Tickling

Abstract: Robert Provine argues in this book that laughter is mostly about relationships, not jokes; that women laugh more at men than vice versa; that speakers laugh more than their audiences; that tickling is a form of tactile communication, not a reflex; and that laughter explains why chimpanzees cannot talk. Among other topics are a history of canned laughter and a description of the laughing epidemic that brought a district of Tanganyika to a standstill in 1962.

Abstract: IN 1933 Blair and Erlanger demonstrated that the recorded spike heights of axone potentials from a phalangeal nerve preparation of the frog varied as their rate of conduction. On the assumption that the intrinsic potential is independent of fibre size the recorded spike heights vary as the diameters squared. Their result offers the possibility of computing the relative rate of axone potentials recorded from sensory nerves in response to various stimuli applied to their receptors. Such a procedure was adopted in some recent investigations on the lingual nerve [Zotterman, 1936]. The present research was started in order to study the response of the thinnest afferent fibres to various stimuli applied to the skin. When records of axone potentials from the thinnest nerve fibres had been obtained attempts were made to measure their rate of conduction directly. This was possible for fibres conducting at rates down to 10 m./ sec. Slower potentials than these, however, could not be measured. Although direct measurements of the slowest rates have not yet been made, the present data concerning the larger fibres provide some fixed points for the correlation of results from different experiments.

Abstract: WHY is it that most people cannot tickle themselves? Darwin observed that “from the fact that a child can hardly tickle itself, or in a much less degree than when tickled by another person, it seems that the precise point to be touched must not be known”1. (There may be differences between man and other primates. The Kelloggs observed that their chimpanzee Gua was “frequently observed in the process of tickling herself and laughing as a result”2.) But this hypothesis seems prima facie incorrect, or at least inadequate, as most children can be tickled even when they know where and when the tickle stimulus is to be applied. No experimental work appears to have been reported on this question, and Darwin's interest was primarily centred on the biological value of ticklishness and laughter. The problem is perhaps not trivial; evidently knowledge of some sort is necessary for the cancellation of the ticklish sensation, and it has been shown that cancellation of other signals (for example, those that arise from voluntary movement of the eyes) seems to be produced by self-generated “command” signals rather than by external feed-back3,4. Does a similar mechanism exist for the tactile system ? Another question is whether pain is subject to the same type of control; if so, there could be practical clinical applications.