Highly Sensitive People may indeed be just that, according to a recent study. Sensory Integration Disorders have been defined as dysfunctions of the body's sensory systems. This would seem to include autism spectrum disorders and some genetic disorders. It could also include attention deficit disorders.
"Our understanding of sensory processing sensitivities and disorders has taken a leap forward in the past few years though the field is still messy because people come to the topic from so many different disciplines and viewpoints. Aron's work described 'SPS' or Sensory Perception Sensitivity, a personality trait only partly associated with introversion or emotionality."
Using the Aron's HSP (Highly Sensitive People) Questionaire, the study shows that such people have not only more brain activation, but also have higher sensitivity to visual detail. They are vulnerable to greater sensory input than the average person, and are more affected by this input. But while they may be overloaded by this sensory awareness, they also may benefit from this greater awareness as well.