DREAMS’ NEUROPHYSIOLOGY: INTEGRATION OF NEUROSCIENCE CONCEPTS AND PSYCHOANALYSIS

Objectives: Evaluate the available informations about dreams, analyzing hypotheses of the neuroscience and psychoanalysis. It is proposed to show discoveries of the dreams’ neurobiology as well as how psychology can explain this phenomenon, in order to observe an integration between these perspectives. Methods: For this literature review studies were selected (databases - MEDLINE, PUBMED, SCIENCE DIRECT, SciELO and LILACS -, websites and Scientific Journals) on neuroscience and psychoanalysis with approaches of neurobiological processes and dreams meanings. Main Findings: On the selected studies about this theme, were described the dreams neurobiology besides hypotheses about the origins and functions about them. Psychoanalytic theories are referred for demonstrate the dreams influence under the emotions and vice versa. Research Implications: There is a connection between studies about dreams from neuroscience and psychoanalysis, which is propelling new researches. Psychotherapy shows empirical results about dreams, which have inspired and guided neuroscientific investigations. There are studies that discuss the relationship between studies about dreams in neuroscience and psychoanalysis, and those are essential to obtain a better understanding of the complexity that surrounds the meaning of dreams at psychosocial and neurophysiological fields. Within this proposal, the present paper expands the understanding of the interrelationships and integration of concepts between neuroscience and psychoanalysis repertory about the dreams. Originality/value: The paper contributes with the literature of the specific area in the area, due the perspective on psychoanalytic theories of neurobiological functions, and the importance of interconnecting the concepts involved in understanding the phenomenology of dreams.


INTRODUCTION
Dreaming can be defined as an altered mental state of consciousness that occurs during the sleep. Dreams usually involve fictional events that are organized at a similar manners with the aim of form a story, characterized by a series of sensory, perceptive and emotional experiences which were internally generated (Mutz and Javadi, 2017).
Even today the act of dreaming is not understood completely. Although the neuroscientific approach to dreams emerged in the final decade of 1950s, the neurophysiological correlation of dreams are still unclear and many questions remain unsolved (Ruby, 2011). In 1900, Freud already assumed teleologically that the purpose of dreaming was the discharge of accumulated psychophysiological 'energy' and, consequently, the return to an earlier state of quiescence (Caviglia, 2021). The findings of 1950s neurophysiological research supported the idea that the primary aim of the dream is "informative" (rather than energetic). Dreaming allows the individual to classify, process and keep in memory the accumulated stimuli and information to promote a better adaptation to reality (Caviglia, 2021).
Despite scientific discoveries, the popular belief about dreams make reference to "hidden truths", with capacity of transmitting important messages about the world and also the one who dream it, reflecting the interests and personality of individuals, as well as their ___________________________________________________________________________ Rev. Gest. Soc. Ambient. | Miami | v.17.n.2 | p.1-19 | e03416 | 2023.
3 respectives possible anxious experiences, the mood and concerns about what they experienced awake (Scott and Ribeiro, 2010).
Dreams show that our brain, disconnected from the external environment, can create for itself an entire world of conscious experiences (Nir and Tononi, 2010). Researches suggests that the dream is the function of the brain and mind that works at a different manner, but not inferior compared with awakened consciousness (Bulkeley, 2017).
Over the past decades, several biological and psychological theories about the purpose of the dream have been showed (Mutz and Javadi, 2017). Three specifically kinds of researches are especially promising: neuroscientific studies of activities during sleep; systematic analyzes of dream in several populations; and psychotherapeutic studies with explorations of the multiple dimensions of personal and collective meanings add with dreams experiences interpreted by each individual (Bulkeley, 2017).
The study of the dreams is challenge, since the consciousness during dreaming is not possible to be done by direct observation (Nir and Tononi, 2010). Due to the random nature and personal relevance of dreams contents, it is not yet possible to construct a common theory justifying the possible function of Dreams, on a universally way (Krishnan, 2021). With the advance in science and technology, there is hope to understand the signs and the basics mechanism of sleep and dreams (Krishnan, 2021). Since that dreaming is a physiological need, it is fundamental to evaluate the sleep as a predictor of health (Matricciani et al, 2019).
The first scientific approach to dreams was initiated by Sigmund Freud in the early 20th century, corroborating the ancestral notion that the dream phenomenon reflects 'hidden truths'. However, this can be observed in relation of the person who possesses the dream, and not to external, magical or sacred sources. For psychoanalysis, dreams contain hidden desires and emoticons which can be interpreted, providing tools to get the individual's unconscious (Scott and Ribeiro, 2010). Psychoanalysis also provides hypotheses used for to treat some psychological concerns that have received minimal attention in the neuroscience. The recent development of neuropsychoanalysis brings new hopes about the interaction between science and analytical approach, cause consider that the psychoanalytic perspective in cognitive neuroscience can provides new directions and clues to researching add a extensive comprehension of the dream (Ruby, 2011).
In order to provide an overview of the neurobiological genesis and function of dreams and sleep, this literature review was conducted to promote one analysis of dreams processes from a neuroscience and psychoanalysis perspective, in focus on their correlations and mechanisms of multisensory integration, showing an integration of these perspectives and possible implications.

METHODOLOGY
The literature review about the proposed theme was made by searching on MEDLINE, PUBMED, SCIENCE DIRECT, SciELO and LILACS databases, using as keywords: sleep, review, neuroscience, neurophysiology, psychoanalysis; and as key words: sleep, revision, neuroscience, neurophysiology, psychoanalysis.
The studies with better descriptions about the theme were chosen, including reviewing papers, without a specific year of publishing and in Portuguese, English or Spanish languages. No specific periods of publication or restriction were established regarding the design of the study, and original articles were selected in Portuguese, English and Spanish.

Sleep neurophysiology
Sleep is defined as a behavior characterized by: decreases motor activity and interaction with the external environment, one specific posture (e.g. lying down, closed eyes), and easy reversibility (Jiang, 2019). The architectural organization of sleep refers to the coordination of independent neurophysiological systems in 3 distinct functional states: non rapid eye movement (NREM), rapid eye movement (REM), and wakefulness. Each state is distinctly associated with a pattern of brain electrical activity (Jiang, 2019).

Sleep Cycles
Sleep can be divided in two phases: non-rapid eye movement (NREM) and rapid eye movement (REM). The sleep cycle includes three NREM stages, followed by the REM stage. Each cycle lasts about 1-1.5 h and there are many rounds of these sleep cycles (approximately 5-6 cycles), making 7-8 h as the ideal sleep duration (Krishnan, 2021).
The NREM phase has three stages: stage 1 (N1), stage 2 (N2), and stage 3 (N3) depending on the rhythm of the brainly synapses, evaluated in electrical waves. NREM stage 1 or N1 is the initiation stage where a person start the sleep phenomenon, lasting about 1-7 min, with alpha rhythms of at 8-13 cycles per second, and at this stage someone can be easily awakened (Krishnan, 2021). Stage 2 (N2) lasts approximately 10-25 minutes in the initial sleep cycle, but can consume 50% of the total sleep cycle at the end of the night. Stage 2 is a much deeper sleep state than stage 1, but individuals can be awakened with strong stimulation (Krishnan, 2021). The NREM stage 3 (N3) lasts about 20-40 min, characterized by high-voltage EEG and slow-wave frequency. This is the 'deep sleep' stage and dreams are experienced at this stage as well, but it is distinct in comparison to REM dreams. Upon waking up at this stage, people can barely remember or remember any experience they have had due to the impairment in the interaction capacity of the surrounding cortical neurons (Krishnan, 2021).
Sleep patterns change with age during the first ages of life. The characteristics of sleepwake states during initial development originate from activity-rest cycles in the fetus and in the first months after born (Jiang, 2019). Sleep states are categorized as active sleep, quiet sleep, and indeterminate sleep in very young infants. In the second half of the first age, quiet sleep gradually passes into NREM sleep. Meanwhile, active sleep characterized by frequent, grim muscle spasms transforms into REM sleep. After 6 months of age, NREM and REM sleep patterns progressively resemble those observed in adults (Bathory et al, 2017).
The level and nature of conscious experience can change dramatically in sleep. During slow-wave sleep in the early evening, consciousness can almost disappear despite persistent neural activity in the thalamic-cortical system. Subjects awakened from other phases of sleep, especially but not exclusively during REM sleep, report "typical" dreams, in which sensory hallucinations is made by a narrative structure. The dreamer is highly conscious (with vivid experiences), is disconnected from the environment (is sleeping), but somehow his brain is creating a story, filling it with actors and scenarios, and generating hallucinatory images (Nir and Tononi, 2010).
It was later showed that the dream also occurs during the NREM phase. Interestingly, there is a difference in the nature of dreams between the two phases, ranging from normal dreams to less complex in the NREM phase to lucid type in the REM stage (Krishnan, 2021).

Ontogeny, Neurobiological Functions and Theories about the Origin of Dreams
The evolutionary success of the human species has largely depended on differentiated cognitive abilities, and these abilities depend on a brain-mind system that operates 24 hours a day, waking up or sleeping (Bulkeley, 2017).
The main components of the emerging psychological architecture of humans (psychological functions and processes, including sensation, perception, memory and executive functions, etc.) have been shown to be characterized by a specific pattern of development. The development perspective implies considering the dream as a mental activity inherently linked to neural maturation, possibly reflecting changing neural and cognitive processes (Sandor et al., 2014).
The evolutionary and biological functions of the dream are still unclear (Stickgold and Zadra, 2021). Dreaming can play an important role in reactivating and consolidating new and individually relevant experiences that occurred during wakefulness hours and can also constitute a biological defense mechanism, which evolved as an ability to repeatedly simulate threatening situations (Mutz and Javadi, 2017). Sleep and appetite have a circadian tendency with a diurnal rhythm, influencing the maintenance of body mass. There is a reciprocal interaction between sleep and obesity: poor sleep, whether in quantity or time, is associated with difficulty controlling appetite, resulting in obesity (Lee and Choo, 2022).
Early childhood life is a critical period in which the normative transition of sleep-wake patterns occurs, characterized by consolidation of night sleep and interruption of day sleep (Jiang, 2019). Sleep plays a critical role in mental health and psychosocial adjustment throughout life. Sleep in children and adolescents plays an important role in cognitive, emotional and physical development (Lee and Choo, 2022), being essential for children's health and well-being (Jianag, 2019). The quality, time and variability of sleep in children can influence cognitive, psychosocial and cardiometabolic health in children, being of particular interest, as many behaviors and lifestyle conditions in childhood follow until adulthood (Matricciani et al, 2019).
There are correlations between the maturation of human sleep and the ontogeny of the dream. REM sleep may appear at a very young age, since the neurons responsible for lateral eye movements present myelin at an early stage of fetal development (Sandór et al, 2014). Later, the newborn spends 50% of its sleep time in REM sleep which is proven to be closely connected with the intensive neural development of this age (Grigg-Damberger et al, 2016). This fact led some scientists to conclude that the dream also occurs at this young age and that it plays an equally important role in development (Sandór et al, 2014).
The REM sleep of infants, however, differs from that of adults in both electroencephalography (EEG) and behavioral characteristics, so its presence alone does not prove the existence of the dream. According to some authors, REM sleep elements gradually merge over the course of pre-and postnatal development to form the most solid and distinct features of adult REM sleep. This could serve as a basis for the idea that dreaming involves a similar development, implying the gradual increase in the cohesion of these components (Sandór et al, 2014). The increased time spent sleeping in infants and early childhood is believed to reflect the crucial role sleep plays in promoting optimal brain development, cognition, and behavior. The temporal course of REM development (and decline) in humans corresponds to critical periods of brain maturation (Grigg-Damberger et al, 2016).
It is a hypothesis that the dream reflects the processing of memory in the sleeping brain. During sleep, the activity of memory networks is evident in the content of subjective experience, as recent waking experiences are often unequivocally represented in the content of night dreams (Wamsley and Stickgold, 2019). At present, it is suggested that the REM phase of sleep plays a complex role in health and, more specifically, in regulating mood and emotion.
Short-term interruptions of REM sleep can increase irritability, anxiety and aggressiveness (Naiman, 2017).
There is still no general methodological pattern in the study of dreams and in the determination of their content and of their psychophysiological correlates. The content of dreams is not predictable, and most modern researches abut the dreams attempts to relate neuronal activity rather than the content of dreams, i.e. the focus is on the properties of all dreams rather than investigating the neural correlations of one dream (Nir and Tononi, 2010). Most studies use either experimental manipulation of dream content or correlational projects are conducted (Stickgold and Zadra, 2021). It is often hard to determine in what sleep time the dream occurred, making it difficult to do some correlation (Stickgold and Zadra, 2021). Still, it is difficult to manipulate the content of dreams experimentally, either by stimullation before or during the sleep (Nir and Tononi, 2010).

Neurobiological Theories on the Origin of Dreams
Sleep is one of the primary brain activities during early development and plays an important role in cognitive health and psychosocial development during all embryo and born life (Jiang, 2019). It is possible that dreaming can serve as a function, and a modification of that function, or a new function, at another time in the individual's existence process. For example, its can conceive an experience or psychological function onto a more basic biological function with ontogenetic development as the personality develops and has more experiential 'rolling stock' to deal with, such as the increasing psychological complexity of dreams observed that accompanies the growth of a child (Staunton, 2001).
Some studies have shown the involvement of prefrontal and parietal regions of the brain in lucid dreams (Baird, Mota-Rolim, and Dresler, 2019). Frequent lucid dreaming is linked to increased functional connectivity between left anterior prefrontal cortex and bilateral middle temporal gyrus, right inferior frontal gyrus, and bilateral angular gyrus (Baird et al, 2018).
One of the main neurobiological functions of dreams concerns the role of sleep in the consolidation of memories and the involvement of the hippocampus in the acquisition of memories. As main findings that corroborate this fact, suggesting that sleep facilitates the processing of new information, one can cite the negative effect of sleep deprivation on learning, the increase in the amount of sleep after the acquisition of memories, and the fact that hypocampal rhythms typical of the state of behavioral alert also characterize REM sleep (Ribeiro, 2003).
Recently, it has been demonstrated that the dream process is associated with the decrease of local slow wave activity in the posterior regions of the brain in both the REM and the NREM (Siclari et al, 2018). However, the neurobiology of the dream mechanism still presents several gaps to be filled (Krishnan, 2021).
According to one of the most prominent theories of the origin of dreams, in Hobson & McCarley's activation-synthesis hypothesis, sleep-dreaming would have an adaptive function related to the regulation of emotion, learning and consolidation of memory (Mutz and Javadi, 2017). Presented as a challenge to the psychoanalytic theory about dreams, rejecting psychological interpretations, it is described that in REM sleep, as a result of a decrease in aminergic activity, a disinhibition of the cholinergic system occurs, especially in the bridge (Cheniaux, 2006). Periodically, point-geniculate-occipital (PGO) waves are generated, detected in the REM sleep electroencephalogram on the bridge, propagating to the lateral geniculate body of the thalamus, and then activating the visual cortex (occipital). Thus, based on the visual memory traces stored, the images of the dream are produced (Cheniaux, 2006).
Dreams are seen according to this theory as associations and memories of the cerebral cortex caused by random discharges from the bridge during REM sleep. Chaotic images are formed, which in a second moment undergo a process of synthesis, thus constructing a sequential narrative (Cheniaux, 2006). However, the hypothesis does not explain how random activity can trigger fluent and complex stories that many dreams can contain, nor how it can cause dreams that repeatedly follow night after night (Mutz and Javadi, 2017).
Another theory, of the mesolimbic-mesocortical dopaminergic system and the redemption of Freudian theory was presented by Mark Solms, which is at the same time a critique of activation-synthesis theory and an attempt to confirm Freudian formulation on dreams (Cheniaux, 2006). The dream approach and its experimental results fundamentally challenged the understanding of the dream, proposing that the dream and REM sleep are controlled by different brain mechanisms, in a dissociated way (Ruby, 2011).
REM sleep would be controlled by cholinergic mechanisms of the brain stem, while the dream is mediated by mechanisms of the forebrain that are probably dopaminergic. This implies that the dream can be activated by a variety of NREM triggers. Several experimental results support this hypothesis (Ruby, 2011). The area of the parieto-temporal-occipital junction, would be closely related to the formation of the dream images. Through the ventromedial quadrant of the frontal lobe, fibers of the mesolimbic-mesocortical dopaminergic system pass, which involves the ventral tegmental area of the midbrain, the acumbent nucleus, the hypothalamus, the prefrontal cortex and the anterior cingulate cortex (Cheniaux, 2006).
According to Solms, this system is the generator of dreams and, in its conception, the REM sleep and the dream are controlled by different biological mechanisms: the first, by the cholinergic activity of the bridge; and the second, by the dopaminergic circuits of the previous brain (Cheniaux, 2006). PGO waves often play this role of brain stimulation, but not exclusively. Also according to Solms, the involvement in the generation of dreams of the mesolimbic-mesocortical system, would be related to what psychoanalysis calls pulses, which would confirm Freud's affirmation as to a desire to be the instigator of the dream (Cheniaux, 2006).
One theory is that dreams would have no function. At the end of the 20th century, the neurologist Alan Hobson, profoundly antipsychoanalytic, proposed a theory that stripped the dream of any function (Ruby, 2011). The author argued that the dream is an epiphenomenon of REM sleep, because the difficulty in remembering its content would indicate little significance to survival (Hobso Stickgold; Pace-Schott, 1998).
A current hypothesis of cognitive neuroscience attributes sleep and dream to a role in memory consolidation (Ruby, 2011). Numerous studies have shown that brain activity during training is repeated during post-workout sleep (e.g. using a serial reaction time task) (Maquet et al, 2003). Decreased performance during the post-workout day in sleep-deprived individuals has further suggested that repetition of brain activity at night contributes to memory consolidation (Maquet et al, 2000).
In an addendum to the cognitive function of dreams, there is the Threat Simulation Theory, in which it is postulated that dream consciousness was selected for its adaptive value as a biological defense mechanism, to simulate repetitively threatening events (Scott and Ribeiro, 2010). In it, it is stated that the content of the dream should be, in general, more negative in nature, serving, ultimately, to strengthen the skills of perception of threats in waking state and threat avoidance behaviors that help to deal with the challenging realities of the awakened life (Abbas and Samson, 2023).
The empirical evidence underpinning this theory is the dream selectivity for some types of experiences at the expense of others (everyday cognitive activities are rare in this context), the prevalence of emotions in dreamlike content, and the recurring nightmares that characterize certain conditions, such as Post Traumatic Stress Syndrome (Scott and Ribeiro, 2010).Evolutionary theories suggest that dreams would function as a world simulator of events that would maximize our ability to overcome critical social and threat challenges for survival and reproduction (Abbas and Samson, 2023).
This imagination of the future would use the same neural machinery needed to remember the past, leading to the concept of a "prospective brain", according to which one of the crucial functions of the brain would be to use memories to imagine, simulate and predict possible future events (Scott and Ribeiro, 2010). Dreaming activity would be influenced by the emotional concerns of the vigil, so anticipatory dreams would occur as a function of the psychobiological mobilization around a significant future event (Scott and Ribeiro, 2010).
Some phenomena and influence of external and internal parameters on the content of the dream, such as the link between dream behaviors (appearance of complex motor behaviors when motor inhibition is suppressed during REM sleep) and dream reports, are not yet fully known. In humans, complex motor behaviors (e.g., speaking, grabbing and manipulating imaginary objects, walking and running) can also occur during REM sleep in a pathological context (Ruby, 2011).
Another question is the obscurity about the neurophysiological correlates of dreams. The dream can happen during NREM sleep and although NREM brain activity differs substantially from REM sleep brain activity some NREM dreams are phenomenologically indistinguishable from REM dreams (Ruby, 2011).

Psychoanalytic Theories About Dreams
Psychoanalysis, developed by the neurologist Sigmund Freud in the early 20th century, proposed answers to some questions. Indeed, his theory of the human mind comprises hypotheses on the rules of selection and organization of the representations that make up dreams (Ruby, 2011). In psychoanalysis, the historical rescue of the importance of dreams would be given, by making possible the construction of narratives about the traumatic, creating an intelligible method of dream interpretation through a rational and scientific discourse about dreams and revealing the structures of the human psyche (Roque, 2020).
Studies have been conducted for the expanded use of dream interpretation techniques in all psychotherapeutic modalities (Bulkeley, 2017). One example is the dedication of a growing number of therapists to trauma victims (e.g., combat in time of war, domestic abuse, rape and natural disasters), and many of these therapists are focusing on dream work techniques to help their clients with repetitive nightmares that are a common symptom of post-traumatic stress disorder or PTSD (Bulkeley, 2017).
When Freud wrote the Interpretation of Dreams in 1900 he devoted Chapter 1 to a lengthy review of experimental scientific research on sleep and dreams during the previous 100 years. If a literature review equally complete today, with the aim of summarizing the last century of scientific studies of the dream, it would be written several volumes (Bulkeley, 2017).
In this work, Freud assumed that the main goal of dreams is to preserve sleep; its secondary function is to allow the satisfaction of primitive, repressed, libidinal or aggressive, pulsating desires that push to emerge from the unconscious, although they are unacceptable to our conscious mind (Caviglia, 2021). For this reason, he suggested that such desires are repressed during the awakened life and that dreams have as their function to make possible the discharge of repressed desires (Caviglia, 2021).Freud divided the old theories about the function of dreams into three groups: dreams would represent a continuum of the psychic activity of the vigil, a lowering of that activity or a state in which there is inclination for the development of special psychic activities (Sidarta and Mota-Rolim, 2013).
The result of this complex interaction of forces and defense mechanisms is the manifest content of the dream, but the most important meaning of the dream is hidden in the latent content. The 'real road' to reach latent content are free associations (Caviglia, 2021).
In the early 20th century, Freud presented the concept of the unconscious. He proposed that a part of our mind is made up of thoughts, desires, emotions and knowledge of which we are not aware, but which nevertheless profoundly influence and guide our behaviors. In his books, Freud proposes that the unconscious manifests itself in slips and dreams. Its expression, however, is encoded within dreams (the work of the dream), and unconscious thoughts are distorted before they emerge into the conscious mind of the sleeping subject (manifest content of the dream) (Ruby, 2011).
The unconscious would consist of 3 elements: nocturnal sensory impressions (e.g. feeling thirsty during sleep), daytime remains (records of the events of the eve) and id pulsions (related to fantasies of a sexual or aggressive nature) (Cheniaux, 2006). As a consequence, the dreamer is not disturbed by repressed and unacceptable thoughts (latent content of the dream) and can go on sleeping (so Freud considered dreams the guardians of sleep). These elements of the latent dream tend to make the individual awake. Thus, according to Freud, decoding the latent content of dreams provides an access to the unconscious mind (Ruby, 2011).
In Freud's theory of mind, unconscious thoughts and feelings can cause the patient to experience difficulties and/or mismatches in life, and unconscious free thoughts can help the patient to have a perception of their situation. As a consequence, Freud developed techniques to decode dreams and be a tool that allows the analyst to look inside the patient's unconscious words and images and release them through patient insight. One of these techniques is called free association and is considered an essential part of the psychoanalytic therapy process (Ruby, 2011).
In order for an analyst to reach the latent content of a dream, he requires the patient to discuss the manifest content of the dream and encourage free association over the dream. Free association is the principle according to which the patient must say anything and everything that comes to mind. This includes censoring his own speech so that he actually expresses everything. Over time, the therapist or analyst will make associations between the many uncensored speech sequences that the patient shares during each session. This can lead the patient to a vision of his unconscious thoughts or repressed memories and to the achievement of his ultimate goal of "freeing himself from the oppression of the unconscious" (Ruby, 2011). Thus, Freud considered that dreams, as well as lapses, have a meaning and can be interpreted, so that it is justified to infer from them the presence of contained or repressed intentions (Ruby, 2011).
In other words, according to Freud, the decoding of dreams with the method of free association makes it possible to access what makes each one special, revealing the forces that guide behavior and providing access to an unknown dimension for understanding the individual and personal meaning (Ruby, 2011).
It is important to emphasize that for Freud, dreams would always bring, inscribed in their genesis, hidden meanings related to the desires of the dreamer (Sidarta and Mota-Rolim, 2013).This hypothesis, assigning significant importance and meaning to dreams, was rarely considered by neuroscientists who often consider Freud's work and theory unscientific. However, this situation may change as the relationship between psychoanalysis and neuroscience evolves (Ruby, 2011). Freudian theory is still strongly criticized in academia, mainly because of its poor neurobiological basis (Sidarta R, Mota-Rolim, 2013).
On the other hand, there is the Jungian vision of dreams, which could also provide a synthesis for the debate around continuity versus discontinuity of dream content and awakened life experience (Roesler, 2020). Jung, unlike Freud, assumed the existence of what he calls the collective unconscious which, unlike the individual, would consist of a tendency to sensitize elements such as images and symbols (known as Jungian archetypes), starting from a universal appeal (Roesler, 2020;Hogenson, 2019). Jung's clinical interventions were intended to explore the dialog between the unconscious contents and the archetypes, thus the distance between these elements would be the origin of the psychic illness. From her studies, Jung developed what would later become known as "Analytical Psychology", which investigates dreams, drawings and other materials as pathways of expression of the unconscious (Roesler, 2020).
Analytic psychology believes that the psychic energy behind the images and symbols is called libido, which is actually just a metaphor or operational construction for understanding the psychic processes, or even, the affective bond between the subject and the object outside of it, only indicates the motivation or inclination of this subject towards this object (Serbena, 2010). The ego would be only the part of the psyche responsible for mediation between the outer world and the inner reality, consisting of several levels, starting with the ego, the personal unconscious and then the structures of the collective unconscious (family, ethnicity and humanity) (Serbena, 2010). In the regressive aspect, the perception of the symbol would initially pass through a personal determinant, towards meanings increasingly collective and charged with psychic energy (motivation), until reaching the collective unconscious (Serbena, 2010).
Freud's and Jung's perspectives differ in many respects, as well as with regard to the dream and the interpretation of the dream. Considering that Freud was convinced that the dream has the function of protecting sleep by distorting the unconscious meaning of the dream, Jung saw the dream as a total picture of the current situation of the psyche, including unconscious aspects that he later added that the dream compensates for the attitude of ego consciousness (Roesler, 2020). Thus, Freud sees the dream as covering its meaning, while Jung believes the dream reveals the unconscious.
A specific contribution Jung made to dream theory is that, in dreams, parts of the personality that are not yet integrated or even manifested through conflict (in the sense of complexes), may appear personified (Roesler, 2020). From the Jungian point of view, the interesting question is: what is the relationship of the dream ego, as the representative of the ego complex and the force of consciousness, and these other parts of the psyche? Is the ego in the dream able to deal with these parts or even integrate them or will they appear as a threat to the ego? (Roesler, 2020).
Jung differentiates between a 'subjective' level and an 'objective' level for dreams. In the first perspective, the figures and elements of the dream are interpreted as representing parts or qualities of the dreamer's personality (especially conflicting, i.e. complex, parts), while in the objective perspective, they are seen as representatives of people or entities existing in reality (Roesler, 2020;Wilkinson, 2006). In dreams, the unconscious psyche attempts to support ego consciousness and promote a process of personality integration by pointing to parts of the psyche not yet integrated into the whole personality, or to indicate unresolved conflicts.
Through dreams, the unconscious, by containing a more holistic knowledge about the development and integration of personality, brings new information to consciousness, which can then be integrated, if a conscious understanding of information, being the goal of the interpretation of dreams in psychotherapy. Thus, Jungian interpretation of dreams focuses on the relationship of the dream ego (i.e. the figure in the dream who experiences the dreamer as "myself", psychoanalytically representing the consciousness of the ego) with the other figures in the dream, which gives an indication, through the images, of the ego's ability to deal with emotions, impulses and complexes (being represented in this symbolic form in the dream), and the strength of the consciousness of the ego. As information in dreams comes in the form of symbols and images, it needs translation to be understood by the conscious ego (Roesler, 2020;Vergueiro, 2008).
In an era of psychoactive drugs and cognitive-behavioral therapy, it may seem that therapists in Freud and Jung's deep psychological tradition would have little to say to modern dream scientists, but that would be wrong. Therapists, counselors, and clinicians of various types engage with people in close interpersonal contexts, allowing the emergence of dream reports, discussions, and insights that escape brain scanning and data mining technologies (Bulkeley, 2017).
In psychotherapy, the use of dreams is an important therapeutic tool even for different theoretical models of psychoanalysis, such as the Gestaltic approach or cognitive-behavioral therapy (Scott and Ribeiro, 2010). The hard-won discoveries of psychotherapy teach us empirical truths about the dream that can only be accessed and illuminated from within the interpersonal space created by the healing alliance between the therapist and client (Bulkeley, 2017).

CONCLUSIONS
Dreams are adaptives and learning process, influenced by the social, economic and environmental conditions of the individual's life. The phenomenology of dreaming can be understood by the studies of the theories of psychoanalysis and neuroscience in a complementary and integrated way. There is an connection between neuroscience and psychoanalysis about dreams, which is the driver of new discoveries.
This study presents and discusses the relationship between the dreams studied by neuroscience and psychoanalysis. The dialog between both about dreams is importante for new discoveries: propositions of psychoanalysis have inspired and guided neuroscientific investigations, while findings from neuroscience have been useful for further refinement of psychoanalytic theory. This type of approach is fundamental for a better understanding of the complexity surrounding the meaning of dreams in psychosocial and neurophysiological approches.
This study provides opportunities for future researches. The various elements considered in the literature for the development of this review offer some hypotheses, even that the literature is still insufficient to fully understanding about the neurobiological mechanisms involved in the origin of dreams, their functions and their real dimension about emotions.
The contributions of psychoanalysis is corroborated by biology and experimental psychology, since first observations of Freud and Jung. Psychoanalysis search about the emotional motivations that promote dreams, which have inspired and guided neuroscientific investigations. Thus, an integration of these perspectives is possible and often necessary for progress on understanding the dreams phenomenology.