A construct developed in the work of Jörg Zinken. Discourse metaphors emerge in discourse and are conventionally tied to a particular linguistic form. That is, they are explicitly claimed not to be motivated by an underlying conceptual metaphor. In this, the theoretical account of discourse-based metaphors can be seen as standing in opposition to the orthodoxy of conceptual metaphor theory and represents a usage-based model of metaphor. Discourse metaphors are associated with particular communicative needs and may often be polemical, dying out when the communicative need they serve is no longer required or relevant. For instance, the discourse metaphor Frankenfood was applied to food based on genetically modified crops in European public discourse during the 1990s. The purpose of the metaphor, employed initially in publications by the Friends of the Earth organization, was to stigmatise GM-based foods by associating them with the Frankenstein frame, relating to an abhorrent man-made creation which led to unforeseen and disastrous consequences.