"...Interpreted loosely, the idea is that those with ADHD are chronically understimulated by both their environment and their internal cognitive representations, leading them to search almost incessantly for more stimulating things (environments or thoughts), which takes the behavioral form of distractibility. This chronic cognitive understimulation might be overcome by introducing additional noise to the cognitive system through the perceptual system." http://scienceblogs.com/developingintelligence/2007/09/21/when-noise-helps-stochastic-re-1/ I find this kind of research somewhat dangerous, since one proposed "cure" can ellicit a totally different response to the cure itself. For example, over-stimulation from random noise can lead to anxiety. The brain is probably the most adaptive system known, and I wonder on the viability of these studies.