YOU鈥橰E just so right-side. The left hemisphere of our brains seems to tune into the phonemes in speech that combine to form words, and the right hemisphere focuses on the rhythm and intonation of words, which can carry emotional information. Animals may do the same when processing sounds of their own species, and perhaps even when hearing humans speak.
To test whether domestic dogs have learned to process human speech as we do, and at the University of Sussex in Falmer, UK, placed 25 dogs between two speakers. They played them snippets of speech, such as the command 鈥渃ome on then鈥� (Current Biology, ). The assumption, based on previous research, was that an animal primarily using the left hemisphere to process a sound will turn its head to the right, and vice versa.
When a command was delivered in a flat emotionless tone, 80 per cent of the dogs turned their heads to the right, suggesting they were concentrating on the words, not the emotion. If the commands were said in an emotional tone but some consonants were removed to make the words unintelligible, most of the dogs turned to the left. This suggests that dogs, like us, process different components of human speech in different parts of the brain.
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Ratcliffe and Reby鈥檚 work suggests that dogs have learned to recognise a handful of human words that carry meaning. So a dog really does listen to its master鈥檚 voice.
鈥淚t would be extremely exciting to see the neural background of these orienting asymmetries,鈥� says Attila Andics of the E枚tv枚s Lor谩nd University in Budapest, Hungary, who is running functional MRI brain experiments in dogs to probe this further.
This article appeared in print under the headline 鈥淒ogs really do understand what you say鈥�
