Spontaneous Micro-Facial Expressions: Classical Studies and New Horizons

Abstract

Emotional facial expressions are one of the main sources of human non-verbal communication. At the same time, emotions are transmitted through facial expressions both consciously and unconsciously. In particular, micro-facial expressions and background facial expressions of low intensity are those that are poorly amenable to conscious control. According to many studies, micro-facial expressions can be considered a window into a person’s true feelings. However, due to their fleetingness and low intensity, micro expressions are very difficult to catch with the naked eye. This article presents an overview of scientific knowledge about human micro-facial expressions, starting from the discovery to the current level of development. We consider the history of studying the topic and describe in detail the current state of the art. We further discuss the limitations and presents ideas on the prospects for further studies of micro-facial expressions, taking into account the cross-cultural component.