When we’re told “This coffee is hot” upon being served a familiar caffeinated beverage at our local diner or cafe, the message is clear. But what about when we’re told “This coffee is not hot”? Does that mean we think it’s cold? Or room temperature? Or just warm?
A team of scientists has now identified how our brains work to process phrases that include negation (i.e., “not”), revealing that it mitigates rather than inverts meaning—in other words, in our minds, negation merely reduces the temperature of our coffee and does not make it “cold.”
“We now have a firmer sense of how negation operates as we try to make sense of the phrases we process,” explains Arianna Zuanazzi, a postdoctoral fellow in New York University’s Department of Psychology at the time of the study and the lead author of the paper, which appears in the journal PLOS Biology. “In identifying that negation serves as a mitigator of adjectives—‘bad’ or ‘good,’ ‘sad’ or ‘happy,’ and ‘cold’ or ‘hot’—we also have a better understanding of how the brain functions to interpret subtle changes in meaning.”
In an array of communications, ranging from advertising to legal filings, negation is often used intentionally to mask a clear understanding of a phrase. In addition, large language models in AI tools have difficulty interpreting passages containing negation. The researchers say that their results show how humans process such phrases while also potentially pointing to ways to understand and improve AI functionality.
While the ability of human language to generate novel or complex meanings through the combination of words has long been known, how this process occurs is not well understood.
To address this, Zuanazzi and her colleagues conducted a series of experiments to measure how participants interpreted phrases and also monitored participants’ brain activity during these tasks—in order to precisely gauge related neurological function.
