Restoration Theory Two Main sub-theories Oswold’s (1980) Restoration Theory: Horne’s (1988) core sleep model: Research into the theories **KEY STUDY** Gulevich, Demend and Johnson (1966) Sleep deprivation study of Randy Gardner. 17- year old school boy attempting to break the record for longest time of wakefulness, staying awake for 264 hours and 12 minutes. Finding that lack of sleep alters vision, coordination, hallucinations, lapses in memory and concentration. After the study Randy slept for just 14 hours and soon returned to his usual 8hour pattern. Concluding that stage 4 and REM sleep are most important and it is possible to have long period of sleep deprivation with suffering long term effects. Further Research into the theories Everson et al (1989) Found that depriving rats of sleep causes increased metabolic rate, loss of weight and death in about 19 days, possibly due to immune system damage, suggesting that sleep is necessary for restoration. The theory that people sleep to rejuvenate and repair This explanation sees sleep as helping to reverse and/or restore biochemical and/or physiological processes that are progressively degraded during the day. High levels of brain activity during sleep indicate brain restoration. Sleeping does not supply any repair functions except for the brain (most process’s occur whilst awake- digestion, removal of waste products). He saw core sleep to be essential for brain restoration, and optional sleep, whose main purpose is energy conservation. The study was poorly controlled with a lack of objective measurements (no EEG readings were taken so micro-sleeps could have occurred.) Natural experiment- high external validity but extraneous variables weren’t controlled therefore lowering the reliability of the study. Participants in sleep studies are aware that they are being studied which might increase their stress levels. Daily routines, like work and leisure time, are suspended, making results difficult to generalise to more realistic situations. Ethical issues with using rats as they died- but using rats good due to fast reproductive cycles Hard to extrapolate as rats have different brain structures to humans Laboratory experiment means low extraneous variables, but low mundane realism Provides evidence for restoration theory. Horne (1988) Performed a meta-analysis of sleep deprivation studies, finding little evidence of reduced physical functioning or stress responses, suggesting that sleep is not primarily for restoration. Cirelli et al (2004) Found that during SWS, genes associated with the protein production regulating synaptic connections are activated, supporting restorations theories. Practical Application Meta-analysis – has an overview of one area, but doesn’t offer any new evidence and is open to personal interpretation Evidence against restoration theory Supports Oswold’s restoration Theory Biological approach- Doesn’t take into account individual and cultural differences To research this, participants would have to be studied using an EEG and therefore true sleep patterns may not be reflected. Endurance based athletes use short sleep sessions after intensive training to promote protein synthesis to repain tissues. Lending support the to the idea of sleep being for restoration.