Published on November 16th, 2012 | by Simi0
Do Dolphins Think Nonlinearly?
A new study suggests this may be the case.
Dolphins may use complex nonlinear maths when hunting, according to a new study that suggests they could be far more skilled than was ever thought possible before reports ABC Science.
Inspiration for the new study, published in the latest Proceedings of the Royal Society, came after lead author Tim Leighton watched an episode of the Discovery Channel’s Blue Planet series and saw dolphins blowing multiple tiny bubbles around prey as they hunted.
“I immediately got hooked, because I knew that no man-made sonar would be able to operate in such bubble water,” says Leighton, a professor of ultrasonics and underwater acoustics at the University of Southampton.
“These dolphins were either ‘blinding’ their most spectacular sensory apparatus when hunting – which would be odd, though they still have sight to reply on – or they have a sonar that can do what human sonar cannot …Perhaps they have something amazing,” he adds.
Leighton and colleagues Paul White and student Gim Hwa Chua set out to determine what the amazing ability might be.
They started by modelling the types of echolocation pulses that dolphins emit. The researchers processed them using nonlinear mathematics instead of the standard way of processing sonar returns. The technique worked, and could explain how dolphins achieve hunting success with bubbles.
The math involved is complex. Essentially it relies upon sending out pulses that vary in amplitude. The first may have a value of 1 while the second is 1/3 that amplitude.
“So, provided the dolphin remembers what the ratios of the two pulses were, and can multiply the second echo by that and add the echoes together, it can make the fish ‘visible’ to its sonar,” says Leighton. “This is detection enhancement.”
Leighton, T. G., Chua, G.H. and White, P.R. (2012) Do dolphins benefit from nonlinear mathematics when processing their sonar returns? Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences, 468, 3517-3532.[subscribe2]