Speed and accuracy in the choice reaction time of mildly retarded adults.

Reaction times (RTs) to inside stimuli in an 8-choice task decreased for some retarded subjects when the response ensemble was concealed. Corresponding increases in errors suggested that these subjects made separate visual checks of the response keys in order to respond accurately. Other retarded subjects maintained accurate performance by taking longer to respond. An examination of error data from a number of RT experiments indicated that retarded subjects made more errors than did nonretarded subjects when stimuli and responses were less descriminable. A comparison of RTs for correct and incorrect responses reflected intermittent rather than general tendencies to sacrifice accuracy for speed, a result consistent with the possibility of occasional attentional lapses.