Abstract
This study showed no trends between reaction time and interstimulus intervals and reaction time and time blocks under knowledge of results or no knowledge of results. An ABC × S variance design of reaction time scores showed only knowledge of results by Ss was statistically reliable. The source of this variance was attributed to sex differences. Results showed that under knowledge of results fast mean reaction time (males) was associated with high skin conductance. For females slow mean reaction time was associated with low conductance. Under the no knowledge of results condition, females showed slower mean reaction time than males. Their conductance scores showed significantly greater variability without knowledge of results than under the knowledge condition. Males under no knowledge show mean conductance scores as high as those under knowledge of results. However, their mean reaction time scores under the no knowledge condition was significantly lower than under knowledge of results. It was concluded that males, contrasted with females, respond differentially to knowledge and no knowledge of results in simple reaction time studies. As males show high conductance and females high variability in conductance under no knowledge of results, an inhibition-reinforcement theory for vigilance tasks appears inadequate.