3. Study 2: product preference investigation 3.1. Materials and methods
3.1.1. Products
The stimuli were the same as those used in Study 1 and the preparation protocol was also identical.
3.1.2. Subjects
Subjects were recruited from the same pools as in Study 1. A total of 208 subjects (94 males, 114 females; 16–59 years old, average age 27.2 years old, median 22 years old) participated in this research. They were students, staff, friends and family at the
University of California in Davis.