TACTILE INSENSITIVITY

The term tactile insensitivity is indebted to the Latin verbtangere, which means to touch. It was introduced in or shortly before 1995 by the American psychologists Arien Mack (b. 1931) and Irvin Rock (1922-1995) to denote a failure to consciously perceive an above-threshold tactile stimulus, due to the fact that the observer's focus of attention is elsewhere. A typical setting in which tactile insensitivity can occur is a distraction task, i.e. a setting where a test person is asked to identify a certain tactile stimulus (such as the drawing of a letter B on the forearm), and is simultaneously presented with an unexpected, and quite different tactile stimulus (such as a drop of water falling on the other arm). The phenomenon itself has been described in the medico-psychological literature at least since the era of mesmerism. In the 19th-century hypnotist tradition, inattentiveness constitutes one of the explanatory models for the mediation of * negative hallucinations. It has also been suggested that tactile insensitivity may be related in a conceptual and phenomenological sense to hypnotically induced * analgesia, and * anaesthesia. A related phenomenon, which may occur in the visual modality, is called * inattentional blindness. When occurring in the auditory modality, the term * inattentional deafness is used. Yet another related phenomenon is * change blindness.

Mack, A., Rock, I. (1998).Inattentionalblindness. Cambridge, MA: MIT Press. Parish, E. (1897).Hallucinations and illusions. A study ofthe fallacies ofperception. London: Walter Scott.