The regulation of three hormones in the human brain is being discussed this week, while notices appear of new fictional works about virtual lust: a novel, a film and a computer game.

They concern hormones that tell the human brain how to feel about lust, and some would say, love. And like many drugs, lust shows characteristics of addiction: higher doses are needed after prolonged use, users become dependent, withdrawal gives unpleasant symptoms, and they want to relapse after abstinence.

Dopamine stimulates euphoria and happiness (so unsurprisingly, does cocaine) –

Serotonin is an anti-depressant which can make loving difficult. What’s more, low levels of the hormone are found in patients with Obsessive Compulsive Disorder and in people deeply in love –

Oxytocin induces feelings of attachment and faithfulness to another; there are low concentrations in mammals that behave polygamously.Some pharmacologists have even suggested that love comes to an end when oxtocin levels fall below a certain level –

The meaning of these biochemical responses is not lost on the three latest creators of virtual art. One is the writer D Levy with Love and Sex with Robots.

            Then there is Jonze’s 2014 film Her, telling what happens when a man falls in love with a computer operating system.

Also recently, in Japan, a man has publicly betrothed Nene, a character in the 2006 Nintendo game Love Plus.

(H.Fisher, A. Aron, L. Brown, 2005: Romantic Love: An fMRI Study of a Neural Mechanism for Mate Choice J. Comp. Neurology 493:58-62. D. Marazziti, H.S. Akiskal, A. Rossi & G.B. Cassano, 1999: Alteration of the platelet serotonin transporter in romantic love, Psychological Medicine, 29,741–745. Graphics with thanks to Wikipedia.)