title: Relief expectation and sleep.
abstract: Originally, a role for sleep in learning and memory has been advocated following the observation of sleep-dependent performance enhancements at simple procedural tasks. With the investigation of a variety of cognitive and behavioral abilities, multiple stages of memory were further suggested to benefit from the off-line reprocessing believed to occur during specific sleep stages. In particular, REM sleep has been implicated in the integration of new information into associative networks as well as in the abstraction and generalization of implicit rules allowing adaptive behaviors. In a recent study, we extended these observations by demonstrating that the mediating effect of expectation on placebo-induced analgesia is strengthened by sleep, and that the individual amount of REM sleep is predictive of the relief expected on the next morning. However, this relation is strongly modulated by the level of concordance between expectations and sensory information available prior to sleep. As placebo responses derive from the learned association between contextual cues and subsequent relief, these results are discussed in relation to the proposed roles of REM sleep in the integrative stages of memory processing. In light of the responsiveness of REM sleep to waking events, its expression is also proposed to reflect the cognitive demand associated with the offline reprocessing of information necessary for the assimilation of new expectations to one's belief system.
authors.affiliation: Department of Physiology, Faculty of Medicine, University de Montréal, Montréal, Canada. daniele.laverdure-dupont@umontreal.ca
authors.forename: Danièle
authors.initials: D
authors.lastname: Laverdure-Dupont
authors.forename: Pierre
authors.initials: P
authors.lastname: Rainville
authors.forename: Jacques
authors.initials: J
authors.lastname: Montplaisir
authors.forename: Gilles
authors.initials: G
authors.lastname: Lavigne
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D003469:Culture; D006801:Humans; D007858:Learning / Q000502:physiology*; D008606:Mental Processes / Q000502:physiology*; D012890:Sleep / Q000502:physiology*