The biological benefit of sleep (one of)

‘Sleep appears to be involved in the consolidation of memory. Memories for newly learned material are stronger after eight hours of sleep than after eight hours of wakefulness’ (Smith in Burton, 3rd Ed,  Psychology).

Sleep

'Those who lament that life is too short would be horrified to realise that they will sleep away roughly a third of their time on the Earth, about 25 years. A newborn infant typically sleeps about 70 percent of every 24 hours and typically results in 400-750 hours lost sleep for parents in the first year (The National Sleep Research Project, 2000).
We sleep about one to 1.5 hours less than we did 100 years ago (An Intro to Sleep: What is Sleep, 2007). Anything less than five minutes to fall asleep at night means you are sleep deprived (The National Sleep Research Project, 2000). Ideally, you should take between 10 and 15 minutes to fall asleep.'

Lorelle Burton: Psychology, 3rd Ed, p. 195-196

Subliminal Perception

It is defined as the perception of stimuli below the threshold of consciousness (Burton, Psychology, 3rd Ed, p. 191). Although its effects are not considered large, it has been established to influence thought and emotion. 'Research on subliminal priming clearly demonstrates that presenting people with subliminal stimuli that are positive or negative can influence their emotional reactions and behaviours (Glassman & Andersen, 1997; Weinberger, 2004; in Burton, Psychology, 3rd Ed, p. 191).

Are you letting your children watch any media?
Are you watching any yourself?
Are you ok with being influenced?

Absolute Threshold

According to science, this is the lowest level of stimulus that humans will detect at least 50% of the time. What a wonderful body we live in that we are able to detect such small changes.

• hearing: the ticking of a watch 6 metres away in a quiet place
• smell: one drop of perfume in a large house
• taste: one teaspoon of sugar dissolved in 4 litres of water
• touch: the wing of a fly falling on the cheek from a height of one centimetre
• vision: the flame of a candle 50 kilometres away on a dark, clear night.

(Psychology by Lorelle J Burton, p 209, 5th Ed)