Stimulus repetition effects on attention to words and colors.

Mere observation of 30 presentations of a colored form results in slower reaction time responses to the familiarized stimulus than to a comparable novel stimulus. Prior research suggest that this result is due to two subsidiary effects of repetition: alertness decrement and encoding facilitation. Four experiments were conducted to compare the effects of stimulus repetition on colors and words. The two-factor theory of repetition was found to hold for words as well as for colors; for words, in contrast to colors, encoding facilitation was found to be stronger than alertness decrement.