We caught a glimpse of a symbol becoming an idea in the brain.

Science News shares results from an English MRI experiment that has mapped, for the first time, how exactly our brain takes a symbol, like a letter, and converts it into the thought of a spoken sound inside the brain:

As readers associate symbols with pronunciation and part of a word, a pecking order of brain areas processes the information, the researchers report August 19 in the Proceedings of the National Academy of Sciences. The finding unveils some of the mystery behind how the brain learns to tie visual cues with language.

Over two weeks, the scientists taught made-up words written in two unfamiliar, archaic scripts to 24 native English–speaking adults. The words were assigned the meanings of common nouns, such as lemon or truck. Then the researchers used functional MRI scans to track which tiny chunks of brain in that region became active when participants were shown the words learned in training.

The way letters look — curves or staunch lines — takes hold in the back of the ventral occipitotemporal cortex, the team found. But when sounds and meanings come into play, an area further forward in that brain region that better handles abstract concepts seemed to kick into gear.

Words in the two scripts that had similar pronunciations or meanings triggered similar brain activity, the team found.

PNAS paper is here.