Normal sleep is characterized as having four (4) different stages plus an additional type of sleep called REM or rapid eye movement sleep. The four stages are generally characterized by having different types of electrical activity as measured by an electroencephalogram (EEG). Stages 1 and 2 have more rapid electrical activity, yet still slower than that seen during waking. Slow wave sleep (SWS) is most characteristic of stages 3 and 4 which are the stages of deep sleep. REM sleep, however, is characterized by having more rapid brain waves somewhat similar to those seen while one is awake. Dreaming occurs during REM, so it is interesting that the brain wave pattern during REM looks somewhat like that during wakefulness.
Many college students may think that moderate drinking has no negative effects on learning and health. As little as one drink, however, can impair a person’s ability to get a good night’s sleep, which can lead to more significant problems.
Most people find that a drink or two before bed helps them fall asleep faster. This may be true. However, as alcohol is metabolized during the night, sleep becomes progressively lighter and more disturbed. The extent to which cognitive and physical performance is impaired by sleep deprivation is directly related to the degree to which a person is intoxicated at the time he or she falls asleep. Generally, the more an individual is intoxicated, the more sleep is disrupted. What kind of changes in sleep can be expected?
- Total sleep time increases during the first half of the night; it decreases, however, during the second half of the night
- Wakefulness after sleep onset decreases during the first half of the night; it increases, however, during the second half of the night
- Rapid Eye Movement (REM) decreases during the first half of the night; REM rebound occurs in later portions of the night (possible side-effect = nightmares), following alcohol metabolism. Greater levels of intoxication may fully suppress REM sleep and prevent rebound until the following night, because of the set metabolism rate of alcohol (approximately one drink per hour).
- Delta sleep decreases
Disturbances of sleep lead to fatigue and sleepiness during the day. The more one drinks, the faster the person will fall asleep, but the likelihood of sleep disturbances increases. Alcohol consumed up to 6 hours before bedtime can affect sleep patterns, increasing the longevity of disturbances alcohol causes in the body’s sleep cycles.
The average adult sleeps for 8 hrs a night, though different people may need more or less sleep. People who do not get enough sleep are more susceptible to:
- depression disorders
- learning impairment
- poor concentration
- coordination/performance impairment
- decreased cognitive abilities
- memory deficits
- impaired social and occupational function
- medical conditions such as heart disease
Lack of sleep and alcohol consumption are common occurrences in a college student’s life. Many college students are significantly sleep-deprived. The adverse effects of alcohol on sleep magnify this effect. Both of these practices can have negative effects on cognitive abilities, especially when paired together.
From a psychological perspective, it is not uncommon to experience feeling unrested and unrefreshed, groggy and fatigued, and more irritable than usual. Cognitive dampening is also quite common; this is typically experienced as not feeling as “sharp” or “quick” as one usually does. Finally, mental stamina (e.g., the ability to sustain focus and concentration for periods of time) is diminished as well.
Physiologically, sleep deprivation results in the suppression of normal levels of prolactin, cortisol, and growth hormone. Oxygen consumption also decreases at maximum workload; in other words, physical endurance performance may be substantially impaired as a result of temporary impairment to the aerobic pathways.
Information obtained from: ©Academic Skills Center, Dartmouth College 2001 BASICS – A Harm Reduction Approach