Dogs understand what we say AND how we say it: Researchers find canine brains are far more capable than thought
- Dogs, like people, use the left hemisphere to process words
- Right hemisphere brain region is used to process intonation
- Praising activates dog’s reward centre only when both match
A groundbreaking study to investigate how dog brains process speech has revealed canines care about both what we say and how we say it.
It discovered that dogs, like people, use the left hemisphere to process words, and the right hemisphere brain region to process intonation.
It found praise activates dog’s reward centre only when both words and intonation match, according to the new study in Science.
Trained dogs around the fMRI scanner used in the study: Dogs, like people, use the left hemisphere to process words, and the right hemisphere brain region to process intonation, according to the new study in Science.
Researchers also say dogs developed the neural mechanisms to process words much earlier than thought.
‘The human brain not only separately analyzes what we say and how we say it, but also integrates the two types of information, to arrive at a unified meaning.
‘Our findings suggest that dogs can also do all that, and they use very similar brain mechanisms,’ said lead researcher Attila Andics of Department of Ethology and MTA-ELTE Comparative Ethology Research Group at Eötvös Loránd University in Budapest.
Andics and colleagues also found that praise activated dogs’ reward centre – the brain region which responds to all sorts of pleasurable stimuli, like food, sex, being petted, or even nice music in humans.
Importantly, the reward centre was active only when dogs heard praise words in praising intonation.
‘It shows that for dogs, a nice praise can very well work as a reward, but it works best if both words and intonation match.
‘So dogs not only tell apart what we say and how we say it, but they can also combine the two, for a correct interpretation of what those words really meant.
HOW THEY DID IT
Dogs were exposed to recordings of their trainers’ voices as the trainers spoke to them using multiple combinations of vocabulary and intonation, in both praising and neutral ways.
For example, trainers spoke praise words with a praising intonation, praise words with a neutral intonation, neutral words with a praising intonation, and neutral words with neutral intonation.
Researcher Anna Gábor is talking to Barack. Dogs were exposed to recordings of their trainers’ voices as the trainers spoke to them using multiple combinations of vocabulary and intonation, in both praising and neutral ways.
Researchers used fMRI to analyze the dogs’ brain activity as the animals listened to each combination.
Their results reveal that, regardless of intonation, dogs process vocabulary, recognizing each word as distinct, and further, that they do so in a way similar to humans, using the left hemisphere of the brain.
Researchers used fMRI to analyze the dogs’ brain activity as the animals listened to each combination.
Also like humans, the researchers found that dogs process intonation separately from vocabulary, in auditory regions in the right hemisphere of the brain.
Lastly, and also like humans, the team found that the dogs relied on both word meaning and intonation when processing the reward value of utterances.
Barack is lying on the fMRI bed, and inside the machine
‘Again, this is very similar to what human brains do,’ Andics said.
The Hungarian research group shows the capability is not unique to the human brain, the researchers say.
It shows that if an environment is rich in speech, as is the case of family dogs, word meaning representations can arise in the brain, even in a non-primate mammal that is not able to speak.
Researchers used fMRI to analyze the dogs’ brain activity as the animals listened to each combination.
‘During speech processing, there is a well-known distribution of labor in the human brain.
‘It is mainly the left hemisphere’s job to process word meaning, and the right hemisphere’s job to process intonation.
‘We trained thirteen dogs to lay completely motionless in an fMRI brain scanner.
The dogs were trained outside the machine to lie still so the readings could be taken
Dogs are listening to their trainer, Márta Gácsi during the training process for the experiment
‘fMRI provides a non-invasive, harmless way of measurement that dogs enjoy to take part of,’ said Márta Gácsi, ethologist, the developer of the training method, author of the study.
‘We measured dogs’ brain activity as they listened to their trainer’s speech,’ explains Anna Gábor, PhD student, author of the study.
‘Dogs heard praise words in praising intonation, praise words in neutral intonation, and also neutral conjunction words, meaningless to them, in praising and neutral intonations.
‘We looked for brain regions that differentiated between meaningful and meaningless words, or between praising and non-praising intonations.’
Dogs, like people, use the left hemisphere to process words, and the right hemisphere brain region to process intonation, according to the new study in Science.
The brain activation images showed that dogs prefer to use their left hemisphere to process meaningful but not meaningless words.
This left bias was present for weak and strong levels of brain activations as well, and it was independent of intonation.
Dogs activate a right hemisphere brain area to tell apart praising and non-praising intonation.
This was the same auditory brain region that this group of researchers previously found in dogs for processing emotional non-speech sounds from both dogs and humans, suggesting that intonation processing mechanisms are not specific to speech.
Dogs are lying motionless and listening to their trainer during the research.
This study is the first step to understanding how dogs interpret human speech, and these results can also help to make communication and cooperation between dogs and humans even more efficient, the researchers say.
These findings also have important conclusions about humans.
‘Our research sheds new light on the emergence of words mduring language evolution. What makes words uniquely human is not a special neural capacity, but our invention of using them,’ Andics explains.