Fig 5. The effect, averaged across rats, of the first reinforcer in sequences up to eight reinforcers on three interreinforcer measures following the sequence: log₂ behavior ratio (diamonds); log₂ first postreinforcer visit length (squares); log₂ average postchangeover visit length at the not-first-reinforced lever of the component (triangles).

The effect was calculated by taking the difference in a measure following two sequences identical except for the first reinforcer (first-reinforced lever in a component vs. not-first-reinforced) and averaging across all sequences of the same length. Error bars represent standard deviations across rats.