Stimulus Control Revisited

Activities change as context changes. Stimuli are the context of activities. If activities are under control of stimuli, their frequency or likelihood changes as stimuli change. To speak of stimulus control is to speak of activities changing as their context changes. Traditionally, a process of response strengthening explains that organisms work for contact to or avoidance of important events (unconditioned reinforcers/punishers) or signals, which predict them (conditioned reinforcers/ punishers). I present data from an experiment on verbal behavior supporting an alternative approach in which “reinforcers” are performance modulators. All behavior may be partly attributed to selection during phylogeny and partly during ontogeny. In this approach, changes in performance do not reflect strengthening of responses in a reserve but are an innate response to experienced predictive relations between important events and their signals or signposts. The predictive value of signals, rather than strengthening, explains the allocation of time to different activities.