Saturday, February 23, 2008

Romantic love and madness

Many, especially in the media, have commented about the work we published in 2000, showing the pattern of activity in the brain when those who are "madly and passionately" in love view a picture of the one they love. But there is another aspect of these results which is just as interesting, and which has received much less attention and comment. I refer to the fact that, under the same conditions, that is when a lover views the picture of the one he or she is passionately in love with, large parts of the brain, and particularly in the frontal lobes, become de-activated. The frontal lobes are of course those parts of the brain which have been traditionally associated with higher cognitive functions, including judgment. The clear implication is that judgment is more or less suspended, or at least much attenuated, when we are confronted with the one we love passionately.

In a sense, of course, this is a formal demonstration of what many have written about - the madness of love. We often ask someone who is passionately in love with a person whom we disapprove of: "Have you taken leave of your senses?" Well, in fact they have. And hence it is commonly, though not always, futile for disapproving parents and friends to try and prevent a liaison. The pattern of activation in their brain renders them less judgmental of the person they love than of others. The qualification is critical, for judgment is not suspended; it is only judgment about a particular individual that is suspended, implying a very selective brain procedure where judgment is concerned.

Here then is a possible neural basis for the "madness" of love that poets and writers since the time of Plato have written about. Nietzsche once wrote: "There is always some madness in love. But there is always some reason in madness". Perhaps the "reason" is to be sought in the pattern of neural de-activation that we have observed.

Of course, this pattern of activation is the one observed in the early and passionate stages of romantic love, a stage that usually does not continue indefinitely. One presumes that when a relationship becomes stabilized, or indifferent or even hostile, then the de-activation that is so prominent a feature of the passionate phase of love is no longer evident. It would be interesting to pursue such a study. It is now clear that there are chemicals, among them nerve growth factor, whose concentration rises during the early and passionate phase of romantic love, only to drop to normal levels once the relationship is stabilized or ended.

Nor is this suspension of judgment unique to romantic love. In a further study of the brain's love system, we studied the neural correlates of maternal love. The pattern of de-activation was remarkably similar to the one observed in romantic love, again leading one to believe that this constitutes the neural basis of the suspension of judgment - after all, mothers tend to be far less judgmental about their own children than about other children.

These are small steps in learning about the neural basis of love. There are other interesting discoveries to which I will return later.