Our daily interactions with people or\u00a0situations are defined by our expressions, predominantly facial.\u00a0Our expressions are determined by our internal learning process,\u00a0which would have evolved uniquely for each individual, thereby\u00a0contributing to unique expressions for varying situations. For\u00a0example, if an emotion of surprise is elicited, the person\u2019s\u00a0reaction could be surprise with a hint of anger or surprise with a\u00a0hint of a smile. The response to stimulus, thus, is unique per\u00a0individual, at times including a combination of subtle expressions.<\/p>\n
A limiting factor to emotion elicitation is that not all individuals\u00a0are expressive about their emotions, and are often able to hide\u00a0some of the key expressions at will. However, this will not\u00a0prevent them from exhibiting some minimal expression that\u00a0denotes a person\u2019s emotion at that instant of time. This is referred\u00a0to as a micro expression, which typically lasts for a fraction of a\u00a0second and can uniquely represent a person\u2019s emotion [1].<\/p>\n