The activation of modality-specific representations during discourse processing

Previous research has shown that readers generate mental images of events. Most studies have investigated imagery during the reading of short texts, which also included explicit judgment tasks. In two fMRI studies, we assessed whether modality-specific imagery occurs during naturalistic, discourse comprehension. We identified clauses in the texts that elicited auditory, motor, or visual imagery. In both studies, reading motor imagery clauses was associated with increases in activity in left postcentral and precentral sulci, and reading auditory imagery clauses was associated with increases in left superior temporal gyrus and perisylvian language-related regions. Study 2 compared presentation of connected discourse to a condition in which unconnected sentences were presented, preventing the establishment of global coherence. Sensorimotor imagery was strongest when readers were able to generate a globally coherent discourse representation. Overall, these results suggest that modality-specific imagery occurs during discourse comprehension and it is dependent on the development of discourse-level representations.