25 March 2015

After Learning New Words, Brain Sees Them As Pictures

When we look at a known word, our brain sees it like a picture, not a group of letters needing to be processed. That's the finding from a Georgetown University Medical Center (GUMC) study which shows the brain learns words quickly by tuning neurons to respond to a complete word, not parts of it. Neurons respond differently to real words, such as turf, than to nonsense words, such as turt, showing that a small area of the brain is holistically tuned to recognize complete words. People are not recognizing words by quickly spelling them out or identifying parts of words, as some researchers have suggested. Instead, neurons in a small brain area remember how the whole word looks—using what could be called a visual dictionary.

This small area in the brain is found in the left side of the visual cortex, opposite from the fusiform face area on the right side, which remembers how faces look. One area is selective for a whole face, allowing us to quickly recognize people, and the other is selective for a whole word, which helps us read quickly. The study asked 25 adult participants to learn a set of 150 nonsense words. The brain plasticity associated with learning was investigated with fMRI-rapid adaptation, both before and after training. The investigators found that the visual word form area changed as the participants learned the nonsense words. Before training the neurons responded like the training words were nonsense words, but after training the neurons responded to the learned words like they were real words.

More information: