An investigation of factors that interact with the effect of sleep on false memory in the DRM paradigm
Saudi Digital Library
It is well established that sleep plays an important role in memory consolidation. However, there is a substantial body of evidence which suggests that sleep has the capacity to distort memory and facilitate the creation of false memories. Previous studies examining the effect of sleep on false memory within the Deese-Roediger-McDermott paradigm have reported mixed results, whereby sleep has been found to increase, decrease, and have no effect on false memory. Previous research has suggested multiple factors that could affect false memory formation within DRM. Therefore, this thesis reports on a series of experiments designed to study some of these factors to examine whether they influence the size of sleep effects on the formation of false memories within the DRM paradigm, namely emotionality of the lists, backward associative strength (BAS), list length and inter-item connectivity. This is in order to address inconsistencies in previous research and to increase our understanding of the factors which influence sleep-dependent consolidation of false memories within the DRM paradigm. Additionally, this thesis further differentiates between early and late sleepers to examine which sleep stage is involved in false memory consolidation. It also compares the total sleep time (TST) scored derived from actigraphy watches and sleep diaries to identify the congruence level between the two methods over five consecutive days. The results of the experiments reveal that sleep increases the level of false memory within the DRM paradigm when inter-item connectivity, BAS and list length are manipulated. However, this effect was not observed when emotional lists were used. The results also indicate that there is no significant effect of sleep stages on the formation of false memory. Furthermore, the results from a comparison of the TST measures from the actigraphy watch and sleep diaries suggest that differentiation between the two methods varies on a day-to-day basis. Experiments reported in this thesis are the first which have sought to investigate how sleep interacts with other factors to create false memory within the DRM paradigm. Specifically, the first two experiments experiment are the first that explored the effect of sleep and three types of emotional DRM lists. The third and fourth experiments are the first that investigated how sleep interact with BAS, inter-item connectivity and list length to effect false memory. The fifth experiment is the first that explored the connection between early and late sleep periods and an increase or decrease in false memory. This thesis offers novel findings and adds significantly to the existing literature on sleep and false memory.