EFFECT OF HANDEDNESS ON RESPONSE INHIBITION: FMRI STUDY

Response inhibition one of the crucial cognitive functions in humans. Neuroimaging studies revealed the critical role of the right presupplementary motor area and the right anterior cingulate cortex in response inhibition. These data were obtained mostly on right-handers; however, lateralization of this function could be related to manual lateral asymmetry in humans. We compared brain areas involved in simple response inhibition tasks performance (rings and letters were used as visual stimuli) and differences in the activated brain structures between groups of participants with different types of motor asymmetry by fMRI. 29 participants (23 right-handers and 6 left-handers) performed Go/NoGo task and Stop-signal task. In Go/NoGo task the participants had to ignore specific non-verbal stimuli (red rings). In Stop-signal task the participants had to ignore specific verbal stimuli (red letters). Results showed increased activation of the right cerebellar hemisphere only for right-handers in comparison with left-handers in Stop-signal task. Within-group analysis in the left-handers group revealed activation of the fusiform gyrus and the BA19 during Go/NoGo task in comparison with Stop-signal task. Significant differences have been demonstrated between right-handers and left-handers in simple response inhibition tasks which involve verbal stimuli processing. The right cerebellum structures have been activated during verbal information processing in right-handers in Stop-signal-task. (C) 2017 Published by Future Academy www.FutureAcademy.org.UK