<p>After describing some of the historical influences which led to the world­wide experimental interest in sensory' deprivation and the various techniques that have been devised to achieve sensory restriction, a critical review is presented of the main findings. Because of the voluminous nature of the literature which has developed on this topic since 19 5 1, the emphasis in this article is largely placed upon well-con­trolled laboratory experiments in which human subjects have been exposed to pro­longed periods of isolation and confinement.</p>