The brain processes fact and possibility differently

By Sarah MooreReviewed by Emily Henderson, B.Sc.Dec 4 2020

NYU researchers have ascertained that our brains process information perceived factual differently to that perceived as possible. In a paper published this month in eNeuro, the distinct neural responses to language conveying fact and possibility are highlighted.

Image Credit: Tulling et al., eNeuro 2020

This research will likely be important in the road to gaining a deeper understanding of how our brains determine what is real and what is a possibility, it also has implications for how word choice impacts our beliefs and cognitive processing.

Facts induce greater brain activity

Assistant professor Ailís Cournane of NYU's Department of Linguistics teamed up with Ryan Law, an expert on the development of modal expressions in children and researcher at the NYU Abu Dhabi Institute, along with others, to investigate how the brain processes language inferring fact and possibility.

In today’s current climate, this research is particularly relevant, given the era of disinformation and fake news. We are at a time when critical thinking is key, where our brains are making decisions on the validity of information daily. Revealing exactly how the brain processes this information is key to understanding how word choice can direct impact subconscious processing.

Language is believed to be unique to humans. It is an immensely powerful communication tool that allows for the efficient transference of information and abstract ideas. Scientists have long understood that the way information is delivered to us has an impact on how the brain processes it. The paper’s lead author and doctoral candidate in NYU's Department of Linguistics, Maxime Tulling, explains that “Our brains seem to be particularly sensitive to information that is presented as fact, underlining the power of factual language.”

Of course, this makes sense in evolutionary terms. Giving greater importance to factual information allows us to react to things that are real and may need immediate responses to keep us safe. Indeed, this is what the study found, that factual information elicits stronger brain activity in comparison to uncertain information.

To come to this conclusion, the scientists designed a study to measure how the brain responds to different kinds of language. The researchers aimed to determine how the brain processes possibilities as conveyed by so-called "modal" words like "may" and “might”. To do this, the team devised numerous experiments using formal semantic theories.

In each of these experiments, participants’ brain activity was recorded by magnetoencephalography (MEG) while they listened to various sentences expressed in two ways, as factual, e.g. "Knights carry large swords, so the squires do too”, and possible, e.g. "If knights carry large swords, the squires do too”.

The study's results demonstrated that when presented with the factual sentences, the brain’s neural activity rapidly increased. This reflected an enhanced engagement in phrases that were positioned as fact rather than a possibility.

Also, the researchers were able to determine the distinct brain areas involved in processing fact versus fiction. The data collected by MEG reveals that when updating the representation of the beliefs of a character in a story, the right temporoparietal areas were activated. When updating one's own beliefs, the frontal medial areas showed increased activity.

The neural correlates of separating fact from fiction

Our brains, it seems, are wired to focus on facts.

Brain regions involved in processing discourse rapidly differentiated facts from possibilities, responding much more robustly to factual statements than to non-factual ones. These findings suggest that the human brain has a powerful, perspective-adjusted neural representation of factual information and, interestingly, much weaker, more elusive cortical signals reflecting the computation of mere possibilities.”

Pylkkanen

The study’s findings show that the brain responds specifically to information that is presented as fact. It also highlighted the brain regions involved in distinguishing factual from non-factual language.