While much of the work in sensory deprivation implies that sufficient sensory input will prevent the occurrence of the disorganizing effects seen, our results suggest that the parameter of meaningfulness of input should be considered. The alerting action of random visual stimulation is not sufficient, under the conditions of our experiment, to prevent the occurrence of mental aberrations. It appears that what the brain needs for normal functioning is not quantity or change in sensation per se, but a continuous meaningful contact with the outside world.Abstract Teaser