Detecting Mental Calculation Related Frontal Cortex Oxygenation Changes for Brain Computer Interface Using Multi-Channel Functional Near Infrared Topography

Multi-channel functional near infrared topography (fNIRT) is a non-harmful, non-invasive and safe optical imaging technique that allows the simultaneous acquisition of oxygenated and deoxygenated hemoglobin concentration changes on the scalp. This study was aimed at investigating the potential use of fNIRT in association with a cognitive system, namely the working memory, for brain-computer interface (BCI). By using a 8-channel fNIRT system (NIRO-200 with multi-fiber adapter, Hamamatsu Photonics), we demonstrated in eight subjects that the mental calculation provokes over the frontal cortical region a significant increase in oxygenated hemoglobin and a concomitant smaller and delayed significant decrease in deoxygenated hemoglobin in all measurements points of both hemispheres. This result indicates that cortical regions involved in higher cognitive functions may serve as a readily self-controllable input for BCI fNIRT based applications.