Assessment of impulsivity and the development of self-control in students with attention deficit hyperactivity disorder.
We examined a combined approach of manipulating reinforcer dimensions and delay fading to promote the development of self-control with 3 students diagnosed with attention deficit hyperactivity disorder. First, we administered a brief computer-based assessment to determine the relative influence of reinforcer rate (R), reinforcer quality (Q), reinforcer immediacy (I), and effort (E) on the students' choices between concurrently presented math problems. During each session, one of these dimensions was placed in direct competition with another dimension (e.g., RvI involving math problem alternatives associated with high-rate delayed reinforcement vs. low-rate immediate reinforcement), with all possible pairs of dimensions presented across the six assessment conditions (RvQ, RvI, RvE, QvI, QvE, IvE). The assessment revealed that the choices of all 3 students were most influenced by immediacy of reinforcement, reflecting impulsivity. We then implemented a self-control training procedure in which reinforcer immediacy competed with another influential dimension (RvI or Qvl), and the delay associated with the higher rate or quality reinforcer alternative was progressively increased. The students allocated the majority of their time to the math problem alternatives yielding more frequent (high-rate) or preferred (high-quality) reinforcement despite delays of up to 24 hr. Subsequent readministration of portions of the assessment showed that self-control transferred across untrained dimensions of reinforcement.