The subject of false memories—memories for events

rating. For example, the participants were told that tree is a very concrete item since one can touch it, whereas justice is very abstract since it is impossible to touch. These participants were givensince it is impossible to touch. These participants were given a scale on the top of a rating sheet that had a range of choices from 1 (very concrete) to 5 (very abstract). Following the list presentation, the participants engaged in a 5-min unrelated filler task. The purpose of this task was to eliminate any rehearsal of list items in addition to any recency effects of memory. Finally, the participants were administered a free-recall test and instructed to write down as many of the list items as they could remember in any order. They were given 5 min for the recall test. Results and Discussion A 2 (level of processing: shallow, deep) 3 2 (item type: list, critical lure) analysis of variance (ANOVA) was conducted on the proportion of items recalled. Table 1 presents the mean proportions of list items and critical lures recalled for both the shallowand deep-processing conditions. Results revealed a main effect of both level of processing [F(1,38) 5 8.81, MSe 5 0.07, p < .05 (an alpha level of .05 was used for all statistical tests unless otherwise noted)] and item type [F(1,38) 5 7.03, MSe 5 0.04]. However, there was no level of processing 3 item type interaction [F(1,38) 5 2.00, MSe 5 0.04]. Followup t tests were conducted to further examine these data. In line with the levels-of-processing theory, the participants in the deep-level-of-processing condition (.29) recalled a significantly greater proportion of list items than did the participants in the shallow-level-of-processing condition (.18) [t(38) 5 22.875]. More importantly, participants in the deep-level-of-processing condition recalled a significantly greater proportion of critical lures than did the participants in the shallow-level-of-processing condition (.47 and .23, respectively) [t(38) 5 22.459]. Hence, the present findings lend support to the idea that a deeper level of processing results in greater activation of list items and their associates rather than an overall improvement in memory performance as predicted by the levels-of-processing approach. A follow-up t test was also conducted to determine whether the participants in the deep-level-of-processing condition demonstrated higher guessing rates than the participants in the shallow-level-of-processing condition using the number of noncritical intrusions recalled. Specifically, a greater number of noncritical intrusions in the deep-level-of-processing condition would indicate that the participants were employing a guessing strategy, the result of which would be greater recall of list items and critical lures as well as the noncritical instrusions. However, results indicated that there was no difference in the number of noncritical intrusions recalled between the deep-level-of-processing condition (3.95) and the shallowlevel-of-processing condition (2.95) [t(38) 5 20.70]. The results of Experiment 1 demonstrated that the deeper level of processing utilized at encoding led to greater activation of the list items and their associates, including the critical lures. This is illustrated by the fact that the levels-of-processing manipulation had a significant effect on the proportion of list items recalled as well as critical lures. Hence, a deeper level of processing led to more accurate memory for list items but, as activationbased theories would predict, a greater number of memory illusions.