Our memories and imagination may make nouns the most mentally demanding part of speech
Some things are hard to say, but according to an easily quantifiable metric, “I’m sorry” and “I love you” are easy. While there may be emotional difficulties and sharing one’s feelings, none of those words are all that difficult, because non of them are common nouns. A study of human speech across nine languages from around the world has found that all humans are most likely to show a bit of cognitive strain when trying to say the names of specific nouns more than any other part of speech. In a weird way, the issue might come down to our brain’s attempt to familiarize ourselves with what we’re saying before we say it.
The study analyzed recorded conversations from Mexico, Siberia, the Himalayas, the Amazon and the Kalahari Desert. While the specific grammar and vocabulary of these languages obviously differed, a commonality turned out to be how much people hesitate before saying a noun in the middle of a sentence. No matter if someone paused silently or with an “uh” or “um,” they were 60 percent more likely to take an extra moment before saying a noun than a verb. Even difficult or unfamiliar verbs weren’t this likely to require a pause, suggesting that there was something about how a noun is handled in the brain that makes us take an extra moment.
Stopping to see what we’re saying
Researchers suspect that these pauses may be due to our brains trying to conceptualize nouns as we try to say them. When we think of something, our brain brings that information into our working memory, often “seeing” it in our mind’s eye. So when we say “dog,” our brain will give us at least an abstract image of a dog, and that moment of internal observation may cost us enough time that we will need to break the rhythm of a spoken statement. As further evidence of the extra effort nouns require, researchers point out that we often avoid restating actual nouns in spoken conversation, replacing them with pronouns like “it” and “that” as much as possible. Verbs apparently aren’t so taxing, as we they don’t cause us to pause, even if we have to keep explicitly using a verb over and over.
Some of this may be eventually confirmed by observing the brain activity of people during casual conversations, looking at how much one’s own speech activates your memory and visual cortex. The fact that these patterns were so widespread suggests that a pattern will turn up though. Having analyzed over 288,848 words in nine languages, researchers are confident that these pre-noun pauses are something universal to human cognition, rather than weird tics of a specific culture’s customs or grammar.
Source: Why You Say 'Um' Before Certain Words by Mindy Weisberger, Live Science