**4.2 Relationship with WTP**

Many studies have suggested that WTP judgments are based on activation in the medial OFC. Because this area is not on the brain surface, it is difficult to monitor this activation with NIRS. We have shown that brain activation in the right superior frontal and the left and right parietal lobes was related to WTU. Because of the limitations of NIRS measurements, it is unclear whether the medial OFC was activated in the current experiments and related to WTU judgments.

#### **4.3 Difference by race**

Participants with different nationalities and different cultural backgrounds are expected to have different styles of thinking. A number of studies have suggested that people from different cultures have different cognitive processing styles (e.g., North Americans attend to focal objects more than do East Asians). Although these cultural differences may cause the correlations between brain activations and subjective ratings to differ among cultures, our results indicate the operation of a common brain mechanism in this regard. However, culture may nonetheless influence impressions, WTU, WTB, and brain activation related to these judgments. The cultural differences involved in-store shopping behaviors need to be understood given that such differences carry important implications for both academic and commercial domains.

#### **4.4 Advantage of NIRS for studying everyday situations**

The participants in the current study moved their arms and hands to apply a facial cream and touched jar. These actions are not permitted in magnetic resonance imaging scanners, and they also cause strong electroencephalogram artifacts due to muscle potentials. Thus, brain monitoring with NIRS is the only acceptable technique to use in situations in which participants move with relative freedom.
