“The dream and its subsequent emotional interpretation have been studied and recorded since the beginning of recorded history.” (as cited in Palagini; Rodenlicht, 2010). Recent experimental research applied to neurobiological and psychological perspectives of sleep identifies a highly dynamic state of wakefulness, which in turn predicts various physiological responses. One of the key stages associated with sleep is known as REM (rapid eye movement) sleep; At one time, REM sleep was considered the primary dream period. However, recent research and empirical evidence have shown that REM sleep has no direct relationship with dreaming, yet it is purely and simply the stage of sleep that allows for better dream recall. This is supported by Nielson (2000) who presented empirical evidence that dream recall during REM sleep in adults reached 60–90% after waking, whereas when individuals transitioned into NREM sleep, this recall decreased significantly. up to 25 to 50%. Throughout this report, the importance of REM sleep in the period of analysis of these hallucinatory events will become clear. It is also important to clarify the different concepts and approaches attempting to explain the dream phenomenon, such as psychoanalytic, neurobiological and finally evolutionary explanations. Sigmund Freud (1922) “The dream is the royal road to knowledge of the unconscious in mental life” (as cited in Arnold; Vogal, 2007, p20-21). Freud became adamant that dream symbols and interpretations as they relate to psychoanalytic perspectives will always be prevalent and will never be refuted. The methodology of psychoanalysis reinforces the idea that the analysis of dream content is a vital necessity for the individual...... middle of article ......inel, P, JJ (2009 ) Biopsychology. United States: Pearsons Education Inc. Sigmund....Sue, L. (2011). If waking and dream consciousness became dedifferentiated, would schizophrenia result? Consciousness and Cognition, 20(4), 1059-1083. Valli, K. and Revonsuo, A. (2006). Recurring dreams: simulations of recurring threats? Consciousness and Cognition, 15(2), 464-469. Valli, K., Revonsuo, A., Pälkäs, O., Ismail, KH, Ali, KJ and Punamäki, R. (2005). The threat simulation theory of the evolutionary function of dreams: Evidence from the dreams of traumatized children. Consciousness and cognition, 14(1), 188-218. Vedfelt O. (1999). The Dimensions of Dreaming: New York: Fromm International Publishing Corporation. Wegner DM, Wenzlaff RM, Kozak. M. (2004) Dream Rebound: The return of repressed thoughts in dreams. Psychological Science 15(4), pp... 232-236.