چکیده (انگلیسی):

Abstract: Placebo effect has been applied in multiple aspects and the different components of placebo effect have already been studied in many different researches. Taste, which is one of the physiological effects, is a vital component of the placebo effect, and according to a Chinese idiom, "bitter taste medicines are more effective", bitter tastes comes into play. However, bitter placebo does not work for everyone because of cultural difference and taste preferences. Results from factorial ANOVA showed there was a significant interaction effect of the taste of the drink and the type of personality on cognitive test performance when it came to speakers of different languages: native English and non-native English speaking participants. Also, bitter placebo only works for supertasters who have experience of the aversion of bitterness and agree that bitter drinks can keep themselves healthy. Hence, supertaster participants who feel gross after tasting the bitter drink will persuade themselves the benefit of the placebo. For future studies, it should modify the methods with a self-rated scale of the placebo taste and a different placebo substance with a universal flavor for improvement.