Since Helmholtz succeeded in 1850 in measuring the speed of conduction in a frog's motor nerve, a great many investigators have measured a variety of simple and complex reaction times in humans and lower animals (47). A survey of the literature, however, confirms Rosenblith's (36) observation that data on response times for comparable sensory tasks in individuals who have suffered neurological damage are clearly lacking. The present study, therefore, while deviating somewhat from the ordinary reaction time experiment, is an attempt to measure initiatory delay in children with aphasia. Initiatory delay in this study was defined operationally as "the time elapsing from the moment of stimulus presentation to the beginning of a naming response."