April 20, 2012 report
Experiment shows visual cortex in women quiets when viewing porn
(Medical Xpress) -- Researchers from the University of Groningen Medical Centre in the Netherlands have found that for women at least, watching pornographic videos tends to quiet the part of the brain most heavily involved in looking at and processing things in the immediate environment, suggesting that the brain finds arousal more important during that time than is processing what is actually being seen. The team has published a paper in The Journal of Sexual Medicine describing their findings.
To find out if the primary visual cortex is essentially deactivated during sexual arousal in women, the team enlisted 12 volunteers; all women between the ages of 18 and 47, who had not yet reached menopause. Also each was on oral birth control pills which tend to flatten menstrual cycles and smooth out sexual desire and/or anxiety. Each was shown three videos, one with no sexual connotation, another with mild sexual content, and a third that was full on hard-core porn. While they were watching the videos, the women were also having their brain activity watched via PET scans, which work by measuring blood flow to the various brain regions. It is thought that more blood flow indicates that more brainwork is occurring, which implies that when the brain delegates tasks to different regions, by sending more blood, it is demonstrating that it finds certain activities more important than others.
The team found virtually no difference in brain activity in all of the women when watching the first two videos. When watching the third however, they found that blood flow to the visual cortex was reduced in all of the volunteers indicating that the brain had decided that focusing on arousal was more important than fixating on exactly what was occurring on the screen in front of them (or that women just don’t want to really see what is going on with sex). This is in direct contrast to most other visual activities which tend to cause more blood to flow to the visual cortex to process all of the information that is coming in.
The researchers also suggest their findings help explain why women who exhibit symptoms of anxiety often report sexual problems, as high anxiety is often correlated with increased blood flow to the visual cortex due to the person reacting on a nearly constant basis to visual stimuli. They point out that for people in general, the brain cannot be both anxious and aroused, it generally has to be one or the other, or neither.
© 2012 Phys.Org