Reasoning and other mental operations are believed to rely onmental models. Arguments have been made that mental mod-els share representational substrate with perception. Here, wedemonstrate that a neural dynamic architecture that perceptu-ally grounds language may also support the building of men-tal models. Supplied with a sequence of simple premises thatspecify the colors of object pairs as well as their spatial rela-tion, the architecture builds a mental model of the describedscene. We show how the neural processes of the architec-ture evolve in response to both determinate and indeterminatepremises. For indeterminate premises, we demonstrate thatthe preferred mental models observed in human participantsemerge from the underlying neural dynamics.