Analysis of brain activity respond to vibration comfort on horizontal vibration using near-infrared spectroscopy

Abstract

Ride comfort is an important issue in improving passenger comfort in an automobile. Quantifying ride comfort is difficult because it affects a person's emotions and physiology. In this paper, we measure brain activities using near-infrared spectroscopy to clarify the features of brain activities while sensing vibration. Hopefully, the results obtained in this study can be applied to quantify subjective evaluation for ride comfort. Moreover, we measured brain activities while sensing vibrations which are uncomfortable and not uncomfortable vibrations. Uncomfortable and not uncomfortable vibrations were determined on the basis of sensory evaluation. Results showed that the concentration of oxygenated hemoglobin (oxy-Hb) levels in the prefrontal cortex change with the sense of vibration. In addition, during uncomfortable vibration, the oxy-Hb level declined more than that while sensing not uncomfortable vibrations. In addition, we measured brain activities while sensing a vibration which is divided over subject's feeling to the vibration and found that oxy-Hb of the subjects sensing uncomfortable vibration declined in the prefrontal cortex. Therefore, we infer that decline of oxy-Hb in the prefrontal cortex is relative to an uncomfortable feeling.