A new study has found that domestic dogs process components of speech preferentially and similarly to humans, supporting claims that dogs really can be a ‘man’s best friend’.
Published in 'Current Biology', the UK study analysed the response to human speech in more than 250 dogs, finding evidence that domestic dogs, who have been exposed to human speech, use different hemispheres of the brain to process the verbal and emotional aspects of our words.
Just as humans detect the intonations and characteristics of our voice and speech, domesticated canines are also capable of processing speaker related information such as the personality and emotions encoded in our speech.
This study extended previous research which revealed that dogs understand our intent to communicate information, picking up on verbal cues and eye contact.
And while domesticated dogs don’t necessarily understand the words being said, they are capable of understanding not only who we are, how we say things but what we say.
Co-researcher of the University of Sussex study, Victoria Ratcliffe said the results showed dogs processing both verbal and speaker-related information in different areas of the brain, similarly to humans.
"Previous studies have shown that other mammals also have hemispheric biases when processing their own species’ vocalisations, but no one had ever looked at whether biases existed in domesticated animals in response to the different components of human speech," she said.
Researchers exposed canines to simultaneous sounds of human speech on both sides of the dog to identify which half of the brain was processing the information. If the dog turned left, it indicated the information was being processed by the right hemisphere and vice versa.
The left hemisphere of the brain is typically used to process verbal contents of the speech and the right hemisphere interprets the characteristics of the voice and emotional contents of the speech.
The results of the study found domesticated dogs demonstrate significant hemispheric bias when interpreting human speech.
When exposed to a familiar command or meaningful speech, the dogs were more likely to turn to the right, indicating a left-hemispheric preference.
If the same command was in a foreign language or speaker-related vocals cues were exaggerated, the reverse bias was observed.
"Although we cannot say how much or in what way dogs understand information in speech from our study, we can say that dogs react to both verbal and speaker-related information and that these components appear to be processed in different areas of the dog's brain," Ms Ratcliffe said.
