Brain activity during cooperative work determined by simultaneous fNIRS measurement in two people and the effect of different social skills on cooperative task performance

The primary goal of our research is to investigate brain functions during Human-Human cooperative work. To this end, the following tasks were performed: 1) A Human-Human system to investigate cooperative work was developed. 2) Blood flow changes in two brains were examined using functional near-infrared spectroscopy (fNIRS) during a cooperative task. 3) On the basis of brain activity, we evaluated the effect of social skills on performance of the cooperative task, a simultaneous tapping task carried out by two people. In our experimental system, one person moved their finger rhythmically in synchronization with the finger movements of another person. We evaluated their social skills using the KiSS-18 questionnaire. We focused on the inferior frontal gyrus (IFG) and superior frontal gyrus (SFG) as regions of interest (ROI) based on the results of a previous study on Human-Machine system. In addition, we conducted an experiment on listening to sound and found cerebral blood flow changes in the IFG. Our results demonstrated that the cerebral blood flow changes of two people have a positive correlation in the IFG and negative one in the SFG. We suggest that sound may affect brain activity in the IFG and SFG, which are regions related to cooperation between people. Moreover, we found that the same level of social skills leads to a good performance in cooperative work as measured by the tapping score in the cooperative task.