Effects of the duration of expressions on the recognition of microexpressions

Objective： The purpose of this study was to investigate the effects of the duration of expressions on the recognition of microexpressions, which are closely related to deception. Methods： In two experiments, participants were briefly （from 20 to 300 ms） shown one of six basic expressions and then were asked to identify the expression. Results： The results showed that the participants＇ performance in recognition of microexpressions increased with the duration of the expressions, reaching a turning point at 200 ms before levelling off. The results also indicated that practice could improve the participants＇ performance. Conclusions： The results of this study suggest that the proper upper limit of the duration of microexpressions might be around 1/5 of a second and confirmed that the ability to recognize microexpressions can be enhanced with practice.