Sleep-related false memories production: the influence of impaired sleep quality and of characteristics of the memory task

Previous studies suggested that sleep can influence false memories production. On one hand, some studies found that acute sleep loss can increase false memories production by affecting the efficiency of the memory retrieval process at the subsequent testing time. On the other hand, other researches observed that sleep, compared to a wakefulness period, increases false memories production as a consequence of the memory trace reorganization occurring during the sleep-dependent memory consolidation process. Surprisingly, the relationship between sleep and false memories has been mainly investigated in healthy subjects, neglecting sleep-disordered populations, such as individuals with insomnia. For its peculiarities, the disorder of insomnia might offer an interesting opportunity to study mechanisms underlying false memories production. In particular, focusing on it might allow understanding of whether chronically disturbed sleep influences false memories production by impacting the efficiency of both the memory retrieval and the memory consolidation process occurring during sleep. Therefore, the first main aim of the present PhD project has been to investigate the influence of sleep quality on false memories production, by comparing individuals with insomnia symptoms and good sleepers in different conditions (Study 1, 2, 3). Another issue of the present thesis concerned methodological aspects of the research on sleep and false memories conducted in healthy individuals. Indeed, mixed results emerging from the literature on this topic might be explained in the light of some methodological issues, concerning for example the task selection, the quality of memory encoding, or the individual propensity to produce false memories. Therefore, Study 4 aimed to investigate the effect of sleep on false memories production, respective to wakefulness, taking into account these variables.