"The five-minute movie shows how activity changes across 80 separate regions of the brain in snapshots taken every two seconds. The animation uses a "hot metal" colour scale that begins at dark red and progresses through orange and yellow to white at the highest levels of activity. "The general aim of this research is to understand how the orgasm builds up from genital stimulation and what parts of the brain become recruited and finally build up into an orgasm," said Prof Komisaruk, who presented the work at the Society for Neuroscience annual meeting in Washington DC on Monday. The work has yet to be published in a peer-reviewed journal. As the animation plays, activity first builds up in the genital area of the sensory cortex, a response to being touched in that region. Activity then spreads to the limbic system, a collection of brain structures involved in emotions and long-term memory. As the orgasm arrives, activity shoots up in two parts of the brain called the cerebellum and the frontal cortex, perhaps because of greater muscle tension. During orgasm, activity reaches a peak in the hypothalamus, which releases a chemical called oxytocin that causes pleasurable sensations and stimulates the uterus to contract. Activity also peaks in the nucleus accumbens, an area linked to reward and pleasure. After orgasm, the activity in all these regions gradually calms down."