MONDAY, Jan. 10, 2005 (HealthDayNews) -- If you want to be like Dr. Dolittle and talk to the animals, it might help to know that rats can tell the difference between languages.
Spanish researchers found that rats were able to use rhythm and intonation speech cues to distinguish between spoken Dutch and Japanese. This makes rats only the third type of mammal -- along with humans and Tamarin monkeys -- who have been shown to possess the ability to recognize different speech patterns.
First, different groups of rats were trained to press a lever and receive a reward when they heard a five-second sentence in either Dutch or Japanese. All the rats were then exposed to both languages. The rats who'd been exposed to Japanese responded only to that language and the rats who'd been exposed to Dutch responded only to Dutch.
Further tests revealed the rats were able to identify new Dutch or Japanese sentences they'd never heard before.
However, the rats did have some trouble identifying the languages when different people spoke the same sentences that had previously been recognized by the rats.
"It was striking to find that rats can track certain information that seems to be so important in language development in humans," study author Juan Toro said in a prepared statement. The research shows "which abilities that humans use for language are shared with other animals, and which are uniquely human. It also suggests what sort of evolutionary precursors language might have."
The findings appear in the January issue of the Journal of Experimental Psychology: Animal Behavior Processes.
More information
The American Speech-Language-Hearing Association has more about speech and language.
