It means that certain neural mechanisms involved in the acquisition of human language may not be so uniquely human after all…

Have you ever told your dog an entire story and casually dropped the word “eat” or “out” in between? There is a good chance that your four-legged friend suddenly looked at you with pricked ears. In that entire stream of words, your dog has recognized that word that is particularly loaded for him. It means that your dog has learned where a particular word in a verbiage begins and where the word ends. And that’s prettier than you might think.

Babies

Human babies are known to be able to recognize individual words in a stream of words long before they learn what those exact words mean. To determine where a word ends and the next begins, babies unconsciously make complex calculations to distinguish so-called syllable patterns. In this way, they learn that syllables that often occur together form probable words. Researchers now have in a new study discovered that dogs can also recognize such complex, regularities in speech.

Learn to recognize patterns

Keeping track of patterns is not by definition unique to humans. Many animals possess the ability to recognize such regularities. This is also known as ‘statistical learning’. “In addition, we also know that some animals, particularly primates and songbirds, can learn quite complex regularities,” study researcher Marianna Boros said. Scientias.nl. “But this is the first time a non-human mammal has applied it to language, which requires very complex calculations.”

Extract words from a stream of words

To learn new words from a word stream, it is not enough to count how often certain syllables occur together. It is much more efficient to calculate how likely it is that those syllables occur together. This is exactly how people, even eight-month-old babies, approach the seemingly difficult task of word segmentation; they calculate the probability that one syllable follows another. “Until now, we didn’t know if any other mammal also uses such complex calculations to recognize words from word streams,” Boros said.

How do dogs process speech?

However, according to the researchers, it is very important to study how mammals, especially dogs, process speech. Dogs are the earliest domesticated species and probably the one we talk to most often. Yet we know very little about the neural processes underlying their ability to learn words. And that while “it can teach us a lot about the processes that led to the emergence of human specialization for speech perception,” Boros says. “It can be particularly useful to identify skills that are innate in dogs, for example, but only emerged during their domestication.”

EEG

To find out what happens in dogs’ brains when they listen to speech, the researchers measured brain electrical activity using EEG. And that leads to an interesting discovery. The researchers saw differences in dogs’ brain waves when they uttered frequent or rare words. But, even more surprisingly, the team also noticed differences in brain waves for syllables that always occur together compared to syllables that only occasionally occur in succession. So it seems that dogs not only make simple calculations (the number of times a word occurs), but are also capable of complex calculations (the probability that the syllables of a word occur together). And that’s interesting. Because this is exactly the kind of complex statistic that human babies use to recognize words from word streams.

Brain areas

To investigate how similar the brain regions responsible for this complex computational capacity in dogs are to those in humans, the dogs were also studied using MRI. And that also leads to a surprising discovery. “We know that humans are able to learn languages ​​thanks to special brain regions in the auditory cortex,” Boros says. “In principle, these are specialized in language processing from birth. Now we see that in the speech processing of dogs, this auditory cortex is also involved. This is a very specialized area, not a general processing area.”

Unique to humans

The findings have far-reaching implications. For we are now beginning to understand more and more that certain neurological processes involved in the acquisition of human language may not be so uniquely human after all. “The results prove that a distant mammalian species, the dog, has very similar neural mechanisms for the statistical learning of speech,” Boros concluded. “So it’s possible that the mechanisms involved in word learning were already present in the first mammals, or in the last common ancestor of dogs and humans.”

There is still plenty to decipher. Because at the moment it is still unclear exactly how these human-analogue brain mechanisms for learning words in dogs arose. Do they reflect skills that dogs have developed by living in a language-rich environment, during thousands of years of domestication, or do they represent an ancient capacity of mammals? “We don’t know at this point whether only dogs have the ability to apply complex calculations to extract individual words from word streams, or whether it’s a general ‘mammal ability’,” Boros says. “But speech is relevant to dogs because they have to deal with it every day. In addition, they also understand many human communicative acts, so it is possible that they have developed more efficient mechanisms for processing speech than other species. This will have to be tested extensively in the future.”