New evidence indicates that dogs may possess the ability to mentally 'picture' objects, akin to humans. When a dog responds to commands or retrieves an object, it's often unclear what exactly goes on inside its mind. Do dogs comprehend and react to tone of voice, the structure of words, accompanying gestures, or simply the context? While behavioral studies have provided some insights, recent research provides further evidence suggesting that our beloved canine companions indeed grasp the meaning conveyed by words.
A study published on March 22 in the journal Current Biology reveals that dogs exhibit neural activity patterns suggesting they can differentiate between words representing different objects. Moreover, they seem surprised when presented with words and objects that do not correspond. A team of neuroscientists and animal behavior researchers conducted non-invasive electroencephalogram (EEG) tests on 27 pet dogs to measure the electrical activity in their brains during experiments involving their owners and familiar toys. They identified an electrical impulse pattern reminiscent of a known signal in humans, shedding light on canine cognition and contributing to our understanding of the origins of complex language.
"We were interested in whether dogs understand words the way humans do," stated one of the co-authors, Lilla Magyari, a cognitive neuroscientist and psychologist at the University of Stavanger in Norway.
Ellen Lau, a neuroscientist specializing in linguistics at the University of Maryland, commented on the significance of employing EEG in studying dogs, highlighting its ability to facilitate direct comparisons between humans and other animals.
Dogs, as household pets, offer a unique opportunity for studying language experience due to their close interaction with humans, according to Amritha Mallikarjun, a neuroscientist researching canine cognition at the University of Pennsylvania.
The researchers aimed to determine if dogs comprehend the association between words and corresponding objects, even those without exceptional abilities. They adapted a cognitive test, previously used in infant studies, to assess dogs' responses to words and objects.
In the experiment, dogs and their owners were separated by an electronic window, with electrodes attached to the dogs' heads. The dogs were played recordings of their owners' voices calling attention to familiar objects while being shown their owners' faces. Subsequently, the window revealed either a matching or mismatched object, while the EEG recorded brain activity.
Out of 27 dogs initially involved, 18 were included in the final analysis. The EEG readings consistently displayed significant signal peaks when a mismatch occurred between the auditory stimulus and the presented object, suggesting dogs can distinguish between the meanings of certain words.
The researchers found that the timing of the pulse could be analogous to the human N400 signal, although further research is needed to confirm this hypothesis.
Colin Phillips, a linguistics professor at the University of Oxford and the University of Maryland, noted that the study does not demonstrate dogs' ability to generalize words to entire categories of objects. Nonetheless, he acknowledged the careful design of the study and its contribution to understanding canine cognition.
The study authors emphasize that dogs' linguistic abilities are not comparable to humans', but offer insights into the evolutionary origins of language and the complexities of communication across species. Understanding the communicative abilities of animals can provide valuable insights into human cognition and language development, while also highlighting the unique abilities of different species.