Idahomom: it is entirely possible for a child to display signs of both over sensitivities and under responsiveness to sensory information. It is referred to as a modulation disorder. Modulation refers to the ability to notice and respond to relevant sensory information in an manner appropriate to the situation. People with modulation disorders have difficulty selectively attending to sensory information (ie: filtering irrelevant info out, attending to what is meaningful) and even more difficulty responding to it appropriately (reactions seem out of proportion to the intensity of the stimulus). What's worse is that the same sensory input can at one time be aversive and then the next time not even noticed. Very frustrating for everyone, especially the person whose system never knows what to expect in terms of sensory input. People can also just have hypersensitivities to certain input (like sound) and hyposensitivities to other input (like vision or vestibular input).

It certainly sounds like your son is highly sensitive and responds to sensory input, but also to the emotional content of situations. Using sensory strategies can help a lot to manage the stress in life, whether there is a "disorder" or not. Google for "sensory diets" and you'll find good info on how to use sensory tools for calming and relaxation. The Alert Program is a great way to teach the concept, but is geared for kids ages 8 -12. It can be adapted though (www.thealertprogram.com)

But it sounds like your son might benefit from some help in learning how to cope with those emotional stressors during the day. I don't really have any handy resources for that. My DS7 is the same way at times, getting overloaded by his reaction to events of the day, not really the sensory experiences per se, but more of the Emotional OEs kicking in. Perhaps some GT resources about OEs might have some help there. Check out the SENG website for articles (www.sengifted.org) on emotional health for gifties.

There's a lot of overlap with OEs and SI disorders. A lot of confusion as to what constitutes a disorder and what is just individual differences. The book "Living Sensationally: Understanding Your Senses" by Winnie Dunn is a great resource for just learning how sensory processing affects all of us differently and uniquely. Each nervous system truly is unique, some just have more difficulty with certain processing than others.

HTH some more!