John Pilley and Alliston Reid of Wofford College demonstrated their dog, Chaser, learned the names of 1,022 objects in the three years of the study. They stopped training after three years due to their time constraints, not because the dog could not learn more names. The dog appears to have no upper limit, the researchers say.
Chaser's ability to learn and remember more than 1,000 proper nouns reveals clear evidence of several capacities necessary for learning receptive human language: the ability to discriminate between 1,022 different sounds representing names of objects, the ability to discriminate many objects visually, an extensive vocabulary and a substantial memory, the researchers say.
"This research demonstrates that dogs, like children, can develop extensive vocabularies and understand that certain words represent individual objects and other words represent categories of objects, independent in meaning of what one is asked to do with those objects," the study authors say in a statement.
The findings are published in the journal Behavioural Processes.