Exploring the science of changing behaviours and the brain-based systems which direct how we act…
15 March 2022
Presented by Julia Ravey, Harrison Lewis
Production by Julia Ravey.


Ever set a new year's resolution only for it to fall by the wayside after a few weeks? It is common for us to have goals and want to make change, but when it comes to turning those plans into reality, it can feel difficult. We often default back to old routines as more common behaviours take hold. Alongside trying to find ways to help us stick to our resolutions, we are exploring how our brain decides which way to act, how behaviours transition from being goal-directed to habitual, the disorders which can arise from alterations to these systems, and how research is trying to find methods to help us make the changes we want…

In this episode

Refugee crisis

01:03 - How war impacts the spread of infections

With millions fleeing Ukraine, the threat of COVID-19 outbreaks amongst refugees looms…

How war impacts the spread of infections
Kate White, Médecins Sans Frontières

Two weeks into the war in Ukraine, we've seen heart rending footage of people fleeing the Russian attack with what little they can carry. Quite rightly, the reporting has focused heavily on what's happening to people and where they are going. But one issue that's not received much media attention is the question of infectious dieases. Conflicts always breed outbreaks, and packing people together in evacuation, refuge or shelter settings is the perfect opportunity for diseases to spread. Although it's fallen off the front page, Covid-19 has not gone away and rates of vaccination uptake are low in eastern Europe. The region is also a hotspot for drug resistant TB. Chris Smith spoke with Kate White, who's the head of the emergency unit at Médecins Sans Frontières...

Kate - In Ukraine, prior to this conflict, there were quite low vaccination coverage rates in terms of routine immunisation, and also in relation to COVID-19, which means that this population has a higher risk of contracting some of those diseases.

Chris - Do you know what the vaccination rate was for COVID?

Kate - It was roughly around 35% of the population. That's extremely low.

Chris - That means then that if we've got lots of people being corralled together in packed railway carriages, in underground shelters, and then in refugee centers, that there is the potential brewing for a big outbreak here.

Kate - Yeah, there is. But it is extremely difficult for people to deal with that in those really tight closed settings. They don't have the opportunity to take the measures that everybody talks about in relation to COVID. In many places, people are struggling to meet their day to day needs, let alone be able to reinforce those measures as well.

Chris - What measures are being put in place then? Or have people not realised they need to grasp this net and they need to do it quickly to make sure that we don't let these diseases, including COVID, escape?

Kate - It's more a case of the system has just been so incredibly overwhelmed right now. For example, in Poland, there is approximately 140,000 to 150,000 people crossing the border every day. That is 3x more than the peak that they experience in summertime holidays. If you can imagine just every day that shear stress on the system, it's not had time to put in place anything that's going to help prevent some of this. And then from an individual perspective, when you've had to leave your home and flee extremely fast with what little possessions you can, prevention of illnesses like COVID falls way, way, way down on your priority list. Trying to get a system in place that can encourage people to put that somewhere on their priority list and make sure that we're able to have that prevention for transmission is really important, but it's going to take a little while to be able put that in place.

Chris - One of the other big issues is that, previously, the World Health Organisation has earmarked Ukraine and the environs of Ukraine in Europe as one of the hotspots in the European region for TB. That spreads the same way; packed surroundings, lots of people in close proximity under extreme stress. That's a longer term challenge that we need to worry about as well.

Kate - There's two elements to that. I will start with the somewhat easier one, which is for those people who were already on treatment. In terms of Ukraine, one of the factors around TB was that there were many cases of drug-resistant TB. The regimen that people were previously on is really important to maintain. The good part about being on TB drugs is that even though you might not have finished your course and be cured, once you have been on the drugs for a certain period of time, about a week, you actually very significantly drop the ability to transmit TB to other people. Making sure that that group of people still has access to the specific drugs that they were on is really, really important.

Chris - Is someone worrying about that? Is that actually a priority? I haven't seen that documented in any newspaper, in any medical paper, any medical writings, someone saying, 'look, we've got a part of the world where there's a really high TB rate with drug resistant forms of this disease. There's going to be a lot of people who can't access their normal medicine. We need to sort that out.'

Kate - I think in terms of what's publicly out there, it's probably not a conversation that you see a lot; mostly because it's not the sexy news or the sexy response to this crisis. But amongst the health community that is engaged in this response, it is very much a conversation that is happening. They're just not getting the media coverage because most people are not interested.

Chris - Luckily we are.

Kate - The second element is obviously for those who have not yet received a diagnosis. For them what's really important is that we have good routine screening of people.

Arctic ship wreck

06:51 - Endurance discovered intact after a century

The story of the lost vessel, which was recently found on the Antarctic sea floor…

Endurance discovered intact after a century
John James & Adrian Glover, Natural History Museum & Mensun Bound, Oxford University

As we speak, the research vessel S.A. Agulhas II is steaming back to port. Aboard is an international expedition tasked with finding the wreck of the ship Endurance. The project is led by John Shears, with over 25 years of experience working in the polar regions with the British Antarctic Survey and the Scott Polar Research Institute at the University of Cambridge. Recently they’ve struck gold, as he explains to Robert Spencer. But to understand this find, we have to cast ourselves back to story which began over a hundred years ago...

Radio announcement - Men wanted for hazardous journey. Small wages, bitter cold, long months in complete darkness, constant danger, safe return doubtful, honour and recognition in case of success.

Robert - So ran the apocryphal advertisement calling for adventurers to join Earnest Shackleton on his fateful mission to cross Antarctica. Fresh out of St. John's College Cambridge, physicist Reginald W. James answered the call as his son, John recounts.

John - My father was visiting a friend in part of Cambridge that he'd never visited before. When somebody stuck his head out of a window and said, "Hey, Jimmy, do you want to go to the South Pole?"

Robert - After a brief interview with Shackleton where he was asked. Among other things, if he minded losing any toes, James and 27 other men set sail on the ship, Endurance.

John - The Endurance was actually a yacht that was built to take wealthy tourists hunting polar bears in the Arctic.

Robert - Pressed into this new scientific service, and despite the concurrent outbreak of the First World War, Endurance set sail from south Georgia for the Weddell Sea. The weather was rough and experienced 'sea-hands' had advised Shackleton to wait.

John - Shackleton said, 'No, we are going to go' in spite of the advice from the waiting captains.

Robert - It wasn't long before the ship was stuck in ice. Endurance broke free several times, but eventually the flow held it fast. The decision was taken to spend the winter in the ship and to try and complete the expedition the next year, but the elements would have different plans. Nonetheless, RW James got to work with his experiments.

John - There's a picture of him taking observations under the stern of endurance. He was doing magnetic observations, but he got very interested in the navigation side of it.

Robert - They observed eclipses of the stars by the moon, so-called occultations to maintain the time on their clocks, critical for navigation in the early 20th century. 9 long months passed.

John - But then, suddenly on Sunday afternoon, the ice opened, and it went down like a stone.

Robert - Endurance sank, 3000 meters to the bottom of the Antarctic Sea and into another world.

Adrian - The deep Antarctic is quite rich in biodiversity. You have a big range of invertebrate life, animals without backbones. For example, all kinds of sponges and corals and sea squirts. And then you have quite a high abundance of things like starfish and sea cucumbers and lots and lots of small worm-like things and molluscs in the sea bed as well.

Robert - Adrian Glover from the Natural History Museum has been studying Antarctic sea environments for years.

Adrian - All those animals are typically eating food, which has fallen from the surface layers of the ocean.

Robert - In any other waters, the sinking endurance would be part of that food chain.

Adrian - Wood gets eaten by these peculiar animals called ship worms.

Robert - Experiments run by Glover published in 2013, showed that ship worms were absent in these seas. Partly due to a lack of natural food and partly due to the strong circumpolar currents that act as a buffer between these waters and the rest of the Earth's oceans. Thus hope was high that the Endurance, if ever found by an expedition, would be in good condition. Earlier this year, such a mission set sail on the S.A. Agulhas II, a research icebreaker operated South Africa. The only clue was the rough last recorded position of the ship by his captain aided by James's timekeeping as the director for exploration, Menson Bound explains.

Menson - It wasn't like 'X marks the spot' at all.

Robert - They broke the search area up into sectors.

Menson - Eventually, just by really working in a very strict regiment manner, covering one box, then the next, then the next, we found the Endurance.

Adrian - The pictures are just remarkable. It's just sitting on the sea floor.

Menson - The ship is there. It's intact. You can see the paperwork. It's it's as good as that and doesn't get any better. It is a beautiful wreck.

John - It is quite emotional to see it again.

Robert - John's brother Viv describes a photo he has of the ship from his father's ordeal.

Viv - I'm looking at it on my wall here, right now. It just hangs there and it looks exactly the same, what we saw on the floor of the sea and what I can see on the wall here.

Menson - By definition, life after this has got to be kind of downhill.

Robert - The 28 men watching endurance sink in 1915 might have agreed. With little hope left, they set out across the frigid waters in the ship's lifeboats. They made land on Elephant Island before Shackleton and a small crew went further on to South Georgia. It's an epic tale of survival as frigid months passed for the men awaiting rescue. They were besiege by frostbite, heart attacks, mental breakdowns, and a diet almost entirely consistent of seals and penguins. Eventually at the end of August 1916, Shackleton returned on a Chilean Navy tug boat and rescued the crew. Over two years had passed since the Endurance sailed and despite the ordeal and having to shoot this sledding dogs and ships cat, not a single man perished. RW James would go on to become vice chancellor of the University of Cape Town, and two of his students would win Nobel prizes. But the ship that could so easily have been as grave rests serenely at the bottom of the Weddell Sea, almost untouched sailing into immortality.

Bacteria seen under an electron microscope

13:29 - Bacterial “skyscrapers” produce electricity

3D-printed electrodes, bacteria, light and water could be a promising combination for bioenergy…

Bacterial “skyscrapers” produce electricity
Jenny Zhang, University of Cambridge

A new housing complex for bacteria could be used to power the future! Harry Lewis spoke to Jenny Zhang from the University of Cambridge to tell us more...

Harry - Jenny, I think we're gonna have to start off with the obvious question. What on earth is this bacteria and how can it produce energy?

Jenny - Yes, let me tell you about the lovely inhabitants of this new residence: cyanobacteria, they're the most abundant life form on earth. They're actually the ancestors to some components of plant cells that carry out photosynthesis. Essentially, they are different to other bacteria because they acquire their energy from sunlight and they use this energy to combine water and air in very creative ways to produce complex molecules like sugars and biomass.

Harry - Jenny, how do you manage to get that energy that's being produced? How do you manage to take that out and create electricity?

Jenny - One really fascinating phenomena of cyanobacteria is that they leak electrons to the outside of their cells during photosynthesis. Now, this is a big loss for them since it's really hard work to get those electrons in the first place, but it's a really big gain for us because when you place these bacteria on conductive surfaces - that is, electrodes - and then shine light on them, they essentially produce free electricity for us. To answer the question what are these type of housing units that we're designing, essentially, we are trying to design electrodes that can collect as many of these waste electrons as possible. These types of structure that we're building are extremely conductive pillars with microscopic structures that can hold a lot of these cyanobacteria. You can think of them as skyscrapers or high rise homes for cyanobacteria cells, so that they can be very effective during photosynthesis and for us to harvest their electrons,

Harry - This technology - converting sunlight into electricity - sounds a lot like our solar panels. Am I being naive, or is there a big difference between the two?

Jenny - They are very similar, but there is a big difference. The biggest difference is how the electrons are being used in the two different technologies. Solar panels absorb light energy and then use that energy to move electrons around in a closed circuit. So, by itself, solar panels can only generate electricity. But, in the type of technologies that we are trying to develop, they generate electricity because of the movement of electrons, but the electrons aren't in a closed circuit; they have to be first extracted from some molecule - water, for example, which is a very sustainable and abundant resource. Then, they have to be moved and inserted into the bonds of a new molecule. In that way, it helps us to form new fuels or chemicals that we want to perhaps produce in the future in a very sustainable way. Basically, what I'm saying is that our technology is different because of the way that it uses electrons to make new molecules.

Harry - This idea of taking bacteria and generating electricity, I'm assuming it's been around for a little while, but I've noticed that your research has found that you can really generate quite a bit more. Why was it that the theoretical and the practical accumulation of energy wasn't reaching its intended or theoretical potential beforehand?

Jenny - Scientists have been looking at this for a long time and they've been working very hard to, for example, bioengineer different pathways within the bacteria so that they can give up more of their electrons. These have yielded some improvements. However, this is a very multifaceted problem, and I'm really lucky because I'm working with a fantastic team of people with very different expertise; engineers, chemists, physicists, biologists, and we're all just chipping away at the same problem. We've discovered that the one big bottleneck that was stopping us from achieving the high theoretical values that were predicted for a long time was the electrode itself. The electrodes weren't allowing enough of the sunlight to be captured by the bacteria and they weren't capturing all the electrons. By smartly rethinking the design of the electrodes, we've been able to increase the output by 10-fold. This means that we can demonstrate, and have demonstrated, that those theoretically predicted values are within reach.

Harry - What could this lead to in terms of energy creation or energy generation? Could you see these structures actually popping up in places over the globe in the future?

Jenny - Absolutely. We're dreaming big, right? We know that cyanobacteria is highly scalable. They can grow pretty much anywhere where there's water, air and sunlight, and that's why they're the most abundant life on earth. You can grow them in your pond, they can be found in glaciers, in deserts, and also in the ocean, which covers 70% of Earth's surface. I imagine that we can use these in a variety of places, but this type of technology would be great for producing electricity as well as chemicals. That's what distinguishes them from solar panels. They can also be used to make chemicals and fuels and, in doing so, in a decentralized manner, which will hopefully be affordable and sustainable at the same time because these materials are highly biodegradable and very renewable.

Harry - And putting them in remote areas would be fantastic. What a great use of space. Jenny Zang there, and her research was published in the journal Nature Materials earlier in the week, 'Bioenergy. Is it a necessary tool in our race to reach zero carbon energy?' I'll let you decide.

Someone shining a light up from a mountain at the stars and Milky Way.

19:01 - Consistent constellations across cultures

How our brains interpret visual information impacts our clustering of stars…

Consistent constellations across cultures
Charles Kemp, University of Melbourne

When you look up at the stars in the sky, what do you see? You may group certain stars into constellations, or asterisms, terms used to describe groups of stars that we like to view as related in some way. Humans have been doing this since time immemorial, placing significance on certain asterisms to tell stories and feel connected to each other and the universe. Now, a new study by Charles Kemp and a team of researchers from The University of Melbourne in Australia has been looking at the striking way in which cultures from throughout history have developed similar groupings of stars, and what this can tell us about how our brains interpret what our eyes are seeing, as James Tytko found out...

James - The night sky is a mystery which connects us all. The great cosmic questions of why and how are defining characteristics of what makes us human, and nothing brings these questions to the forefront of our minds as universally as simply staring directly up on a clear night.

Charles - Of course, people in different parts of the world see different parts of the night sky. People in the Northern hemisphere and Southern hemisphere have have different experiences, but still, it's a very important thing that's seen all around the world and it plays such an important role in culture as well.

James - Charles Kemp and a team of scientists from Melbourne have been trying to show that the shared experience of star gazing actually runs a lot deeper than we think.

Charles - We looked at a total of 27 different cultures drawn from all around the world, including cultures from Europe, Asia, North America, South America, some from Oceania and Australia as well.

James - Their work amalgamates the groupings of stars from astronomers all over the world in a bid to understand more about the way our brains interpret visual stimuli.

Charles - Maybe not surprisingly, it's rare to find an anthropologist who is expert in astronomy as well, and so is able to align what the local people are saying with the star names and accepted groupings that a Western astronomer would know. And so, because of this, there are a few really impressive anthropologists/astronomers who've had a background in both of those areas. The contributions of those people are incredibly important to the sorts of analyses across cultures that we were trying to do in our work.

James - And what were the broad conclusions you drew from this comparison?

Charles - I suppose the number one conclusion was that we think perceptual factors play a bigger role in shaping constellations across cultures than previously realised. Previous researchers would have agreed that there's a small handful of constellations that are near universal: these would include things like the Big Dipper and the Pleiadies, and so on. But, normally, when scholars talk about this, there's a list of usual suspects that includes maybe four or five groupings, but no others. But if you think about it, if there are these groupings that are near universal across cultures, and there are groupings that are one off, there's probably going to be some kind of gradient in between those two extremes, and there just hasn't been the data before to ask, for example, "So not universal by any means, but if they're appearing in half of the constellations across cultures, well, there's a striking regularity there." People all around the globe are working with essentially the same visual system and there are certain groupings that just jump out. It's well known from more than a century of research now, in visual perception, that factors like brightness, proximity and symmetry affect the patterns that people are able to see when you give them visual displays.

James - Through their work, Charles and his team are advancing the Gestalt theories of perception - Gestalt translating from German as 'pattern' or 'configuration'. Appearing in the early 20th century, they were the people who first developed the idea that characteristics such as brightness, proximity and distance between objects were responsible for how we view individual elements and grouped them together into a hole.

Charles - In fact, some of them informally mentioned constellations, star groupings, as examples of exactly the sort of grouping that they were interested in. As far as I know, nobody ever followed that up experimentally. There are experiments where, in the lab, people are presented with random dot patterns and what's interesting is to see how those patterns get organised into groups, but no one has ever really tried to use stimuli that look a bit more like actual stars and, for example, vary in brightness.

James - I wonder if we could zoom in on some striking similarities, maybe, between two very disparate sets of astronomers. Disparate by way of age or by distance. Examples that really leap out as surprising that people have connected together.

Charles - Well, maybe just one example that comes to mind: in the Western tradition, if you look at the accepted official 88 constellations, there's Corona Astralis and Corona Borealis, and both of them are groupings of stars that fall along the arch of a circle - kind of these smooth curves. They're both known as crowns or wreaths; I think maybe in the Greek tradition wreaths would be just as accurate a description. One of the cultures in our dataset, the people of the Marshall Islands, identify the same two constellations pretty much. Not only that, they refer to them as wreaths as well. So, in their culture, I think the relevant wreaths are wreaths made out of flowers. To me, that's a striking convergence. People have not only identified the same groupings across these two cultures, but they've interpreted them in the same way.

Typewriter with paper saying 'Goals'

26:17 - Why changing behaviours feels hard

From new years resolutions to Monday mornings, how we are designed can make change difficult…

Why changing behaviours feels hard
Katy Milkman, Wharton School of Business

Harry Lewis and Julia Ravey were trying to change their behaviours by following a New Years Resolution, but they haven't been doing too well so far. In order to help them restart their attempts, Katy Milkman, a behavioural scientist from the Wharton School of the University of Pennsylvania, came in to explain why it's difficult to make a change, even when we know we want to do so, and gave a few methods to help them along the way...

Katy - Change is not just about making up your mind because there are all these internal barriers, not to mention the external ones. Do you have the financial resources? Do you have the health resources? All the things you might need? But even if you've got that all in line, our mind is working against us. The way we're designed, we tend to be present biased for instance. Which means that instead of focusing on long term rewards, we overvalue instant gratification, that makes change hard. We tend to reach for the path of least resistance, whatever is easiest, that's what we want to do. We often lack confidence in our ability to do something new and challenging and if we don't have confidence to make a change, then it's really hard. We have all these different barriers. That's just a subset of them that are working against us, that are part of our design or our operating system.

Julia - And so are there things we can do to make change a bit easier for us?

Katy - Yes, thank goodness. Science has lots of great evidence to offer on what we can do to make changes. I do think it's very important to say that the best tools for creating change in your life are going to depend on what the barriers are that are standing in your way. One of the most common barriers is we think that the best thing to do is find the most efficient path, but a small fraction of people make a different calculation. They actually think, 'what's the most fun way I can pursue change?' That sounds like a worse way to get there, it's going to take longer, but that's a better path. The reason is if we pursue change in ways that we find fun, we persist. One way that I have shown we can make change more fun and persist longer is through doing something I call 'temptation bundling', which is linking something that feels like a chore with a source of pleasure and temptation. For example, only binge watching your favourite TV show while you're on the treadmill. If you can find a source of pleasure that you can link with what would otherwise be a chore, it transforms the chore into something you might actually look forward to.

Julia - You did a big study about going to the gym and testing lots of different interventions - were there any interventions that stood out as being a class above the rest?

Katy - Yes. Lots of scientists in a tournament-like style submitted their best ideas for how to motivate people to go to the gym. Then we tested all these different month-long digital programs to motivate exercise against one another. We did it with about 63,000 Americans who were members of a popular gym chain. It was helpful to get people to make a plan; what are the dates and times when they were going to go to the gym? Then we'd send them text reminders to show up for the gym at that time, and we gave them points that were basically worthless. They were worth about 20 cents per gym visit. It wasn't a huge amount, but it gamified it and gave them a little micro-incentive. Then we layered on some additional ingredients and the most powerful of those additional ingredients, believe it or not, just focused on getting people not to miss two workouts in a row. Say you normally schedule yourself to go to the gym on Thursday and Friday one week, but we designed one version of the program where you'd get a tiny, extra sweetener to come back on Friday if you'd missed Thursday. It wasn't enough that you'd ever skip strategically, it was 10 cents, but it was enough to give you the sense that it's not a good idea to miss more than one workout in a row. That turned out to increase gym attendances by 30%. We found lots of other interesting things that increased exercise too, including giving people free audiobooks that they could link with their workouts. That was something that was successful. We also found that telling people, lots of other people are exercising - that gives you the sense that this is a social phenomenon you don't want to miss out on - and that increased exercise by about 25%. The good news is behavioural science is full of insights that can be used to improve our outcomes when it comes to behaviour change.

Julia - After hearing about the success of the interventions in Katy's study, I decided to set the Naked Scientists team, a little challenge: Over the next week, I want you all to take a walk from Cambridge to Liverpool (as a group). So Cambridge to Liverpool is 192 miles, and I did a little very accurate step calculator online, which comes together as 460,800 steps.

Harry - How many?

Julia - 460,800 steps. But based on the data I've had in so far from everyone, we're all walking less than what we need to walk per day.

Harry - I do about 300 steps a day.

Anoushka - Pick up the pace man.

Harry - I'm not joking.

Julia - Well for this you need to do 8,228 steps per day, for 7 days.

Harry - I've had to take my smart watch off because my mom keeps calling to ask how many steps I've done. I don't want to be berated anymore.

Julia - Well, it's a group effort, so you could do less steps and someone else can do more.

Harry - I like that.

Julia - You know what I mean? We can try and get to Liverpool but we might end up somewhere else on the M6.

Robert - What do we do when we get to Liverpool?

Julia - We're going have a party at my house.

Anoushka - We're going to the bingo place.

Julia - And to spice this challenge up, I decided to give each member of the team a different intervention to boost their step count. These interventions included.

James - If you hit your target each day, you'll get a treat of your choice at the end of the week,

Harry - James has been looking at a Tiffany ring recently.

Julia - A daily reminder.

Evelyna - Every day, receive a text message reminder to prompt walking.

Harry - Yours is so much worse than James'.

Julia - A reward during doing the step count.

Otis - Pick an audio book of choice and only listen to it while I'm walking.

Julia - A pre-commitment.

Robert - I have to sign a contract now to commit to walking the required number of steps. Somehow. Julia, I don't think that these are randomly assigned.

Julia - Planning ahead of time.

Anoushka - Add to schedule a reminder for when I should walk each day.

Harry - Lucky.

Anoushka - I am lucky. I like schedules.

Julia - A daily reflection exercise. 'Each day, look at your walking counter and think about what you can do tomorrow to improve.' And finally...

Harry - No intervention.

Julia - Harry seemed happy with that one.

Harry - The information received today is all the information you will get.

Julia - This time in a week's time from now, we'll meet again. We'll see if we've hit that target of getting to Liverpool as a group. Catch you in a week.

Model of brain with purple hue

34:22 - How the brain governs behaviours

When we act, there are several neural systems at play which mediate our responses…

How the brain governs behaviours
Trevor Robbins & Leor Zmigrod, University of Cambridge, and Ingo Willuhn, Netherlands Institute for Neuroscience

Fun activities and doing something social can help motivate change. But why do we need interventions or tricks to push ourselves to do the things we actually want to do in the first place? Trevor Robbins, from University of Cambridge, and Ingo Willuhn, from the Netherlands Institute for Neuroscience, gave Harry Lewis an insight while Julia Ravey had her habit tendancies assessed by Leor Zmigrod from the University of Cambridge…

Trevor - So one notion is that there are 3 basic systems controlling our behavioural output. One of these is a very ancient system, a Pavlovian system.

Harry - This system is key for making associations. If every time a bell rang, you got a piece of chocolate, over time you'd come to expect that little sweet treat upon hearing the sound.

Trevor - From the Pavlovian system, you can assess causal things in the world, but you can't do very much about them. To give you control, you need what we call 'instrumental behaviour' or 'goal-directed behaviour.'

Harry - If you walk into a dark room, you might flip the light switch on so you can see what is there. Now that is goal-directed. The aim is to see and the action of turning light on makes it possible.

Trevor - Then the third system here, which is probably very ancient, is a so-called 'habit system'.

Harry - This system links situations and responses so behaviours can be performed in an almost-automatic way, without much concern for the outcome. Say you walked into a room and one time you switched the light on to find the bulb was broken, but the next time you walked in, even without replacing it, you press a switch again anyway. That would show that the behaviour is habitual because you aren't getting the outcome - the light - you desire, but perform the action anyway.

Trevor - The balance in our everyday behaviour is among these 3 controlled systems and they work rather dynamically between themselves.

Harry - When we are trying to introduce a new behaviour, like going to the gym or eating more fruit or studying for a test, these are goal-directed. We're performing an action with an outcome in mind. But this system isn't always the best to use as Ingo Willuhn from the Netherlands Institute for Neuroscience explains...

Ingo - Goal-directed behaviour requires more computational power, more brain power. You need more brain power to execute them because they're more complicated. You are also more flexible and you're more precise and you know the big picture of everything that your behaviour is taking place in, but it's more costly in a way. The habitual behaviour is the low-cost eco-mode of your brain. It's not very costly for your brain to compute just a reaction to some stimulus that pops into your visual field.

Harry - Making behaviours habitual can be beneficial. Over time, with repetition or under certain emotional conditions like feelings of pleasure or avoidance, once-new behaviours can transition into habitual responses, saving the brain costly energy. Ingo studies this transition in animals...

Ingo - What we do with our rats is we teach them that they get food for a certain action, and then at some point you take the food away and see if the rat stops doing this behaviour. That would be a goal-directed decision. 'There's no food anymore. Why would I keep doing this?' However if it's habitual, then you know that the animal will keep pressing that lever, even though there's no outcome anymore. It's extinction-resistant in a sense.

Harry - Exactly what happens in the brain when a behaviour transitions from goal-directed to habitual is still under investigation. These behavioural systems are governed by certain brain circuits, like highways whose traffic levels are influenced by different chemicals, including a common one you'll know called dopamine.

Ingo - The idea was that this control of the behaviour would switch from one highway to the next and to the next.

Harry - But Ingo's latest study found something different about dopamine.

Ingo - And in our study, we actually found that this switching doesn't really happen. It seems like dopamine is present and important in all these highways throughout the entire development of habits.

Harry - While scientists continue to unpick what happens in the brain when a behaviour moves from being goal-directed to habitual, we can learn more about our own preferences for routine responses using questionnaires. Julia volunteered to have her habit tendencies assessed. Good luck, Jules.

Julia - I've just logged on to do a questionnaire about personality, behavioural preferences, and problem solving. We'll see how I get on. In the questionnaire I am being asked to rank certain traits that I think about myself. 'I tend to change my plans last minute.' Disagree. 'I avoid situations where unexpected things happen.' Agree. 'Life is boring if you never take risks and always play it safe.' Somewhat disagree, I am boring. 'I like to plan ahead in detail rather than leading things to chance.' Strongly agree. 'I like being able to organise everything in advance.' Strongly agree. 'I feel anxious when things change frequently.' Agree. It's done. That was really quick. Now I will await my results. I wonder what that analysis will show.

Leor - Hi Julia.

Julia - I spoke to Leor Zmigrod from the University of Cambridge who designed this questionnaire.

Leor - I look at what makes some individuals more flexible and adaptable and other people more habitual.

Julia - I've done the questionnaire. Do you have my results?

Leor - I do. Julia, you are one of the most creatures of habits that I've ever seen. It's not a bad thing - we're all different. When I look at your habit profile, we see that your highest score is on what is called 'preference for regularity'. You really like having routines and you feel that they're comforting. Is that true?

Julia - Yes, I find real comfort in routine and if I don't have routine, I feel all over the place.

Leor - When it comes to aversion to novelty, that was your least habitual domain. You actually did look forward to new experiences. This can help us see what kinds of contexts you will like more, or you will like less, where you will thrive, what kind of disorders you might be at higher risk for, or more resilient to. But again, all these individual differences always interact with the environment.

Julia - Wow. So I'm obviously a creature of habit.

Harry - You are indeed. You're an absolute routine-fiend Ravey with that chocolate fixation of yours.


41:06 - Understanding habits in OCD & addiction

Extreme habitual behaviours can be observed in these debilitating conditions…

Understanding habits in OCD & addiction
Trevor Robbins and Máiréad Healy, University of Cambridge

Trevor Robbins and Máiréad Healy explain to Julia Ravey how disorders like OCD and addiction could be down to problems with goal-directed and habit-based systems...

Julia - Most of our day can be governed by habits. We wake up at a certain time, brush our teeth, take a shower, make tea, drive to work, check emails, scroll on social media, eat lunch, do tasks, drive home, cook dinner, watch telly, scroll some more, and then go to bed. While certain habits can be good for us, there are other behaviours which may not be as beneficial. We may be in a habit of eating too much sugar, or being physically inactive, or spending too much time online. And in the most extreme instances, habitual behaviours can be disruptive. Behaviours carried out can do real damage to our health, relationships, and life as a whole. There are certain conditions where the goal-directed and habit systems are thought to be compromised, as Trevor Robbins explains...

Trevor - People talk a lot about addiction habits, don't they: "I've got a drug habit, I've got a cannabis habit, I've got a smoking habit." In certain disorders, for example, substance abuse and addiction, obsessive compulsive disorder, compulsive eating, compulsive gambling, there's going to be some tendencies to these more automatic behaviours.

Julia - Trevor is currently trying to understand the underlying biology of obsessive compulsive disorder, or OCD.

Trevor - OCD is a very serious and disabling disorder. I'm talking about people who perform rituals for 12 or 13 hours a day and their lives are shattered. We think obsessive compulsive disorder may be a derangement of control over habits.

Julia - I wanted to learn more about how Trevor and his group are trying to understand OCD, so I paid a visit to his lab. I'm here to speak to Máiréad Healy, who's with Trevor Robbins' group, to hear how they are studying this debilitating condition.

Máiréad - Our lab is focused on looking at the brain basis of compulsive behavior, or how habits are formed in people with OCD, so we can learn more about the brain basis of compulsions.

Julia - And how do you go about studying OCD?

Máiréad - Sometimes we are using neuro-imaging techniques to give insight into what's happening at the brain level. We also use behavioural tests that will give us insight into what cognitive mechanisms are underpinning these behaviours. We combine them together so we can get an overall picture of both.

Julia - Máiréad let me demo one of these behavioural tests. The screen displayed several boxes with different patterns in them. I had to select one and got told if it was correct or incorrect. And then I had to keep selecting the correct image as the display changed. Which pattern was correct would change throughout the game without me knowing, and this would assess my ability to think flexibly, updating the target pattern as I went through.As I complete my task, here is Trevor to explain how, in conditions like addiction, the habit system may take over...

Trevor - One idea would be, for example, when a drug like cocaine or amphetamine has its initial hit. That hits this Pavlovian system, which gives a strong, positive approach tendency, but the issue is what happens chronically when you get this over and over again. Because habits are probably promoted by extended training, a rat responding for cocaine is just like a rat responding for food. And eventually, maybe that behaviour becomes habitual. But then the other thing you've got to realise is that there may be a predisposition to have a relatively weak goal-directed system to begin with, and that's been demonstrated in humans and in animals. So, you've got a double whammy - you've got this gradually strengthening habit plus loss of control, which we argue equates to compulsive drug seeking.

Julia - What happens in the brain of someone with OCD is currently less well understood than addiction, but there are thought to be some similarities in the loss of control of the goal-directed system, based partially in the area of the brain that sits right behind the eyes called the frontal lobe.

Trevor - It turns out that the frontal lobes are relatively disconnected in OCD and, of course, in similar addiction. That disconnectedness correlates with the degree of compulsive behaviours. That's pretty amazing that the same area is disconnected, and it relates to compulsion in both cases, although the actual nature of the compulsions are different. But we would argue that the habit system probably must gain prominence as a result of that overall down regulation of the directed system.

Máiréad - So, that task is part of a battery of tasks that we administer to participants and in OCD sufferers, we hypothesise that they will find this task difficult to do the role reversal because they'll be stuck in a more habitual behaviour.

Julia - After someone has done this type of task, then what would you go on to do?

Máiréad - We have another task that's one of the key tasks that we use because we get the participant to perform this in the scanner, so that we can relate their behaviour to what brain circuitries or brain areas are supporting this behaviour

Julia - Now, I was going to get my brain scanned, but sadly, because I have a brace on my teeth, I can't go in the scanner. But what Máiréad will be looking out for here is how the brain of people with OCD, and individuals without OCD, differ in their activity when playing a game like the one I just took part in. The group is also looking at differences in brain chemicals in these systems too, to try to paint a clearer picture of what is going on in OCD and other habitual disorders.

Mairead - We really hope that we can make an impact into the lives of people who have OCD and better our understanding of habits. We all have to get the balance right between our goal-directed systems and our habit-based systems, so this work is really important for the clinical applications, but also just to have a better understanding of how we form habits and how we can improve our daily lives by adapting to our environment in a way that will help us achieve our goals.

Goal setting diary with coffee

48:41 - A method for building new behaviours

If trying to make a change in your life, one protocol suggests going small is the way forward…

A method for building new behaviours
BJ Fogg, Stanford University

BJ Fogg, the author of “Tiny Habits” from Stanford University, has offered a helping hand to Julia Ravey & Harry Lewis in finally kick-starting New Years Resolutions resolutions using his approach for change…

BJ - Make it super tiny - set the bar really low. Let's say you want to read more books. Many people say, "Oh, I'm going to read a chapter a day." Well, that takes a lot of time. So, instead, in the tiny habits way, you scale back the chapter to a paragraph, or even one sentence, and then you find where that fits naturally in your life: "Okay, I'll read one paragraph of my book after I sit down with my morning tea." And if you want to read more than one paragraph, you can, but you set the bar so low that every day you can do it really reliably. And you say, "good for me. I did my habit," and you move on with your day.

Julia - And you mentioned a few processes there. You were saying, "Sit down with my tea, then I read, and then I say well done me."

BJ - Yes, exactly. And those three parts are A, B, C. What is going to remind me to do the new habit? We call that an anchor. The anchor is something you already do, like sitting down for tea or turning off the telly. Then, the B is the new behaviour you want to make a habit of, so reading a paragraph from a book. Then, as you do the habit, or immediately after, you say, "Good for me." You reinforce yourself. You cause yourself to feel successful. So, that's ABC: anchor, behaviour, celebration.

Julia - So, Harry and I, we had new year's resolutions this year. It's March. We haven't been successful with them right now. I thought I'd put them to you to try and tiny habit-ify them. So, one of them was to build strength: to get stronger and feel more healthy. What would you do for that type of behaviour?

BJ - Pick the upper body exercise that you want the most. So, what do you think Harry's going to want the most?

Julia - Let's say he'll do a push up. I'll make him do them.

BJ - Okay. You don't do 10 or 20, you do 1 or 2. You make it so tiny that it's just super easy to do. Then, it's finding where does this fit naturally in Harry's life? What does it come after? It's hard for me to know Harry's routine. Where do you think it would fit for Harry?

Julia - He loves a cup of tea. He's always in the kitchen here, boiling the kettle.

BJ - Okay, good. The tiny habit recipe becomes, "After I start the kettle, I will do two pushups." And then as Harry stands up, "Good for me," or, "Way to go," or just say "I did it." Harry, dive in and practice that, and if for some reason that doesn't fit, after you start the tea, then look for another place where it might fit.

Julia - My one was, I have a terrible sweet tooth, but only in the evening. After I've had my dinner, I feel like I have to have a chocolate bar or a cake. I really want to replace it with eating something a bit healthier, like fruit. How can I tiny habit-ify that?

BJ - Well, first of all, you are not alone, for sure. You know that, right? This is really common. The first thing is to make a list of all the snacks that you might eat after dinner that you consider healthy. On your side, what might be on your list of healthy snacks?

Julia - I love strawberries with Greek yogurt.

BJ - So, the next step for that is to buy the yogurt and prep the strawberries. Wash the strawberries, get them ready. If you like them sliced up, get them pre-sliced. Then you would design it into your routine like we did with the pushups. What would be the specific moment after dinner that you would do that?

Julia - It would be taking my plate to the sink, because that's when I go to the cupboard.

BJ - So then, and you would actually write this down, you'd write it down on a note card, "After I put my plate by the sink, I will prepare my snack for the evening." And then, as you open the fridge and you see those two things, tell yourself, "Good for me. I'm on my game plan." Let yourself feel successful that you're following through with this game plan you designed for yourself. Now, in addition to that, remove the chocolate from your home. I know, I know, but this is part of it. You don't have to do this, but if you want to increase your chances, try it for three days and see how it goes.

Julia - I'm going to give that a go. I'm sure it will help me.

BJ - It will. And if it works, you keep going and if it doesn't, that's okay. You don't beat yourself up. It's sort of like decorating a room where you want to put a new painting on the wall, and if it doesn't fit there, you don't beat yourself up. You just redesign. In the tiny habits method, a big part of it is to iterate, to try things out. And if it doesn't work, you don't blame yourself because it's a design process, and you just accept that as a positive. You've learnt something, and you redesign it and try again. You change best by feeling good, not by feeling bad.

Julia - It's been a week since I set the team the walking challenge. So, I'm going to see how we've done and which intervention fared best. The results are in, and I've had everyone's results except for Harry. Where are your steps?

Harry - I didn't record my steps.

Julia - Why?

Harry - There wasn't much motivation. I think I have walked a lot more, but I didn't switch on the health tracker on my iPhone.

Julia - You need the trundle wheel.

Harry - What the heck's a trundle wheel?

Julia - I've given Harry a rough average for his steps. The counts were all added together and this is what the results showed. What I can say is that, for all of us, no matter what the intervention was, everyone has improved in their step count in the past week. Maybe that's because we were all under a challenge, but the best intervention based on the percentage increase was Otis'. Otis improved by 55%. Remind us what your intervention was, Otis.

Otis - During the walking process, I would be listening to an audio book.

Julia - So, this week, we've walked, as a collective, 425,467 steps.

Anoushka  - Not far enough.

Julia - That's 177.3 miles. We almost got there. The target was 460,800 (steps). We pretty much hit Warrington. From my house, to Warrington, you can drive there in about 15 minutes. So, I'd say we're not far off and you know what, because we've done so well, Shelly will come and pick us up in the car.

Harry - Shelly's your mom, Julia?

Julia - Yeah, Shelly's my mum.

Harry - Is that a round of applause?

Julia - That is a round of applause. Well done everyone.

Scratching an itch

56:42 - QotW: How can an itch move around the body?

We find the answer to this head-shoulder-knee-toes-scratcher.

QotW: How can an itch move around the body?

Otis Kingsman interviewed Dr Yvonne Couch from the Radcliffe Department of Medicine to find the answer...

Yvonne -  Humans have about 22 feet of skin, and for each square inch of it there are about 1000 nerve endings. When these free nerve endings become active, they send signals through your spinal cord to your brain, giving you the feeling of an itch.

Otis -  Scratching an itch it an attempt to remove what is causing these nevres to become active from the surface of the skin. But what kinds of processes can activate these nerve endings?

Yvonne -  If you have any kind of neurological disease, or you’re being treated with a drug like morphine, you can end up with itches that start in your elbow and end up in your feet as caused by multiple different nerve endings becoming active.

Otis -  Internal stimulants can mean itches occur in multiple places at once. But what about the more common itches?

Yvonne -  When we get something like a mosquito bite, or some degree of local tissue damage, Histamine is released in the skin. It’s an inflammatory molecule, designed to open up your blood vessels and bring more blood to the injured site to fight off infection. But in the process, the blood vessels brush past and stimulate the free nerve endings, leading you to itch it.

Otis -  In the process of combating our injury, the blood vessels inadvertently make our brain think we’re in more distress. But why does scratching become addictive?

Yvonne -  Itch signals have been shown to stimulate bits of your brain associated with reward so you end up almost addicted to scratching because it produces more itch, which produces more scratching and more itching!

Otis -  This pleasure sense from the brain is what keeps us scratching. And the more we scratch, the more damage we cause to the skin.

Yvonne -  The signal gets to your brain and a bunch of central processing tells you to scratch the itch. Scratching around the area of the itch though, causes local irritation in the surrounding skin, which releases more histamine and activates more of those free nerve endings, sending you into what the scientists imaginatively call ‘the itch-scratch cycle’.

Otis -  When you scratch an itch, you are telling the brain to release more Histamine to make the surrounding blood vessels expand and stimulate the nearby nerve endings. Because your brain likes it when these endings are scratched, it leads to the itchy area expanding and expanding until your whole body feels itchy.

Yvonne -  When your mum told you to not scratch because you’ll only make it worse, she was right!


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