Attention deficit/hyperactivity disorder (ADHD) is one of the most common childhood psychiatric disorders. Its symptoms involve patterns of inattention, hyperactivity, and impulsivity, which are associated with global, social, academic, and adaptive impairment; need for treatment increases with each additional symptom. Children with ADHD commonly experience sleep problems, which add to difficul...

This article explores the widely reported finding that the subjective duration of a stimulus is positively related to its magnitude. In Experiments 1 and 2 we show that, for both auditory and visual stimuli, the effect of stimulus magnitude on the perception of duration depends upon the background: Against a high intensity background, weak stimuli are judged to last longer. In Experiment 3 we s...

The multimode dynamics of vertical-cavity surfaceemitting lasers with different active-region diameters was measured under subnanosecond electrical excitation (800-ps pulse duration, 100-ps risetime). The dynamics is characterized by the delayed onset of higher order modes which have a turn-on delay that is dependent on the active-region diameter and the excitation parameters. A simple model th...