Editing Microexpression (section)

==Types==
Microexpressions are typically classified based on how an expression is modified. They exist in three groups:
*'''Simulated expressions''': when a microexpression is not accompanied by a genuine emotion. This is the most commonly studied form of microexpression because of its nature. It occurs when there is a brief flash of an expression, and then returns to a neutral state.<ref name="cse.usf.edu">{{cite web |url=http://www.cse.usf.edu/~mshreve/publications/FG11.pdf |title=Archived copy |access-date=2013-11-17 |archive-url=https://web.archive.org/web/20131216022610/http://www.cse.usf.edu/~mshreve/publications/FG11.pdf |archive-date=2013-12-16 |url-status=dead }}</ref>
* '''Neutralized expressions''': when a genuine expression is [[expressive suppression|suppressed]] and the face remains neutral. This type of micro-expression is not observable due to the successful suppression of it by a person.<ref name="cse.usf.edu"/>
*'''Masked expressions''': when a genuine expression is completely masked by a falsified expression. Masked expressions are microexpressions that are intended to be hidden, either subconsciously or consciously.<ref>{{cite thesis|last=Godavarthy|first=Sridhar|title=Microexpression spotting in video using optical strain|url=http://scholarcommons.usf.edu/etd/1642|type=MS thesis |publisher=University of South Florida |date=July 2010|accessdate=15 June 2011}}</ref>