Both men and women experience erections (male penis, female clitoris) during sleep or upon waking. Testosterone levels are highest just before sunrise, with lowest levels occurring about 11pm. (Stump, Jane Barr, PhD. What’s the Difference? p 73-74. NY: William Morrow and Company, Inc., 1985.)

Males can find it difficult to speak, hear, or drive when they have an erection. Males use the right hemisphere during sex. Brain scans show the male is virtually deaf during sex due to his goal-oriented undistractability. (Pease, Barbara and Allan. Why Men Don’t Listen and Women Can’t Read Maps. p 73-74. NY: Broadway Books, 1998.)