Fig 2. Overall observing rates (top three panels) separated by multiple schedule component (middle three panels), and food key response rates (bottom three panels) during the final six sessions of the conditions of Experiment 2.

Dissociated response rates are shown only for the first four conditions. The condition headings refer to the DRO value in effect for the tandem FR 1 DRO x schedule of conditioned reinforcement. The heading EXT refers to the condition during which the observing contingency was removed. The filled circles denote response rates during the VI component of the multiple VI Ext schedule, and empty circles denote response rates during the Ext component. The data for dissociated rates of observing (middle) and food key (top) responding were lost for the fifth session in the first condition for Pigeon 114.