V. Noreika et al., “Timing Deficits in Attention-Deficit / Hyperactivity Disorder (ADHD): Evidence from Neurocognitive and Neuroimaging Studies,” Neuropsychologia 51 (2013): 235; A. Pine et al., “Dopamine, Time, and Impulsivity in Humans,” J Nsci 30 (2010): 8888; W. Schultz, “Potential Vulnerabilities of Neuronal Reward, Risk, and Decision Mechanisms to Addictive Drugs,” Neuron 69 (2011): 603.