Dissociating sentential prosody from sentence processing: Activation interacts with task demands

Sentence processing was contrasted with processing of syntactic prosody under two task conditions in order to examine the representation of these components of language and their interaction with working memory load. Twelve adults received fMRI scans while they listened to low-pass filtered and unfiltered sentences either passively, or during tasks that required subjects to remember and recognize information contained in the stimuli. Results indicated that temporal activation for prosodic stimuli differed compared to activation for sentence stimuli only during passive listening tasks. The inclusion of memory demands was associated with frontal activation, which was differentially lateralized for sentence and prosodic stimuli. The results demonstrate differential brain activation for prosodic vs sentential stimuli which interacts with the memory demands placed on the subjects.