Environmental Stimulation Does Not Reduce Impulsive Choice in ADHD: A "Pink Noise" Study.

OBJECTIVE The preference for sooner smaller over larger later rewards is a prominent manifestation of impulsivity in ADHD. According to the State Regulation Deficit (SRD) model, this impulsive choice is the result of impaired regulation of arousal level and can be alleviated by adding environmental stimulation to increase levels of arousal. METHOD To test this prediction, we studied the effects of adding background "pink noise" on impulsive choice using a classical and new adjusting choice delay task in a sample of 25 children with ADHD and 28 controls. RESULTS Children with ADHD made more impulsive choices than controls. Adding noise did not reduce impulsive choice in ADHD. CONCLUSION The findings add to the existing evidence on impulsive choice in ADHD, but no evidence is found for the SRD model's explanation of this behavioral style. Alternative explanations for impulsive choice in ADHD are discussed.