Volume 1, number 2

Radiology
Sexual impulses under observation

The seat of temperance exists. It is located in the prefrontal lobe of the brain. The discovery was made by neuropsychologist Mario Beauregard during an experiment conducted in his laboratory on 12 men aged 20 to 30 years whom he asked to control their sexual excitation while watching erotic films. "It is very clear," notes the researcher. "The images of the brain in action obtained by magnetic resonance show intense activity in the prefrontal lobe."

Temperance ("moderation in action, thought, or feeling" according to Merriam-Webster), or more precisely, the control of sexual excitation, is controlled by an organ that is specific to primates and highly developed in humans. The prefrontal lobe of the brain is the last part of the nervous system that developed during evolution. Chimpanzees have a prefrontal lobe, but it is no more than 25% the size of the organ in its humanoid cousins.

In comparison, zones activated when the volunteers gave free rein to their impulses when viewing erotic scenes were located in the more "primary" zones. The limbic system (region of the brain that includes the hippocampus, the septum and the amygdala, sometimes called the emotional brain) reacted very strongly during X-rated scenes, while the prefrontal cortex was more or less quiet.

The results of Professor Beauregard's work, conducted in conjunction with a Université de Montréal doctoral candidate and a researcher, Johanne Lévesque and Pierre Bourgouin, will be published shortly in a major review, the Journal of Neuroscience. The article specifies that "self-control is seated in a neuronal circuit comprising different prefrontal regions and limbic structures."

After completing post-graduate work at the National Institute of Health and the Montréal Neurological Institute and a Ph.D. at Université de Montréal, at 39 years of age, Mario Beauregard has barely embarked on a research career in the field of medical imaging. He has always been curious about the relationship between the mind and emotions. "What interests me, is imaging the brain in action, how mind and consciousness are expressed in neurological terms." Will researchers manage to see the human soul? "At any rate we see how neuronal circuits act during different activities when emotions and self-control come into play," he answers.

Researcher : Mario Beauregard
Phone : (514) 340-3540, ext. 4129
Funding : Natural Sciences and Engineering Research Council of Canada (NSERC)