NaimExplain

 When do the adolescent sleep patterns tend to shift back? They shift back to an adult pattern around 19.5 years old for females and 21 years for males. Most adults need about 8 hours per night.

Explain adolescent sleep/wake cycles. People tend to become night owls during their teenage years, with their sleep/wake pattern shifting towards the evening (phase delay). Teens need slightly more sleep (9-10 hrs) to function at their best. This suggests that the shift in sleep patterns is biological and normal.

 How is stage 3 and 4 Sleep deprivation linked with growth? Brain is less active and body's metabolism is lower during NREM. This could provide an opportunity for brain cells to be repaired and its waste products to be replaced. Growth hormone is also released. It has been suggested that both REM and NREM are involved in growth and restoration.

 How is REM linked with less protein synthesis in the brain? Studies have shown a greater rate of protein synthesis during REM compared to NREM. These proteins promote the growth of the nervous system (incl brain) and may replenish the brain. Newborns spend about 50% of the sleep in REM, a time when the brain rapidly grows. This decreases to about 20% in adulthood and reflects a decrease in the rate of development. Cause of increase in protein synthesis is unclear, some say the increased blood flow to the brain during REM should actually prevent it.

 How is REM linked with mood disturbances? REM sleep interrupts the release of some neurotransmitters (eg norepinephrine) and this might allow the brain receptors to recover and become more sensitive to their release (more likely to react) after a break. Such neurotransmitters are likely to affect mood and learning. Being deprived may lead to mood disturbances such as grumpiness, irritability and sadness.

How is REM sleep linked with memory and learning problems? Many psychologists believe that the high level of brain activity during REM sleep helps out memories by allowing newly learnt information to be consolidated (transferred) into long term memory. This leads to the idea that not getting enough REM sleep will cause memory problems. It has been proven there is no link (idea is controversial).

It has been suggested that REM and NREM are critical for? REM sleep is more critical for psychological well-being.  NREM is more critical for physiological well-being.  Other psychologists argue against this idea.

 Why are we more susceptible to colds in the lead-up to exams? Lack of sleep increases the levels of cortisol, a stress-related hormone that interferes with immune functioning. After several days of partial sleep deprivation there will be an effect on immunity.

There is increasing evidence that chronic sleep deprivation is linked to serious conditions including Depression Hypertension Heart disease Diabetes Heartburn Obesity Some cancers Anxiety disorders Sleep disorders (insomnia) Accelerated ageing process

 Physiological effects of partial sleep deprivation Slower physical reflexes Hand tremors Droopy eyelids Difficulty in focusing eyes Heightened sensitivity to pain Headaches Lower energy levels

Psychological effects of partial sleep deprivation: Cognitive difficulties: Trouble with attention, concentration, info processing, thinking and reasoning, poor decision making, memory, creativity, perceptual distortions  Affective disturbances: Mood affected, fav activities seem boring, no motivation, fatigue  Behavioral difficulties: Slow performance, clumsiness, risk-taking behaviour, problems with automatic processes

 How dangerous is sleep deprivation while driving? Adelaide researchers found that a driver who has been awake for 17 hours has the same risk of having a car accident as someone with a blood alcohol concentration (BAC) of 0.05 and is twice as likely to have a car accident as a driver with a BAC of 0.00. 24 hours without sleep is equivalent to a BAC of 0.1, making it 7 times more likely for a crash to occur.

 What is partial sleep deprivation? Having some sleep in a 24 hour period but not getting enough to meet your needs.

 Explain how genetics affects the number of hours of sleep needed. Surveys of twins in Aus and Finland found that identical twins tend to have similar sleep patterns than fraternal. Some studies suggest that females tend to need more sleep than males and therefore are more likely to be sleep deprived.

 Explain how lifestyle affects the number of hours of sleep needed. For instance, working day or night shifts, sleeping in quiet or noisy places, leading an active versus inactive lifestyle, and having a stressful versus lowkey way of life all influence our individual need for sleep. We tend to sleep slightly longer in winter than summer, and some culture enjoy an early afternoon nap (siesta). Some get up early everyday, others sleep in on weekends. People tend to alter their sleep routines as responsibilities, relationships and stressors change with age.

Explain how age affects the number of hours of sleep needed. As a guide, most teenagers need 9-10 hours per night. A young child needs more and an adult les to perform at their best.

 How much sleep does each person need? There are no hard and fast rules about the exact amount of sleep we need. Sleep needs vary between individuals and depend on a number of factors such as age, lifestyle and genetics.