Fronto-temporal mapping and connectivity using NIRS for language-related paradigms

NIRS studies were performed on 15 normal right-handed adults to understand the hemodynamic response of the fronto-temporal cortex in response to language paradigms. A 32-channel NIRS system (Imagent ISS Inc.) was used to perform NIRS studies in response to word expression and word reception language paradigms. Activation, functional connectivity, and lateralization analyses were carried out and correlated across all subjects and for each paradigm/stimuli. It was observed that Broca's region plays a major role and Wernicke's region plays a supporting role when responding to word expression paradigm (as observed in past NIRS studies). On the contrary, it is the right homolog of Wernicke's (and partly right homolog of Broca's region) that plays a major role during word reception of comprehensible text (as observed from fMRI studies). This is the first NIRS study that images the entire fronto-temporal regions to understand language from various analyses, towards future work in epileptic/schizophrenic populations. (C) 2012 Elsevier Ltd. All rights reserved.