The neuroscience of mediation
It’s time to crack open some naked neuroscience news, with friends of the show Helen Keyes and Duncan Astle. And perceptual psychologist Helen is on a bit of a couples theme at the moment. Last month, it was brain synchronisation among couples who sleep together, and this month it’s about what’s going on at a neural level when we get into an argument with a significant other. Helen explained that there’s quite a lot known about good and less good ways of arguing with a partner in terms of conflict resolution, and that there’s also a fair bit known about the brain activity observed when we look at a partner, so this new study set out to marry up the two...
Helen - They recruited 36 heterosexual couples. So the couples were going to be involved in a conflict or an argument and half would have a mediator there. So someone who is trained in couples counseling to kind of structure the discussion and the argument, manage negative emotions if they're are getting out of hand, redirect people towards more positive and focused aspects of the argument. All couples would, first of all, complete questionnaires about the quality of their relationship and the level of disagreement within their relationship in general, the level of closeness and things like how mindful they were as people and their current mood. After that, one member of the couple - so this is before any argument - would go into the fMRI machine and be shown images of their partner's face. They would also be shown images of a stranger's face. Now the stranger would be the same gender as their partner. Their brain activity would be monitored in the fMRI machine while they looked at their romantic partner and the stranger, and they would also be asked to rate, using smiley and unhappy faces, how they felt after seeing an image of their partner or the stranger.
So following this is when the conflict happens. The couples engaged in basically an argument around some common point of conflict in their relationship, of which I'm sure there were many to choose from for long established couples! And this was either mediated by a professional for half of these couples, or it was an unmediated discussion. Now for the un-mediated discussion, a third person was present in the room, but remained silent and didn't structure or manage the conversation.
Katie - Is that to control for, say, if you wouldn't actually say something if someone else was there, you might be a bit embarrassed to, I don't know, shout at them or something like that.
Helen - That's exactly what it was for. Absolutely. The couples then completed questionnaires about how satisfied they were with the session. So did they feel the conflict resolution worked, was the conflict resolved, and how much disagreement was remaining? Then the person who initially went into the fMRI machine went back in and their brain activity was again monitored while they again saw images of their romantic partner and images of a stranger.
And what they found was behaviourally the mediation by the third party lead, not surprisingly, to a greater number of agreements between couples and in a reduced level of disagreement at the end of the conflict session. That's not that surprising.
Looking at the fMRI, what was interesting was that in general, across both groups, whether you'd had a mediated or unmediated conflict, there was decreased activation in the areas associated with romantic love, when you saw your partner's face. However for the mediated group, they had greater activation in one particular area of the brain that's really associated with our reward circuitry, compared to those who hadn't been in a mediated discussion.
Katie - Is this basically showing that mediation is very effective, actually?
Helen - It is showing that. Well it's showing a few things. It's showing that conflict with your partner is likely to be damaging to your representation of your partner or how you view them. But conflict isn't obviously always avoidable. And this is showing that mediation does seem to have a genuinely beneficial effect. That's not just an effect that we observe in terms of couple satisfaction, but we can also see on a neural level that people are still maintaining that reward response when they see their partner following mediated discussions, but not un-mediated discussions.
So if we're thinking about what's going to help couples in resolving conflicts, it's not just about somebody else being there, or having a shoulder to cry on ,or somebody listening, or a third party. It's about a trained professional able to structure that argument and that discussion and manage those negative emotions. That seems to be what's having the positive effect.
Katie - Which bit of the brain was it that was particularly distinctive in this?
Helen - It was the nucleus accumbens. And that's part of the basal ganglia near your hypothalamus. And it's largely associated with reward circuitry in your brain.
Katie - You mentioned all the couples were heterosexual. Were there any differences, say if it was the female person in the fMRI compared to the male person?
Helen - They didn't record any differences between genders, which was quite interesting in and of itself.
Katie - Because I was just wondering whether there would be any reason to suspect that you might see anything different if the couples were of other orientations?
Helen - I don't know. And I think it's a big pity in psychological research that we tend to use what is deemed to be the majority of the population. So for example, in this study even, they only use right-handed participants. And they only used heterosexual participants, and they only used people with normal vision or corrected-to -normal vision. It's an odd feature of psychological research that they think they will do the most benefit by testing people who are what they would consider to be the most normal representation of society. But it has obviously damaging effects and can really miss out on key areas of the population.
Katie - Duncan. What do you make of this study as Helen's explained it?
Duncan - I wonder about individual differences. I know they haven't got that many subjects in this study, but you can imagine that this is the kind of thing that would be really variable across individuals and across couples.
Helen - Yes, there is really well established variability in this, depending on individual differences, but also quality, length, strength, depth of your relationship. So, not in this study here, but in other studies on what areas of the brain are activated and how strongly when you view pictures of your romantic partner, these links are already really well established.
Cognitive neuroscientist Duncan Astle has been mulling over memory for us this month…
Duncan - Well, Katie, we're all getting older. Some days it feels more rapid than others, I'm afraid to say! But as we do age, one thing that changes is our memory. And one particular type of memory that changes is episodic memory. It's partly supported by a structure in the brain called the hippocampus. You have two, one in each hemisphere. And in this study, they were interested in how episodic memory changes as people get older and how the brain mechanisms that support episodic memory change as people get older. So episodic memory is what we call a type of explicit memory. Something that you're consciously aware of. And it's usually memory for events or episodes that have happened to you. For example, what you had for breakfast or where you parked your car. These memories can often last for relatively short periods of time. So a few minutes or hours or potentially a lifetime. And they can be distinguished from other types of memories, like semantic memories. So for example, that Paris is the capital of France. So at some point that was an episodic memory. Someone told you the first time, but over time it became a semantic memory. So those are the two main forms of long term memory.
Katie - I would assume that episodic memory gets worse with age. Is that just the stereotype or is that true?
Duncan - Indeed it does. But the question is whether the same brain mechanisms support episodic memory, as you get older as they do when you're younger. So in this study, they recruited two groups, a sample of people who on average are around 70 years of age. And another group who were on average around 23 years of age. They were both put inside an fMRI scanner and they were shown particular items like "barn" or "door", which they were instructed to remember. Then they had a period where they had to try and recall them. So they would show a label and they had to bring to mind the item and rate how confidently they were able to retrieve it. And then later on, they actually showed people examples of barns to see if they could pick out the exact one that they'd been shown.
All the time, they're scanning their brains. And in particular, during the retrieval phase, they looked at brain activity within multiple different brain areas. And in particular, they looked at activity within the hippocampus and also the prefrontal cortex, which is right at the front of the brain. And what they wanted to explore is whether or not the prefrontal cortex is kind of kicking in as you get older, to support your failing hippocampus.
Katie-Oh, okay. So some sort of compensation going on?
Duncan - Exactly. So some people have shown already that on these kinds of tasks, older subjects have increased activity in the prefrontal cortex relative to younger subjects. So one argument that's been made is that that's because they're doing it to compensate, but it's quite hard to demonstrate that explicitly. And that's what this study set out to do.
So to start with, they're able to show the older individuals did indeed show stronger prefrontal cortex activation, but they went a step further and they constructed what's called a connectome. So that's where you estimate the extent to which different brain areas are functionally connected with other brain areas. And what they're able to show is during this retrieval phase, the older subjects' prefrontal cortex was more strongly integrated with other nodes within the brain. So it wasn't just more active. It seemed to be more plugged in to activity elsewhere in the brain. And those subjects for whom the prefrontal cortex was most plugged in, were the subjects who did best on the task. So that would be consistent with the idea that it's somehow compensating.
Katie - Does that have any additional relevance? Because I tend to think of memory as something that fails or sort of weakens relatively as we get older. But the brain being more connected with other bits sounds like an advantage.
Duncan - Ah, we'll get onto that in a moment, but yeah, you're right. The final piece of the puzzle is to demonstrate that you get these sorts of systematic increases in prefrontal cortex integration, as you get drops in hippocampal integration. And that was what they finally showed, is that you get this sort of prefrontal cortex stepping in, in the older adults, more so as the hippocampus sort of steps out as it were. Which is sort of the direct evidence of the kind of functional compensation account.
Now you are asking about "surely, that's a great thing?". It's a compensation strategy that probably works to some extent early on, but if you were to start to experience much more progressive hippocampal damage, for example, like say in the case of a dementia, then what you might well find is that as that damage becomes more extensive, the prefrontal cortex would no longer be able to compensate.
Katie - Does this transition on which bits of the brain are being relied upon for this memory, does that have any practical difference to the quality of the memory? Would you be able to tell?
Duncan - I think in this task, probably not, cause it's such a basic task. But one thing you notice with subjects who do have episodic memory problems - so for instance, mild cognitive impairment or something much stronger like Alzheimer's - is in the very early phases, what subjects or what patients are able to do is sort of fill in the gaps. So the prefrontal cortex we know is an area of the brain that's specialised for highly flexible thinking and problem solving. And so what people are possibly doing is rather than sort of remembering the exact episode, they're maybe remembering little bits and then they are sort of filling in the gaps with this sort of more flexible brain system, the prefrontal cortex system. And so I suspect that ultimately it will result in a loss of quality of the memory, or it's indicative that the quality of the memory is lower. And that's why the prefrontal cortex is having to step in.