The existence of the paradoxical sleep phase and its linkages to dreams was discovered in 1950. The dream is the crucial moment of paradoxical sleep. There is no scientific examination to ensure 100% that the subject in a paradoxical sleep period is dreaming. But the empirical experience shows, when you awaken the sleepers during this phase for example, that this is very often the case. Thus, people who are awakened during REM sleep remember their dreams in 85% of cases, compared with 10% to 15% during slow sleep. At a rate of 15 to 20 minutes of paradoxical sleep per cycle and 4 to 5 cycles per night, it is estimated that an individual dreams on average 100 minutes or 1 hour 40 minutes each night. So a 60-year-old spent about 5 years of his life dreaming and, in total, 20 to sleep! Paradoxical sleep is the dream phase.
The cycles of a night’s sleep are not all equal: during the first cycle, the phase of slow and deep sleep is very long, that of paradoxical sleep is at the shortest. Overnight, the slow sleep cycle becomes shorter, while the REM sleep phase lengthens. This explains two phenomena: The duration of dreams lengthens over the night. The first dream lasts about ten minutes, the second about twenty while the following can last half an hour. They are the ones best remembered since they take place at the end of the night.
It is said that the first hours of sleep count double because of the quantity of “restorative” sleep, the one where the body and the brain are at rest, is more important in the early cycles. Thus there are more or less “good dreamers”, without knowing why. Without any particular pathology or medical treatment, everyone dreams. But you do not all have the same ability to dream and remember them.
Thus, women seem to dream more than men and are affected by this sleep behavior disorders. Awakened during a phase of REM sleep, 95% of them remember what they were dreaming, compared with 80% of men only. They are also able to give a more detailed account of the events, which also seem to last longer. Women are also more likely to have nightmares than their male counterparts. Scientists today do not have a scientific explanation for this phenomenon. At the very most, one can draw a parallel with the fact that women are often endowed with a greater “emotional imagination” than men and therefore perhaps more inclined to dream in a rich and detailed way. Nor do we dream the same way at all ages. It is very complicated to determine at what age a child starts to dream and the specialists do not agree with each other.
It seems that in the first months or even the first few years of life, the baby and the child are rather victims of terrors night, a phenomenon that is not akin to the dream that occurs during REM sleep than during sleep paradoxical. The longer you go into the night, the longer the periods of REM sleep, at the expense of the slow sleep phase. Thus, it seems that the capacity to dream rises in power in the first months of life, as does the cognitive capacity of an individual. Conversely, this ability to dream would also diminish with age and seniors would thus make fewer dreams than adults in full bloom of age. Here again, it is impossible to generalize or to have certainties, but two elements support this hypothesis: Seniors often sleep less than younger: REM sleep stretches into late night, at the third and fourth cycles. It is, therefore, likely that the elderly simply have less REM sleep at their disposal to dream; Like other organs, the brain ages and “rusts “with age.
The neuronal plasticity decreases that is to say that the neurons become less adaptable; the connections between them are sometimes less good. That’s why it’s harder to learn new things as you get older than when you’re a high school student. In the same way, this lack of plasticity could play a role in the imagination and the dream.