hand signals. This was replaced by a simple non-musical sound signal. Ronan was rewarded with a fish each time she successfully completed tests by bobbing her head in time to various rhythmic sounds.
To verify Ronan was actually responding to the rhythm, the researchers varied the types and speeds of sounds. They tested her with two computer generated metronome-like tick noises to rule out the possibility she was bobbing her head in response to the previous beat. One of the metronome ticks kept the beat and one missed the beat. Ronan kept the beat going even when the metronome missed the beat.