era. In visitation dreams reported in ancient writings, dreamers were largely passive in their dreams, and visual content served primarily to frame authoritative auditory messaging. Gudea, the king of the Sumerian city-state of Lagash (reigned 2144–2124 BCE), rebuilt the temple of Ningirsu as the result of a dream in which he was told to do so. After antiquity, the passive hearing of visitation dreams largely gave way to visualized narratives in which the dreamer becomes a character who actively participates. From the 1940s to 1985, Calvin S. Hall collected more than 50,000 dream reports at Western Reserve University. In 1966, Hall and Robert Van de Castle published The Content Analysis of Dreams, in which they outlined a coding system to study 1,000 dream reports from college students. Results indicated that participants from varying parts of the world demonstrated similarity in their dream content. The only residue of antiquity's authoritative dream figure in the Hall and Van de Castle listing of dream characters is the inclusion of God in the category of prominent persons. Hall's complete dream reports were made publicly available in the mid-1990s by his protégé William Domhoff. More recent studies of dream reports, while providing more detail, continue to cite the Hall study favorably. In the Hall study, the most common emotion experienced in dreams was anxiety. Other emotions included abandonment, anger, fear, joy, and happiness. Negative emotions were much more common than positive ones. The Hall data analysis showed that sexual dreams occur no more than 10% of the time and are more prevalent in young to mid-teens. Another study showed that 8% of both men's and women's dreams have sexual content. In some cases, sexual dreams may result in orgasms or nocturnal emissions. These are colloquially known as "wet dreams". The visual nature of dreams is generally highly phantasmagoric; that is, different locations and objects continuously blend into each other. The visuals (including locations, people, and objects) are generally reflective of a person's memories and experiences, but conversation can take on highly exaggerated and bizarre forms. Some dreams may even tell elaborate stories wherein the dreamer enters entirely new, complex worlds and awakes with ideas, thoughts and feelings never experienced prior to the dream. People who are blind from birth do not have visual dreams. Their dream contents are related to other senses like hearing, touch, smell and taste, whichever are present since birth. Neurophysiology Dream