Gilman Hall, Johns Hopkins University

The man is catching a fish.

The men is catches fish.

New research from Johns Hopkins University suggests that while writing is a relatively new human invention that evolved from spoken language, “the two brain systems are now so independent that someone who can’t speak a grammatically correct sentence aloud may be able to write it flawlessly.” Or visa versa.

Brenda Rapp, a professor of cognitive science at Johns Hopkins says, “We don’t expect that we would produce different words in speech and writing. It’s as though there were two quasi-independent language systems in the brain.”

What this means to people who understand and study the brain–and what writers staring at lined notebooks and laptop screens have known all along–is that you can’t always write what you’re perfectly able to say.

This has huge implications for patients who have suffered strokes or serious brain trauma, but it could also reshape the way we approach education–particularly students with written-language deficits. The abstract from Rapp’s study “Modality and Morphology: What We Write May Not Be What We Say” in Psychological Science considers the following:

Written language is an evolutionarily recent human invention; consequently, its neural substrates cannot be determined by the genetic code. How, then, does the brain incorporate skills of this type? One possibility is that written language is dependent on evolutionarily older skills, such as spoken language; another is that dedicated substrates develop with expertise. If written language does depend on spoken language, then acquired deficits of spoken and written language should necessarily co-occur. Alternatively, if at least some substrates are dedicated to written language, such deficits may doubly dissociate. We report on 5 individuals with aphasia, documenting a double dissociation in which the production of affixes (e.g., the -ing in jumping) is disrupted in writing but not speaking or vice versa. The findings reveal that written- and spoken-language systems are considerably independent from the standpoint of morpho-orthographic operations. Understanding this independence of the orthographic system in adults has implications for the education and rehabilitation of people with written-language deficits.