Contextual control of slot-machine gambling: replication and extension.

Participants were trained and tested to select stimuli of differing physical quantities in the presence of 2 color contextual cues for more than and less than. Following more than and less than relational training, participants allocated the majority of their responses to the slot machine that shared formal properties of color with the contextual cue for more than, despite the identical payout probabilities of the slot machines.