Altered states of awareness refer to any state involving loss of conscious control of behaviour such as drug induced states, sleep states and dream states. As a great deal of research has been carried out into all three altered states it is not possible to do justice to all three areas in a time restricted essay therefore it is the latter two altered states of awareness that will be considered in this essay.
Research into sleep (a circadian rhythm) has shown that sleep consists of a number of cycles (ultradian rhythms) during which the sleeper's state awareness is altered many times. As the person moves from a waking state into the hypnogogic state their awareness of the outside world becomes limited and their muscle tone relaxes and their eyes begin to make slow rolling movements. However the sleeper is fairly responsive to external stimuli and if wakened during this stage they often report that they were not asleep at all.
Polysomnography (PSG) is a multi-parametric test u...
English: Stage 2 sleep. Sleep spindles highlighted...
Sleep waves (EEG highlighted above) recorded from ...In the second stage of sleep their awareness of the outside world decreases and the sleeper's waking threshold lowers thus it becomes increasingly harder for external stimuli to waken the sleeper. Nevertheless there is still some responsiveness to specific external stimuli for example their distressed infant or child can readily awaken a parent during this state or if the stimuli is strong such as a very loud bang.
Progression into stage three of the sleep cycle causes the sleeper to become even less aware of external stimuli thus even strong stimuli is unlikely to readily awaken the sleeper. In stage four sees awareness of external stimuli drop even lower and it is now exceedingly difficult to waken the sleeper. However if they are eventually wakened from this altered state of awareness they report feeling very groggy and disorientated. As stage...