Lip-readers ‘hear’ silent words

Lip-readers’ minds seem to “hear” the words their eyes see being formed. And the better a person is at lip-reading, the more neural activity there is in the brain’s auditory cortex, scientists reported recently at the annual meeting of the Cognitive Neuroscience Society.

Earlier studies have found that auditory brain areas are active during lip-reading. But most of those studies focused on small bits of language — simple sentences or even single words, said study co-author Satu Saalasti of Aalto University in Finland.

In contrast, Saalasti and colleagues studied lip-reading in more natural situations. Twenty-nine people read the silent lips of a person who spoke Finnish for eight minutes in a video. “We can all lip-read to some extent,” Saalasti said, and the participants, who had no lip-reading experience, varied widely in their comprehension of the eight-minute story.

In the best lip-readers, activity in the auditory cortex was quite similar to that evoked when the story was read aloud, brain scans revealed. The results suggest that lip-reading success depends on a person’s ability to “hear” the words formed by moving lips, Saalasti said.