The role of visual representations during the lexical access of spoken words

• We examine the temporal role of visual cortices in lexical access of speech.
• We contrasted word imageability and word frequency effects on cortical activation.
• Word imageability modulated visual cortices early in recognition.
• Word frequency modulated posterior temporal gyrus activation later in recognition.
• Sensory aspects of a lexical item are not a consequence of lexical activation.

Do visual representations contribute to spoken word recognition? We examine, using MEG, the effects of sublexical and lexical variables at superior temporal (ST) areas and the posterior middle temporal gyrus (pMTG) compared with that of word imageability at visual cortices. Embodied accounts predict early modulation of visual areas by imageability – concurrently with or prior to modulation of pMTG by lexical variables. Participants responded to speech stimuli varying continuously in imageability during lexical decision with simultaneous MEG recording. We employed the linguistic variables in a new type of correlational time course analysis to assess trial-by-trial activation in occipital, ST, and pMTG regions of interest (ROIs). The linguistic variables modulated the ROIs during different time windows. Critically, visual regions reflected an imageability effect prior to effects of lexicality on pMTG. This surprising effect supports a view on which sensory aspects of a lexical item are not a consequence of lexical activation.