Sleep is a process that helps the brain rest and carries out active life processes. While sleeping, a person can dream, which helps process the information received during the day. Dreams themselves are necessary for the ordering of thoughts and reboot the brain, especially the nerve centers responsible for transforming signals from the external environment: hearing, sight, and smell. It means that while dreaming, a person can feel smells, hear sounds, or observe quite clear and connected pictures. Dreams teach to cope with stress and dangerous situations: for example, the “hit or run” mechanism works best in sleep. Dreams are essential for the cycle of life and death because they reflect psychological states and often physiological ones.
The Functional Role of Dreams on a Neural Basis
A dream is a periodic physiological state, a sequence of images that a person can remember. The experience of dreams has been studied in various perspectives in science through the reconstruction of the mental processing of sleep (Mariani et al.). It has several phases, and while attention was first paid to the Rapid Eye Movement (REM) phase, scientists are now interested in the dreaming experience (DE) phase. DE is now thought to play an essential role in emotional coding and regulation, although the neural basis of the REM-DE relationship is discussed as much. The paper by Mariani et al. is a significant review of the available data, which has been analyzed in more than 1,000 scientific articles. This work provides important insights into the neural basis of dreams and emotion processing.
The neural basis of dreams is probably composed of specific cortical systems. One system functions as a regulator of sleep and wakefulness and conditions the temporal-parietal-occipital junction. The other system includes the prefrontal cortex and white matter, which regulate the cessation or loss of sleep. It means that people sleep and dream because there is a marked activation of motor and premotor areas during REM (Mariani et al.). It is thought that the muscle activity observed during the rapid phase accounts for the neural connection to DE. In addition, hyperactive areas (e.g., prefrontal cortex and precuneus) are responsible for the lack of time perception and understanding during DE. These data suggest that people dream because there is an alternating muscular activity of different brain areas, leading to specific images. It is worth noting that this also accounts for the influence of healthy sleep on the construction of emotional response: during DE, emotional experiences are processed, and at the onset of the waking phase, the nerve centers are again ready for new environmental signals.
Physiology and Psychology of Dreams
The physiological basis of sleep was mentioned earlier: fast phases alternate with slow. Due to many switches, it is not always possible to recall all dreams–a phenomenon called dream amnesia. Mutz and Javardi’s work draws attention to each phase and forms an understanding of conscious dreaming and its terminological foundations. This research helps understand the psychological mechanisms of dream realization based on their physiological mode of occurrence and manifestation. Thus, REM sleep is characterized by an increased heart rate, respiratory activity, and muscular atony. In addition, REM sleep is similar to wakefulness because of the high-frequency and low-amplitude electroencephalogram (EEG) curve (Mutz and Javardi). The forebrain is responsible for the rapid sleep phase and dream formation, although evidence suggests that its disturbances result in a lack of dreaming and retention of the dream phase. The reverse is true for brainstem lesions: no fast sleep phase occurs, but people can report images upon awakening.
Slow sleep is of greater interest to the scientific community because less time was initially devoted to it. Physiologically, slow dreaming is divided into stages N1, N2, and N3, which differ in the number of possible dream images. During N1, all dream reports are thought to be largely echoes of the fast phase; during N2, virtually no dreams are recorded; during N3, DE is due to slow EEG waves (Mutz and Javardi). These data indicate that the occurrence of dreams is influenced by temporal factors and by images experienced before the rapid phase of sleep. In terms of psychological experiences, dreaming arises because of the thought-like thinking characteristic of the N1 and N2 stages, which is due to low-frequency electrical signal transmission.
Emotional Processing in Dreams
Dreams and dreaming are closely related to the processing of experienced emotional responses. The scientific world adheres to the dreaming continuity hypothesis, which states that dreams are a natural continuation of the sleeper’s thoughts and experiences. The emotional tone of dreams, in this case, depends on the emotional experience of the person and the degree of influence of external factors on it. Scarpelli et al.’s study focuses on the impact of the external environment on the formation of dreams and the identification of affecters that are more tied to the stages of the referential process. The paper is based on the emotional trauma received during the COVID-19 pandemic, making it relevant and valuable for understanding the influence of society on the themes and images of dreams.
The referential process consists of arousal, symbolization, and reorganization, which vary according to socio-demographic indicators. Scarpelli et al.’s research conducted a study that found that dream narratives reflect the emotional and cognitive processing of the experience of isolation. It was done using linguistic tools that assessed how people self-interpreted dreams. It was determined that people rarely communicate arousal phase dreams because the sensory experiences of dreams are not recorded upon awakening (Scarpelli et al.). That said, the quality of emotion processing refers to how people can convey dreams linearly. These results indicate that people dream due to external factors related to isolation and social interaction; in the limitation of communication, dreams are no longer conscious.
Outcomes and Discussion
Sleep is a complex issue to which different functional parts of the body are relevant. Scarpelli et al. and Mariani et al.’s papers focused specifically on the emotional load, which is nullified during sleep. The psychological effect of dreams is necessary for people more than their physiological component because the redistribution of mental resources is necessary for life activity. Dreams are a reflection of unconscious processes that are not controlled during sleep. Although people report quite emotional images and nightmares during sleep, this does not mean that people are in control of what they dream (Mariami et al.). The notion of control in dreams is generally absent, according to the studied literature: the term is not used because it suggests a different meaning to dreams that are not related to psychology. Depending on the psychological component of dreams, it is essential to understand that emotions prevail over other categories of consciousness. The emotional coloring of dreams determines their function and degree of rest.
Lack of control is also justified by exposure to the environment and emotional response; the magnitude and duration of exposure are the main susceptibility criteria. Scarpelli et al.’s paper draws attention to this: the outside world invariably influences the formation of dreams, but they are still not grounded in the person’s desire. In turn, Mariani et al. confirm this by claiming the involvement of higher nervous activity to unload during sleep. However, this condition makes their article similar to the work of Mutz and Javardi, who are interested in the physiological separation of sleep phases. Although all three papers focus on the emotional background and external stress that shape the need for dreams, only Mutz and Javardi relate to sleep and dreaming. The authors believe that nerve impulse transmission is more important than the environmentally induced psychological effect.
Thus, dreams are a vital part of the life process because they play a role in emotional processing. Various studies indicate that changes in the physiological phases of sleep account for the variety of images people register upon awakening. Neuronal connections and muscle activity of different brain regions play a role in regulating dreams. Recent studies indicate that dreams are caused by limiting environmental factors. The results obtained during the analysis of the articles show that dreams reflect the emotional stress received during life activity, the nullification of which occurs at different stages of sleep. Physiological redistribution of accumulated stress is justified by the need for multiple neural responses, in which adequate rest is possible. It causes the transformation of signals received from the external environment: for example, how pandemic conditions formed disturbing dreams in people.
Mariani, Rachele et al. “Dreaming in quarantine: linguistic analysis of referential process of dreams during COVID-19 pandemic lockdown.” Research in psychotherapy (Milano) vol. 24, 2021. doi:10.4081/ripppo.2021.537
Mutz, Julian, and Javadi, Amir-Homayoun. “Exploring the neural correlates of dream phenomenology and altered states of consciousness during sleep.” Neuroscience of Consciousness, vol. 2017, no. 1, 2017. doi:10.1093/nc/nix009
Scarpelli, Serena et al. “The Functional Role of Dream in Emotional Processes.” Frontiers in Psychology, vol. 10:459, 2019. doi: 10.3389/fpsyg.2019.00459.