46 | New Scientist | 14 September 2019 felt – all of which chimes with Ian’s
descriptions of gaming. The image of an
addict’s world shrinking is not just a metaphor;
their field of vision literally narrows, until
their addiction is all they can see.
Before gambling and gaming disorder were
accepted as behavioural addictions by the
WHO, they were included under a different
category, impulse control disorders. Last
June, a new impulse control disorder was
added to the list: compulsive sexual behaviour.
According to Valerie Voon, a psychiatrist
and neuroscientist at the University of
Cambridge who researches sex addiction,
it is just a matter of time before there is
enough evidence for its inclusion in the
behavioural addiction category.
She and her colleagues designed a study
to see what happens in the brains of possible
sex addicts when they watch pornography.
Nineteen heterosexual men with a diagnosis
of compulsive sexual behaviour and 19 men
with no history of addiction were shown
pornographic and less sexually arousing
videos while having their brain activity
scanned using functional MRI.
In earlier studies, when people addicted to
substances were exposed to the cue for their
addiction, be it cigarettes, alcohol or drugs,
brain scans showed activity in three specific
regions: the amygdala, the ventral striatum
and the anterior cingulate cortex, areas
associated with the reward system.
In the study Voon led, there was an increase
in activity in those same three regions in
the brains of the participants with signs
of addiction to sex when they watched the
pornographic videos and not in those of the
Somewhere between 15 and 20 per cent of us would develop an addiction if we were exposed
