A new study has found that dogs do not understand the differences between the words, which differ in a phoneme, despite their exceptional auditory ability. This study has been done by Hungarian scientists from the Eotvos Lorand University of Budapest (ELTE). Scientists have mapped the brain activities of conscious dogs using non-invasive electroencephalography (EEG). They have said that it might be the reason why dogs can learn a very low number of words in their lifetime. The findings of the study have been released in the journal Royal Society Open Science. Experts have said that dogs can differentiate human speech sounds such as ‘d’, ‘o’, and ‘g’. They have said that humans and dogs have many similarities in their neuronal processing of words. Despite these similarities, dogs can learn only a limited number of words in their life even if they are raised by a human family and are in close proximity to human speech. The lead author of the study and other experts have found that dogs are not competent enough to attend to all differences in speech sounds.
Experts have conducted a test on untrained dogs to map their brain activities. Electroencephalography (EEG) is a usual procedure, which is used in human clinical and research studies. They have invited untrained dogs along with their owners. The owners along with their dogs have been asked to relax and get their pets familiarized with the experiment. After some time, scientists have put electrodes on the dogs’ heads and tightened them with tape. Experts made these dogs hear some familiar instructional words like ‘sit’ and some absurd words with different sounds like ‘sut’ through a tape recorder. The analysis of recorded brain activity has found that the brains of the dogs have been able to distinguish known words from unknown absurd words from 200 milliseconds after the starting of the words. A similar study on humans has shown that humans react differently to important words and absurd words within a few hundred milliseconds. However, the brains of the dogs have not been able to differentiate between meaningful words and absurd words, which have differed in single speech sound only.
Scientists have said that this pattern has been more similar to the findings of the same study with human infants who have been around 14 months. As per the data, infants become efficient in recognizing phonetic details of the words within 14 to 20 months, however, experts have seen in experimental and word learning tests, that younger human infants are not able to process phonetic difference of the words despite the fact they are able to distinguish speech sounds within weeks after birth. Experts believe that there is a similarity in human infants’ brain activity and dogs’ brain activity for instruction words, they are aware of. The brain activity of human infants and dogs shows attentional and processing biases for absurd words, which they are not familiar with. Nevertheless, further research is required to substantiate whether this is the reason why dogs cannot get a hold of a significant vocabulary.