Brain imaging of tongue-twister sentence comprehension: twisting the tongue and the brain

This study used fMRI to investigate the neural basis of the tongue-twister effect in a sentence comprehension task. Participants silently read sentences equated for the syntactic structure and the lexical frequency of the constituent words, but differing in the proportion of words that shared similar initial phonemes. The manipulation affected not only the reading times and comprehension performance, but also the amount of activation seen in a number of language-related cortical areas. The effect was not restricted to cortical areas known to be involved in articulatory speech programming or rehearsal processes (the inferior frontal gyrus and anterior insula), but also extended to areas associated with other aspects of language processing (inferior parietal cortex) associated with phonological processing and storage.