Dr Alex Kogan, Cambridge University, Dr Gert J ter Horst, University Medical Center Groningen
Falling in love involves a little understood rush of chemicals, including oxytocin and seratonin. But in humans relationships can be formed for decades. We wanted to find out how long this 'honeymoon period' lasts for and how these chemical signals change over time.
Ben - We are still joined Alex Kogan and Gert J Ter Horst. So Alex, how does a reaction to these chemicals change over time?
Alex - Great question. Poorly understood I would say. You know, there's only a handful of studies that have really been done in terms of humans and studying love, in terms of scanner. I'm not really aware of much work in terms for oxytocin, look at levels as they track. We do know that the course of love does peak in terms of the early phase, in terms of this manic, ‘I want to be with you all the time’ phase and then cools off to govern this great state of passion to more companion state as it goes on, and it becomes more tender and more about connection and commitment. But in neuroscience, we’re quite away from really understanding because of all the challenges that are involved in trying to study a topic like this.
Ben - Gert, do you have any idea about how this rose tinted vision that we have during what we call quite rightly the honeymoon period? How does that seem to affect the pathways in our brain?
Gert - How it affects our pathways, I don’t know, but what we’ve done currently is we are measuring using pupil dilation to see how long this period actually lasts and pupil dilation is a measure of our emotions. What we do is we show people a picture of their partner and then we studied them over time and what we’ve seen that it’s probably less or something like ten months.
Ben - Is that all that? It does not seem like a very long time, isn’t it?
Alex - Okay, I’ll take it.
Ben - And sad as it may be to bring up, but what happens at the end of a relationship? Heartbreak can feel like a physical illness. It really hits you hard. Do we know what's going on chemically during that period?
Gert - What chemically is going on? I don’t know, but we’ve just completed an MRI scan for approximately 100 people who have gone through breaking up of a relationship and what we see is a big difference between men and women. In women for example, we find a lot of inhibition in the brain when they're confronted with a photograph of their ex-partner which is significantly less in men. What we also see is that women suffer greatly from heartbreak really at the beginning and after 6 months, this wears off, and in men, we see the opposite. They start rather happy after a breakup, but they end up in a serious breakup problem after about 6 months.
Alex - Do you know how that also maps onto maybe the different roles of being the breakup-er and the breakup-ee? Because you can imagine the person that's doing the breaking up initially feels relief, they're great. I got into this relationship I wasn’t happy about and I have the initial boom and then later on, they realise, well, wait there were all this wonderful things I had that are now gone whereas for the breakup-ee, they get hit with the misery right away, but maybe they could start the healing process a little earlier.
Gert - Yes, we also studied that aspect, but since we have not yet completed the study and we were running the final analysis right now, I cannot really discuss this yet.
Ben - Well, on a more positive note, do we know what changes occur that help people to stay together? Do we see particular patterns of brain activity in couples who have been together for a very long time?
Alex - I suppose there is some evidence from animal models where again, the prairie voles, in terms of distribution of say, the vasopressin network or the oxytocin network. So, we could say those systems are likely involved, but the work with humans is early. The first studies really with humans with oxytocin generally begin until the 2000s I would say, picking up with nasal sprays. And so, I think we’re so really trying to figure out what happens in a moment and we haven’t really started to touch on a lot of these more interesting longitudinal effects.
Ben - It seems surprising to me that something that has concerned mankind for all eternity, is something that we’ve only recently started studying.
Alex - It’s funny you mentioned that because pre-1970s, there was really almost no research in psychology on love. Zick Rubin was one of the pioneers who started the work and during his dissertation, they said, “Well, why are you studying this? Nobody has done it.” He said, “Well, the lit review could be very short” and now, it’s much longer because there's been a lot more work done, but it’s so complex. A lot of the work is often – well, we need to narrow the scope, not study love of everything which will include cheesecake, but I will study just the passionate love which is a very particular type of romantic love of companionate love or unconditional love, and it’s one of the most complex topics that we know of.
Gert - And we have to do longitudinal studies as well to follow people because that has not been done yet.
Alex - Yeah, not at all.
Ben - And just quickly, Gert, we were talking about dopamine earlier. We know that dopamine, as well as being involved in reward, it’s very frequently evolved in addiction. Do we think it’s possible that long term relationships may just be a case of being addicted to each other?
Gert - This has been studied in one MRI study in the US where they showed that people who were still in love after 25 years and happily in love, so they claim they were as much in love as when they just met, and these people, they have a pattern of brain activity that resembles addiction, so it could be.
Ben - So, it really could be that we are just simply addicted to one another. I think that's quite a nice way to end and of course, Robert Palmer said that “You're going to have face it. We’re addicted to love.” That was Alex Kogan from Cambridge University and Gert J Ter Horst from the University of Groningen.