Ocular dynamics reveal articulatory processing at single-phoneme level during silent reading

Abstract

Silent reading is a cognitive operation that produces verbal content with no vocal output. One relevant question is the extent to which this verbal content is processed as overt speech in the brain. To address this, we investigated the signatures of articulatory processing during reading. We acquired sound, eye trajectories and vocal gestures during the reading of consonant-consonant-vowel (CCV) pseudowords. We found that the duration of the first fixations on the CCVs during silent reading are correlated to the duration of the transitions between consonants when the CCVs are actually uttered. An articulatory model of the vocal system was implemented to show that consonantal transitions measure the articulatory effort required to produce the CCVs. These results demonstrate that silent reading is modulated by slight articulatory features such as the laryngeal abduction needed to devoice a single consonant or the reshaping of the vocal tract between successive consonants.