Pain and<unk>  have very different behavioral response patterns. Pain elicits a withdrawal reflex, which leads to retraction and therefore a reaction trying to protect an endangered part of the body.<unk>  in contrast creates a scratch reflex, which draws one to the affected skin site.<unk>  generates stimulus of a foreign object underneath or upon the skin and also the urge to remove it. For example, responding to a local<unk>  sensation is an effective way to remove insects from one's skin. Scratching has traditionally been regarded as a way to relieve oneself by reducing the annoying<unk>  sensation. However, there are hedonic aspects to scratching, as one would find noxious scratching highly pleasurable. This can be problematic with chronic<unk>  patients, such as ones with atopic dermatitis, who may scratch affected spots until they no longer produce a pleasant or painful sensation, instead of when the<unk>  sensation disappears. It has been hypothesized that motivational aspects of scratching include the frontal brain areas of reward and decision making. These aspects might therefore contribute to the compulsive nature of<unk>  and scratching. Contagious<unk>  Events of "contagious<unk> " are very common occurrences. Even a discussion on the topic of<unk>  can give one the desire to scratch.<unk>  is likely to be more than a localized phenomenon in the place one scratches. Results from a study showed that<unk> ing and scratching were induced purely by visual stimuli in a public lecture on<unk> ing. The sensation of pain can also be induced in a similar fashion, often by listening to a description of an injury, or viewing an injury itself. There is little detailed data on central activation for contagious<unk> ing, but it is hypothesized that a human mirror neuron system exists in which one imitates certain motor actions when they view others performing the same action. A similar hypothesis has been used to explain the cause of contagious yawning.<unk>  inhibition due to pain Studies done in the last decade have shown that<unk>  can be inhibited by many other forms of painful stimuli, such as noxious heat, physical rubbing/scratching, noxious chemicals, and electric shock.
Itch
Pain
Rape
Sound 
Body odor
Sharsheret 
Face
Position 