The slightest touch from our partner can send shivers down our spine and travel through the most erogenous zones of the human body. Repeated stimulation can make our toes curl, our breath short, and our body move rhythmically to this touch. Before we know it, we’ve entered a trance-like state, and orgasm. Researchers at Northwestern University suggest orgasms feel so good because sexual stimulation sends the brain into an altered state of consciousness; it blocks out everything else, and allows us to solely concentrate on the sensation.

"Sex is a source of pleasurable sensations and emotional connection, but beyond that, it's actually an altered state of consciousness" said Adam Safron, study author, a neuroscientist, and a Ph.D candidate in the psychology department's Brain Behavior Cognition program in the Weinberg College of Arts and Sciences at Northwestern, in a statement.

During sex, our brain acts as a “pleasure center” to let us know what is enjoyable and what is not. The various nerves in the genitalia communicate with the brain about the sensation experience; this is why sensations can be perceived differently depending on what part of the body is being touched. The “cloud nine” feeling reported by many during sex is linked to the nerves sent to the brain’s pleasure center, or reward circuit.

Sexual pleasure floods the brain with a surge of neurochemicals — chemical messengers that forge emotions, feelings of attachment, and even love, according Psychology Today. The level of pleasure we feel is connected to the release of the chemicals, which can be used to measure the intensity of our orgasm. The areas of the brain impacted by sexual stimulation include the amygdala, nucleus accumbens, ventral tegmental area (VTA), cerebellum, and the pituitary gland.

In the study, published in the journal Socioaffective Neuroscience & Psychology, Safron and his colleague Victoria Klimaj, reviewed related studies and scientific literature to come up with a model in which rhythmic sexual activity likely influences brain rhythms. The model showed stimulating certain nerves in a particular way at a particular speed over and over again focuses our neurons. They begin to synchronize their activity in a process known as neural entrainment.

Woman Repetitive sexual stimulation can lead to a trance-like state of mind during an orgasm. Photo courtesy of Pexels, Public Domain

Eventually, if stimulation continues long enough, this synchronization can spread throughout the brain, which helps us become more focused than ever. If sexual stimulation is intense enough and goes on long enough synchronized activity could spread throughout the brain. This intense focused attention outcompetes usual self-awareness for access to consciousness, and so produces a state of sensory absorption and trance.

“This then caused me to hypothesize that rhythmic entrainment is the primary mechanism by which orgasmic thresholds are surpassed," said Safron.

The researchers were surprised to find parallels between sexual climax and seizures as well as with music and dance, In both orgasm and reflex seizures, rhythmic inputs into high-bandwidth sensory channels result in an explosive process after certain stimulation thresholds are surpassed. This could potentially be an evolutionary advantage.

The ability to keep rhythm may serve as a test of fitness for potential mates. Safron believes this is consistent as rhythmic song and dances are nearly universal parts of mating; dating back to hundreds of millions of years to our common ancestors with pre-vertebrate animals such as insects.

The trance-like state of mind could also have an evolutionary aspect. For example, the entrainment during sexual stimulation could be nature’s way of saying to continue having sex with this person because they are attending to your sexual needs, which means they’re more likely to be attentive in a relationship.

“Before this paper, we knew what lit up in the brain when people had orgasms, and we knew a lot about the hormonal and neurochemical factors in non-human animals, but we didn’t really know why sex and orgasm feel the way they do,” Safron said

So, this is why sex and orgasms feel so damn good.

Source: Safron A and Klimaj V. Orgasm: Neurophysiological, Psychological, and Evolutionary Perspectives. Socioaffective Neuroscience & Psychology. 2016.