Touch

Touch is an important sensory modality because its receptors spread over the whole body. Touch is also, among the senses, the first modality to work as soon as the fetal period. In this entry, two forms of touch are considered: the somesthetic system, or passive touch, is limited to the cutaneous stimulation of a nonmoving limb, and a simple sensation of caress is felt; active touch is used to examine space and objects mainly with hands. In this case, voluntary sequential movements are necessary (kinesthetic modality). The association of these two modalities is called the haptic mode. The deformations of the muscles, joints, and tendons resulting from exploratory movements are added to cutaneous perceptions. Because the exploratory movements are sequential, the integration and synthesis of ...