Why do we dream? The science behind dreams

Dreams have fascinated humanity for centuries. Since ancient times, different cultures have tried to interpret their meanings, considering them divine messages, predictions of the future or manifestations of the subconscious. However, in recent decades, science has made considerable progress in the study of dreams, revealing valuable information about their function and their relationship with the brain. In this article, we will explore why we dream from a neuroscientific and psychological perspective, analyzing the different theories, functions and factors that influence this phenomenon.

1. Sleep and its Stages

Sleep is divided into several phases, each with distinct characteristics and specific functions in rest and brain activity:

• Stage 1 (Light Sleep): This is the transition between wakefulness and sleep. Brain activity is reduced and muscles begin to relax. During this stage, it is common to experience muscle twitching or the sensation of falling.

• Stage 2: Sleep deepens and the brain begins to show patterns characteristic of stable sleep. During this stage, body temperature drops and heart and breathing rates stabilize.

• Phase 3 (Deep or Slow Wave Sleep): This is the most restorative phase, where the body regenerates and certain cognitive processes are consolidated. During this stage, essential functions such as tissue repair, strengthening of the immune system and elimination of brain toxins take place.

• REM (Rapid Eye Movement) phase: This is where most vivid dreams occur. During this phase, brain activity is very similar to that of wakefulness, but the body is temporarily paralyzed to prevent us from acting out our dreams. This phase is also thought to be crucial for emotional memory consolidation and learning.

2. Scientific Theories about Dreams

Scientists have developed several theories to explain why we dream, each based on different findings and interpretations of brain function:

a) Information Processing Theory

According to this theory, dreams help process information and consolidate memory. During the day, the brain receives a large amount of data, and while we sleep, it organizes and stores the relevant information, eliminating the unnecessary. This mechanism is believed to be essential for learning and decision-making in daily life.

b) Freud's Psychoanalytic Theory

Sigmund Freud suggested that dreams were manifestations of repressed desires. According to his theory, dreams contain symbols that represent internal conflicts or unconscious desires. Although this theory has been widely debated, it remains influential in modern psychology and dream analysis in therapy.

c) Threat Simulation Theory

Proposed by neuroscientist Antti Revonsuo, this theory holds that dreams function as simulations that prepare us to face real dangers. For example, dreaming about dangerous situations could help us respond better in similar circumstances in real life, increasing our chances of survival.

d) Activation-Synthesis Hypothesis

This theory, developed by J. Allan Hobson and Robert McCarley, holds that dreams are the result of random brain activity during REM sleep. According to this hypothesis, the brain tries to make sense of these random signals, creating narratives that we experience as dreams. This would explain why some dreams seem chaotic or make no logical sense.

3. Functions of Dreams

Although there is still debate about the exact function of dreams, research suggests that they play several key roles in our mental health and overall well-being:

• Memory consolidation: Dreams can help reinforce memories and improve learning. During REM sleep, the brain reorganizes and strengthens information acquired during the day.

• Emotional regulation: Dreaming may help us process emotional experiences and reduce the impact of stressful events. Some studies suggest that REM sleep facilitates adaptation to traumatic situations.

• Creativity and problem solving: Many innovative ideas have arisen from dreams, such as Watson and Crick's theory of the structure of DNA or Elias Howe's invention of the sewing machine.

• Neurological maintenance: Some researchers believe that dreams help maintain brain health by strengthening neural connections and removing irrelevant information.

4. Lucid Dreams and Their Relationship with Science

Lucid dreaming is when the person is aware that they are dreaming and can even influence the content of the dream. Research suggests that lucid dreaming training may have therapeutic applications, helping people with recurring nightmares, phobias, and even improving cognitive and creative abilities. Techniques such as reality checking and induced awakening have been developed to facilitate the practice of lucid dreaming.

5. Factors that Influence Dreams

Several elements can affect the quality and content of dreams:

• Stress and anxiety: These can trigger vivid dreams or nightmares. Chronic stress can increase the frequency of disturbing dreams.

• Diet and substances: Caffeine, alcohol, and some medications can disrupt REM sleep, reducing your ability to dream or remember dreams.

• Sleep deprivation: Lack of sleep can affect your ability to remember dreams and the quality of your rest. Lack of REM sleep can have negative effects on memory and mood.

• Environmental factors: Temperature, noise and light can influence the intensity and quality of dreams. A suitable sleeping environment improves the quality of rest and, therefore, dreams.

Conclusion

Although there is still no definitive explanation for why we dream, science has made considerable progress in understanding dreams and their importance for the brain. From memory consolidation to emotional regulation, dreams play a crucial role in our lives. As research continues, we are likely to discover even more about this fascinating phenomenon. Better understanding dreams can help us improve sleep quality, optimize mental health, and boost creativity.

Sources and Links

• National Sleep Foundation: www.sleepfoundation.org

• Harvard Medical School - Division of Sleep Medicine: sleep.hms.harvard.edu

• Neuroscience News: www.neurosciencenews.com