Assessment of functional brain activation using a NIRS/EEG multimodal system

Wednesday, October 26, 2011 — Poster Session III
10:00 a.m. – Noon	Natcher Conference Center	NICHD	IMAG-27

Authors

• L Najafizadeh
• J Kainerstorfer
• A Medvedev
• F Amyot
• J Riley
• A Gandjbakhche

Abstract

Functional near-infrared spectroscopy (fNIRS) is a non-invasive technique, which employs light to measure the local changes in oxyhemoglobin and deoxyhemoglobin concentrations associated with brain activity. Combining NIRS with Electroencephalography (EEG) in a multi-modal imaging setting, would allow us to correlate the brain hemodynamic response (from NIRS) to neuronal activity (from EEG) and gain better understanding of the brain functionality. As the most reported neuropsychological damages from TBI patients are in the domains of memory, attention, and executive functioning, two tasks that engage subjects in working memory (N-back) and complexity judgment activities, were implemented. A NIRS system, with optical probes placed on the frontopolar and left and right lateral frontal areas, was combined with a 128-channel EEG system. Changes in hemoglobin concentrations in conjunction with EEG data identify the areas involved in performing each task. The N-back task shows strong activations in right frontopolar region. Captured activations for the second task, were in anterior-inferior part of the left lateral frontal cortex, and the frontopolar area, which reflects language- and assessment-related activities, respectively. This study demonstrates the capabilities of optical imaging technique in providing information not only on spatial localization but also on interregional interactions during cognitive processes.

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