Cortical and Subcortical Correlates of Ororhythmic Behaviors

Abstract

Although the healthy adult possesses a large repertoire of coordinative strategies for oromotor behaviors, a range of nonverbal, speech-like movements including cyclic jaw motion and lip pursing can be observed during speech. The extent of overlap among sensorimotor speech and nonspeech central neural correlates is unknown. The purpose of this study was to determine the spatial extent of unique and shared neural bases subserving task- and rate-specific ororhythmic behaviors utilizing a randomized block design fMRI study with an audiovisual motor stimulus paradigm to record neural correlates of suck and unvoiced syllabic speech performed at 1 or 3 Hz by a group of healthy adults. A functionally defined region of interest analysis provided (1) descriptive analysis of individual clusters, and (2) quantitative analysis of the extent of activation differences between conditions. Both factors (task and rate) were shown to significantly affect BOLD signal changes at the cortical, subcortical, and brainstem levels.