Dreaming is one of the most intriguing aspects of sleep. Most vivid dreams occur during rapid eye movement sleep, a stage characterised by increased brain activity and temporary muscle paralysis.
Although scientists do not fully understand the purpose of dreams, several theories explain how dreaming may support brain function.
Brain activity during dreaming
During REM sleep the brain becomes highly active. Regions associated with emotion, memory and visual processing show particularly high levels of activity.
At the same time the prefrontal cortex, responsible for logical reasoning, becomes less active. This combination may explain why dreams often contain unusual or illogical elements.
Dreaming and memory processing
One theory suggests that dreams help the brain organise memories. During sleep the brain replays experiences from the day, strengthening important connections between neurons.
This process helps integrate new information into long term memory.
Dreams and emotional regulation
Dreaming may also play a role in processing emotional experiences. REM sleep allows the brain to revisit emotional memories while reducing the intensity of stress responses associated with them.
This may help individuals cope with challenging experiences and maintain emotional balance.
Why people forget dreams
Many dreams are forgotten shortly after waking because the brain regions responsible for forming long term memories are less active during REM sleep.
If a person wakes during or immediately after REM sleep, the dream is more likely to be remembered.
References
Stickgold R. Dreaming and Memory Processing
Harvard Medical School Sleep Research
Walker M. Why We Sleep