Alternative-reinforcer magnitude effects on resurgence across successive relapse tests in mice.

Alternative-reinforcement-based treatments are common strategies for reducing maladaptive behavior in humans. When conditions of alternative reinforcement are made worse in some way, however, behavior that was targeted for elimination may resurge. Previous research using rat subjects has demonstrated that high-magnitude (relative to low-magnitude) alternative reinforcement produces faster elimination of target behavior but more resurgence once removed. The purpose of the present experiment was to assess cross-species generality of these effects to mice. During Phase 1, lever pressing produced single food pellet reinforcers. Next, during Phase 2, lever pressing was extinguished and groups of mice experienced either small-magnitude (one pellet), large-magnitude (three pellet), or no alternative reinforcement for nose poking. All food was suspended in Phase 3 to assess resurgence. As an additional goal of this study, changes in resurgence across successive determinations were assessed by cycling between periods during which alternative reinforcement was present or absent. Large-magnitude alternative reinforcers produced faster suppression of target behavior but more resurgence when removed than did small-magnitude alternative reinforcers. Moreover, this effect endured across repeated resurgence tests.