Why does lust turn guys into idiots?

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The best I could find on such a short notice, was a study on romantic and maternal love (not lust exactly, but the study deals with that as well), done by a British neurobiologist Semir Zeki.

In broad strokes, their study reports to have found that the state of romantic love is characterized by a pattern of activation and de-activation of certain brain areas; and is associated with an increased expression of neuromodulators dopamine, oxytocin, and vasopressin, and a decreased expression of serotonin in certain key areas.

I pulled some excerpts for a quick overview:

Both deactivate a common set of regions associated with negative emotions, social judgment and ‘mentalizing’ that is, the assessment of other people’s intentions and emotions. Human attachment seems therefore to employ a push–pull mechanism that overcomes social distance by deactivating networks used for critical social assessment and negative emotions, while it bonds individuals through the involvement of the reward circuitry, explaining the power of love to motivate and exhilarate.

And the areas that are activated in response to romantic feelings are largely co-extensive with those brain regions that contain high concentrations of a neuro-modulator that is associated with reward, desire, addiction and euphoric states, namely dopamine.

Studies have shown a depletion of serotonin in early stages of romantic love to levels that are common in patients with obsessive-compulsive disorders. Love, after all, is a kind of obsession and in its early stages commonly immobilizes thought and channels it in the direction of a single individual.

The early stages of romantic love seem to correlate as well with another substance, nerve growth factor, which has been found to be elevated in those who have recently fallen in love compared to those who are not in love or who have stable, long-lasting, relationships. Moreover, the concentration of nerve growth factor appears to correlate significantly with the intensity of romantic feelings.

Oxytocin and vasopressin expression also is increased:

The concentration of both neuro-modulators increases during the phase of intense romantic attachment and pairing.

Moreover, sexual arousal (and orgasms) de-activate a region in the frontal cortex that overlaps the de-activated region observed in romantic love. This is perhaps not surprising, given that humans often take “leave of their senses” during sexual arousal, perhaps even inducing them to conduct which they might later, in more sober mood, regret.

Among these are connections with the frontal, parietal and middle temporal cortex as well as a large nucleus located at the apex of the temporal lobe, known as the amygdala. Increase in activity in the romantic core of areas is mirrored by a decrease in activity, or inactivation, of these cortical zones. The amygdala is known to be engaged during fearful situations and its de-activation, when subjects view pictures of their partners as well as during human male ejaculation, implies a lessening of fear.

As well, the all-engaging passion of romantic love is mirrored by a suspension of judgment or a relaxation of judgmental criteria by which we assess other people, a function of the frontal cortex (Fig. 3). This cortical zone, along with the parietal cortex and parts of the temporal lobe, has also been commonly found to be involved in negative emotions. Its inactivation in romantic as well as maternal states – when faced with the loved one – should not therefore be surprising because, when deeply in love, we suspend those critical judgments that we otherwise use to assess people.

Full text can be found here:

http://www.sciencedirect.com/science/art...9307004875