According to Deffenbacher et al. (2004), stress causes the accuracy of both recall and identification to decrease (Sternberg and Sternberg, 2012). Therefore, mental stress caused by sleep deprivation likely influenced the increase in false memory and MCR rate. Another possibility is that sleep deprivation may have reduced participants' ability to engage in elaborate rehearsal or to process items by linking them with prior knowledge (Sternberg and Sternberg, 2012). Sleep deprivation may have prevented the morning coding group from effectively using processing rehearsal. Therefore, within the sleep-deprived morning encoding group less information may have consolidated and a less complete mental representation of events may have formed. When the group was exposed to misinformation in the second phase, memories of the photo sets were recalled into short-term memory. Because the mental representation is more incomplete, photo memory, in this case, is more affected by retroactive interference that occurs when newly learned information inhibits recall of older information (Sternberg and Sternberg, 2012). For the sleep-deprived morning group, misinformation learned during the second phase decreased participants' ability to accurately recall the original information. This theory also explains why sleep