Optical topography with near-infrared spectroscopy during a verbal-fluency task

In this study we investigated the changes in brain oxygenation in 22 subjects during a verbal fluency task (VFT) using multichannel near-infrared spectroscopy (NIRS). To assess topographical effects in more detail we measured over bilateral prefrontal and over the left frontolateral cortex in I I subjects. We found significantly higher increases in O2HB, as a sign of cerebral activation, during the VFT compared to a verbal repetition control task over the left prefrontal and the inferior left lateral brain areas. These results underscore the value of NIRS to assess functional brain activation during cognitive tasks. Furthermore, it shows the advantage of multichannel compared to previously used single channel NIRS measurements.