Mental models are minds representations of fictive or real situations. Idea that mind uses “small-scale models” to perceive reality was first introduced by Kenneth Craik in 1943 and the idea was further developed by Phil Johnson-Laird during 1980s.
Ih his book “Mental Models” Johnson-Laird claims that “it is now plausible to suppose that mental models play a central and unifying role in representing objects, states of affairs, sequences of events, the way the world is, and the social and psychological actions of daily life”.
Mental models are simplified representations, constantly changing and typically include wrong assumptions or contradictions.