Jess memorize a list of words. One week later, he is asked to write as many of the words as he can recall, but he remembers only a few of the words. Then Jess is asked to fill in the missing letters of word fragments. Some of the words on this task are from the list he had been asked to memorize a week ago, and some are not. Jess fills in the blanks of the words he had seen a week ago faster and more accurately, compared to words that had not been on the list. This study demonstrates the effect of ____.