Placebo sleep affects cognitive functioning.

Objective: The current paper aims to examine the association between self-reported sleep quality and quantity and how these relate to aggression motivation and hostile cognition in a male prisoner sample. The cognitive component of sleep, namely perception, is consequently a variable of particular interest and one neglected by previous research. Methods:Two independent studies are presented. The first comprised 95 adult male prisoners who completed a sleep quality index along with measures of implicit and explicit aggression. The second study extended this to consider aggression motivation and hostile attribution biases using a sample of 141 young male adult prisoners. Results:In study one, sleep quantity and indicators of sleep quality were found not to associate with aggression whereas the perception of poor sleep did; those perceiving poor sleep quality were more likely than those perceiving good sleep to report they had perpetrated aggression in the previous week and to report higher levels of implicit aggression. Study two found that while increased indicators of poor sleep quality were associated with lower prosocial attribution tendencies and higher levels of reactive and proactive aggression, sleep quantity was not associated. The perception of poor quality sleep was important; those perceiving poor sleep were more likely to report higher levels of reactive and proactive aggression than those reporting good sleep. Conclusions:Collectively the studies highlight the importance of accounting for the perception of sleep quality as an important cognitive component in understanding the association between sleep and aggression.Keywords: sleep; aggression motivation; implicit aggression; prisoners SLEEP AND AGGRESSION AMONG PRISONERS 3 Sleep and its association with aggression among prisoners: Quantity or quality?Sleep quality and quantity can impact on cognition, emotion (e.g. Pilcher, Ginter & Sadowsky, 1997;Hyyppa, Kronholm & Mattlar, 1991;Koffel & Watson, 2009) and psychosocial functioning, including relationships (Tavernier & Willoughby, 2014). Poor sleep is known to adversely affect health related quality of life, a concept capturing physical, emotional, mental, social and behavioural components of well-being (Roeser, Eichholz, Schwerdtle, Schlarb & Kübler, 2012a). In non-clinical populations good sleep quantity and quality is correlated with improved health (e.g. Bellec, 1973;Hyyppa et al, 1991). Good sleep quality has, however, been found to relate better to measures of health and well being than sleep quantity, including both depression and anger (Pilcher et al, 1997). In addition, sleep difficulties, including insomnia, poor sleep quality, hypersomnia, fatigue and sleepiness have all been related to symptoms of anxiety and depression; hypersomnia, fatigue and sleepiness related to depression and anxiety more strongly than the other elements and in particular to depression. This was expected since depression can be characterised by such symptoms (e.g. Koffel & Watson 2009). Indeed, the associati...

Objectives-To examine the contribution of sleep disturbance to cognitive performance following blast exposure.Design-Correlational research evaluating self-reported sleep disturbance as a mediator of the association between the primary blast-related comorbidities of mild traumatic brain injury (mTBI) and posttraumatic stress disorder and cognitive outcome. Participants-One hundred sixty Operation Enduring Freedom/Operation Iraqi FreedomVeterans with a history of blast exposure assigned to 1 of 3 groups (no TBI, mTBI without loss of consciousness, and mTBI with loss of consciousness). Main Outcome Measures-Neuropsychological measures and self-report of sleep disturbance.Results-Increased posttraumatic stress disorder symptomatology was associated with worse performance in multiple cognitive domains. This association was mediated in part by self-reported sleep disturbance. Traumatic brain injury with loss of consciousness was associated with lower manual dexterity, but this association was not mediated by sleep disturbance.Conclusions-Our results highlight the importance of sleep disturbance as a factor contributing to cognitive outcome in individuals with posttraumatic stress disorder symptoms. They point to the importance of considering sleep problems in the diagnosis and treatment of cognitive deficits in veterans with blast exposure. U.S. Department of Veterans AffairsPublic Access Author manuscript 20,21 In light of these findings, the presence and impact of sleep abnormalities in individuals with blast injury deserves further attention.Sleep disruption affects a range of health outcomes, including neurocognitive functioning. [22][23][24][25] Individuals with sleep disorders demonstrate deficits on neuropsychological tasks measuring information processing speed, attention, episodic memory, and working memory. 23,26,27 Evidence suggests that sleep problems contribute to the cognitive difficulties observed in both TBI [28][29][30]32 Moreover, improvement in sleep can lead to improvement in cognition in both disorders. 33,34 The above findings motivate the examination of the contribution of sleep disturbances to the cognitive difficulties experienced by OEF/OIF veterans exposed to blast. Previous studies examining associations of chronic mTBI and PTSD with neuropsychological outcomes have highlighted PTSD symptoms as a primary contributor to cognitive impairment. [35][36][37][38] Although there is some evidence that sleep duration may moderate the association between PTSD and cognitive function, 32 no study has directly assessed the overlap among PTSD, sleep disturbance, and cognitive outcomes, while taking into account mTBI-comorbidity. Here, we evaluate whether self-reported sleep disturbance mediates the relationship between PTSD and cognitive outcomes. Such a finding not only would help elucidate the nature of PTSD-associated cognitive difficulties but also would have important implications for treatment. METHODS ParticipantsThe sample consisted of 160 OEF/OIF veterans who reported being within 100...

Built environments with objects that are labeled "environmentally friendly" appear to change people's behavior. For example, one study has shown that labeling a desktop lamp "environmentally friendly" can enhance color discrimination, in comparison with when the lamp is labeled "conventional," even though there is no physical difference between the two lamps. This article explored the generalizability and replicability of this label effect by asking participants to conduct a proofreading task on a desk lit up by a desktop lamp that was either labeled "environmentally friendly" or "conventional"; in reality, the two lamps were identical. Participants high in environmental concern performed better when the lamp was labeled "environmentally friendly." Moreover, the light from the lamp labeled "environmentally friendly" was rated as more comfortable. Taken together, the results seem to suggest that people's beliefs about the source (an environmentally friendly or a conventional lamp) from which the light originates change both rating of comfort and performance. Theoretical explanations and applied implications of these effects are discussed.