Why Do Healthy Men Experience Morning Erections?

Abstract

Abstract:People begin the sleep cycle with a period of non-rapid eye movement (NREM) sleep, followed by a very short period of rapid eye movement (REM) sleep. During a normal night of sleep, humans usually experience about four or five periods of REM sleep. Penile erections have generally been considered to be an epiphenomenon of REM sleep-related physiological changes for healthy males. Thus, men are very likely to awaken in the morning with a REM sleep-related erection, which is also known as nocturnal penile tumescence (NPT). Men who are physically under great strain or serious psychological stress may find it difficult to maintain a psychogenic erection. The best time for them to have sex would be during sleep time, such as when they are experiencing REM sleep-related erections. It is reasonable to assume that the NPT phenomena might have evolved as a tool for having sex, in the context of both procreation and recreation.Keywords : REM sleep, Morning erection, Nocturnal penile tumescence, Sexual intercourse, Procreation, Recreational sex. REM SLEEPMammalian sleep consists of natural cycles of activity in the brain and has distinct states: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep which consists of Stages 1 through 3 [1]. Typically, people begin the sleep cycle with a period of NREM sleep followed by a very short period of REM sleep. Dreams generally occur in the REM state of sleep [2,3]. Usually, REM sleep occurs 90 minutes after sleep onset. The first period of REM typically lasts 10 minutes, with each recurring REM state lengthening, and the final one lasting up to an hour. That is, the proportion of REM sleep in total sleep time in humans increases as morning approaches. During a normal night of sleep, humans usually experience about four or five periods of REM sleep. REM sleep in adult humans occupies approximately 20-25% of total sleep, or about 90-120 minutes. Some people tend to wake, or experience a period of very light sleep, for a short time immediately after a bout of REM [2 -6].There are many theories about the functions of REM sleep, but they are not understood well. It has been hypothesized that the REM state serves a sentinel function, bringing about a brief, but periodic, awakening after preparing the organism for immediate fight or escape [7,8]. That is, REM sleep activates an animal periodically to scan the environment for possible predators. Such a built-in physiological mechanism presumably would provide maximal security from external danger compatible with minimal disturbance to the continuity of sleep. Apparently, humans are more alert when aroused from REM sleep than NREM sleep [2,8,9]. Many researchers argue that REM sleep serves an important function for the survival of mammalian and avian species. In both humans and experimental animals, REM sleep loss leads to several behavioral and physiological abnormalities [2,8,10,11]. In addition, some researchers state that REM sleep may function to influence and promote social bonding or attachment in the develop...

‘Staying Hot’: Investigating the influence of overnight conditions on the penile skin temperature during male sexual arousal—A novel methodology for nocturnal erection detection

“…To assess the capability of detecting erections under overnight The data of this study was collected through measurements of visually aroused erections, which result from different physiological processes compared to nocturnal erections. 19 Nocturnal erections typically last an average of 25 min, 20 whereas the recorded erection duration in this study was 8.78 min, falling short of the intended 10-min duration stated in the literature as the time required to reach peak temperature during an erection. 8 Test subjects reported that the pressure to achieve a visually aroused erection in combination with the excitement about participating in the study led to difficulties in adhering to the anticipated erection duration.…”

“…The data of this study was collected through measurements of visually aroused erections, which result from different physiological processes compared to nocturnal erections 19 . Nocturnal erections typically last an average of 25 min, 20 whereas the recorded erection duration in this study was 8.78 min, falling short of the intended 10‐min duration stated in the literature as the time required to reach peak temperature during an erection 8 .…”