Structural and functional peculiarities of speech system organization in right-handed subjects revealed using functional magnetic resonance imaging. The co-dominant right hemisphere

Nowadays a lot of mechanisms of brain speech processes organization are poorly studied.Functional magnetic resonance imaging (fMRI) gives an opportunity to non-invasive study subdominant right hemisphere speech organization of right-handers' language function.With the help of our proposed three paradigms we studied in particular speech prosody in healthy volunteers.The first paradigm was aimed at identifying the of sentence intonation characteristics, the second-the definition of accentuated and unaccentuated rhythms and the third-tune recognition.When processing the data, we observed activation of both classical areas of verbal representations, dominated in terms of volume and intensity in the right hemisphere of the brain, and secondary and tertiary areas, in particular supplementary motor area, Brodmann area 6, 9, and the field of Brodmann 46 during testing of the third paradigm.We also noted activation of the cerebellum, the limbic system, and deep subcortical structures of the brain.The results of this study confirm the prevalence of verbal representations in both hemispheres of the brain that allows us to speak about hemispheres co-dominance for this function.These paradigms fully comply with stated objectives and can be used for mapping of prosodic speech characteristics in humans.