Lost

It's hard to imagine how terrifying being utterly lost is until you experience it. For me it was in the Amazonian jungle of Peru during a gap between PhD and post-doc. I'd taken a short stroll from my camp along what looked like a clear trail. After short time I turned round to return and was astonished. My path ahead soon petered out, dispersing into the jungle. I'd taken a wrong turn.

I was not too worried at first, but when a second trail also evaporated into the undergrowth fear started to grip me. Sheer terror arrived when, after I had walked a while, I realised I had gone in a circle. I was back at a distinctive log and hopelessly lost. No idea of the correct path or the direction home.

My guide had said: 'if you are ever lost in the jungle at night, get your back against a tree and stay still – at least one part of your body won't be utterly bitten to death!' Luckily for me it didn't come to that, I was found by a dog who looked suspiciously like Lassie. I also found my interest in navigation had risen. Why was I unable to realise I'd walked in circle? How do people in traditional communities manage to navigate in such confusing environments for days on end and indeed how do other animals do it too?

The fear of being lost is something we share with vast numbers of animals on our planet. Being lost puts us in harm's way – without help I would not have survived for long in the jungle.

Modern humans have developed a multitude of tools to avoid being lost: maps, signs, the compass, and global positioning system (GPS). But without such tools some humans are able to navigate challenging terrain, from taxi drivers in vast cities to the desert travellers. How we and other animals are able to orient and recall how to travel to far off remembered places is remarkable.

How does our brain keep us from being lost? In a recent co-authored book, Human Spatial Navigation, I helped set out to answer this question. One exciting path on the quest involves eavesdropping on the neurons in the hippocampus by recording their activity during navigation. In 1971 John O'Keefe made an amazing discovery – as rats scurried around in a box searching for food, different hippocampal neurons would be active in different parts of the box. The conclusion drawn was that these cells – known as place cells – provide something akin to 'you are here' signal in an organised mental map of space.

O'Keefe would go on to co-win the Nobel prize for physiology and medicine in 2014 for this discovery and laying the foundations for how the brain creates this map of space – what keeps us from being lost. In the past decades so many amazing insights into how we build mental maps of space have come from studying hippocampal place cells and other spatial cells in regions of the brain connected to the hippocampus.

Beyond individual cells whole brain wide it has been possible to observe how the brain tracks distance and direction information during navigation using functional magnetic resonance imaging (fMRI) and virtual reality. Recording from depth electrodes in the hippocampus of humans awaiting surgery for epilepsy has given us even more detailed insights, most recently with humans walking around environments while brain activity is recorded. Another key discovery has been the observation that London taxi drivers have a larger posterior hippocampus. Notably it increases in size with amount of years of working as a taxi driver in London, but not for bus drivers who drive the same routes daily.

Recent research with the mobile application – Sea Hero Quest – has allowed my team to explore how 3.9 million people across our planet navigate spaces, revealing that Nordic nations appear to produce the best navigators and that gender differences can be traced in part to societal gender inequalities between nations.

Despite all these discoveries there remain many unknowns. Why do some people get lost more than others? How do some animals manage to navigate such huge distances? How do people in traditional communities avoid being lost?

In a set of recent books for general readers on being lost and navigation, authors have explored answers to these questions. What is wonderful about these books is the approach to enquire and interview experts to get to the bottom of some of the problems, but then to re-contextualise the science from a personal perspective. They come away with some interesting answers and discuss ideas with some remarkable people.

- Hugo Spiers is Professor of Cognitive Neuroscience at University College London.

Key sources

Ekstrom, A.D., Spiers, H.J., Bohbot, V.D. & Rosenbaum, R.S. (2018). Human Spatial Navigation. Princeton Uni Press. 

Coutrot, A., Silva, R., Manley, E., de Cothi, W., Sami, S., Bohbot, V., Wiener, J.M., Hölscher, C., Dalton, R.C., Hornberger, M. & Spiers, H.J. (2018). Global determinants of navigation ability. Current Biology, 28(17).

Maguire, E.A., Woollett, K. & Spiers, H.J. (2006). London taxi drivers and bus drivers: a structural MRI and neuropsychological analysis. Hippocampus, 16(12), 1091-1101.

'That mysterious border between what science can and cannot explain'

Maura O'Connor

What got you interested in wayfinding / being lost?
Years ago, I tried to use GPS to get to an extremely rural place in New Mexico. The device led me to the edge of a very steep cliff. It was such an absurd experience that it got me thinking about navigation more generally and asking questions about how humans wayfind. Millions of people have adopted GPS today and it creates this sense of incredible mastery and control over our surroundings. But the more we rely on it, the less information and knowledge we seem to absorb and retain about the landscapes around us. I started talking to anthropologists who have documented the astonishing diversity of human navigation practices around the world, as well as the neuroscientists trying to understand the neural basis of navigation.

As a journalist, that mysterious border between what science can and cannot explain is very interesting to me. There are still so many different theories about human and even animal navigation. How do humpback whales find their way across an entire ocean? We still don't really know. We don't even know for sure how a butterfly navigates.

What surprised you when you researched the topic?
There's still this idea out there that so-called hunter-gatherers are primitive wayfinders that navigate much like our prehistoric ancestors did, or even use some kind of 'sixth sense'. This is totally wrong. People tend to generalise navigation from a Western perspective which focuses a lot on a very specific problem: navigating unknown places. So, it's a struggle to understand how people from other cultures find their way in 'wilderness' without material technologies such as maps or instruments.

The truth is that there is an amazing range of navigational systems that rely on highly sophisticated combinations of observation, memory and inter-generational knowledge. Mapping and map-reading is just one type of navigation strategy among many. Individuals learn unique cultural practices and skills to orient and know where they are with great accuracy. In some places, indoctrination into cultural navigation practices starts in childhood and absolute mastery can take many decades.

Can you give us an example?
I met Solomon Awa, the Inuit community leader and legendary hunter in Nunavut. Awa's personal story of being born in a sod house and growing up on the land with his father and mother while all of his brothers and sisters were forced to go to residential schools is very moving, and he is someone who has thought so deeply and extensively about navigation and how it works. 'Do you have 30 years?', he joked when I asked if he would talk with me about Inuit wayfinding. He can talk about the logic of geography, wind, stars, snow. His opinion is that Inuit navigators can commit a staggering amount of visual information to memory. Rocks and snow all look the same to outsiders but he can 'read' the landscape and travel hundreds of miles using very innocuous landmarks. I saw, thanks to him, how practicing traditional navigation in Nunavut (and other places) is a potent form of cultural self-determination and decolonisation, connecting people to the land, language and stories. And the kind of empirical observation he practices are also how people are tracking the impact of climate change on their homelands.

Who else did you meet along the way?
I loved talking to the late neuroscientist Howard Eichenbaum about his research and theories of the hippocampus. He saw navigation as a story or memory problem. As such, to him the hippocampus was not about spatial memory, it was more about something he called 'memory space'. And he talked about the hippocampus as this grand organiser of the brain that mapped time and space but also other dimensions of our experience, like social relationships and even sound. It was a joy to listen to a neuroscientist philosophise about the significance of the hippocampus in human life and marvel at how the brain works, even after decades at the top of his field.

Were there any questions you were surprised haven't been answered?
I'm really looking forward to the future of research on hippocampal development in children. We know that the hippocampus develops in infancy and childhood, a time in which circuits are maturing, and new cells are firing and encoding space to create cognitive maps. But we don't know for sure how much of kids' experiences – exploring environments, navigating space, self-locomotion – influences how the hippocampus develops. Likewise, how much might limiting children's independent exploration of space – which is happening across many cultures as people become risk averse – affect the hippocampus?

I love the ideas of the psychologist Edith Cobb who described children as possessing this 'genius loci', the ability to explore the world in highly evocative ways. She believed they have this capacity for highly exceptional perception of time and space and moments of transcendence. I'm excited to see the ways in which new research in neuroscience and psychology might illuminate more about children's unique and mysterious relationship to wayfinding.

What concept was hard to get your head around?
The environmental psychologist James Gibson had some incredible ideas about wayfinding: he argued that humans could directly perceive the world through ecological information rather than assemble our sensory inputs into mental representations. Likewise, he argued that navigation isn't based on a cognitive map in the brain but on our immediate experience of the environment, which he described as a sequence of transitions… the stretches of connected sequences over time, that connect vistas. Gibson said that wayfinding 'is not so much having a bird's eye view of the terrain as it is being everywhere at once'. I'll probably never stop thinking about that quote and trying to understand it!

Has writing the book changed you in other ways?
I have a profound appreciation for my own ethnocentrism now. It was a shock, for example, to me that being lost is not a common experience at all among the traditional wayfinders I spoke to. In some places, it's almost unthinkable that people can get lost. The anthropologist Thomas Widlok, who spent many decades with the San people of the Kalahari, helped me to understand why this is. Being lost is a very specific historical situation that stems from trying to chart unknown territories. And exploring unknown places is very different from the type of navigation indigenous people practice in Australia, the Kalahari or the Arctic, for instance. I remember talking to a Jawoyn elder in northern Australia, Margaret Katherine, who laughed at me when I asked what she did when she got lost. If you grow up immersed in your people's Dreaming stories and know how to use everything from trees and termite hills to stars and landmarks to orient over hundreds of kilometers, getting lost is just not something that happens very often. You are always at home no matter how far you travel.

'The connection between physical navigation and mental health is fascinating'

Michael Bond

What got you interested in wayfinding / being lost? 
Firstly it's a very exciting time in spatial neuroscience with all the recent findings about how the brain allows us to navigate and the role of spatial cognition in memory, so it felt like a great subject to explore. Secondly, in my family there are both excellent and terrible navigators, and I've always wondered why people can differ so much at this skill.

What surprised you when you researched the topic? 
It surprised me how much we don't know about how the brain makes sense of space. For example, it isn't clear where spatial memories are stored, nor how the place cells and grid cells – two crucial elements in the cognitive map – cooperate. The mechanisms behind place, grid, head direction, boundary vector and other spatial cells in the hippocampus and entorhinal cortex are quite challenging to get your head round when you're starting from scratch, though of course it forces you to ask all the dumb questions so you can get it right for your readers.

Was there a particular area that you found thought provoking?
The connection between physical navigation and mental health is fascinating. When I told friends that I was writing a book about why people get lost, many of them would ask, 'physically or mentally?' The two are similar in many ways – we use the same language to describe them, and they affect some of the same parts of the brain. The emotional experience of being lost in the wilderness is comparable to what it feels like in depression: the fear, the distorted thinking, the alienation from your surroundings, the sense you might die.

Where there any questions you were surprised haven't been answered?
What is a cognitive map? In my naivety at the start of my research I assumed they'd nailed this one. The fact that they haven't makes the subject more fascinating.

Who did you most enjoy talking to when researching your book?
So many to choose from. I enjoyed getting the very different perspectives from the two groups who in a sense are at either end of the discipline: the neuroscientists looking for answers in the brain, and the search and rescue experts observing how people behave in the real world. It would be interesting to get these two groups together to try to tackle some of the enduring mysteries about human navigation. For example, why people who get lost in the wild tend to gravitate towards boundaries – paths, tracks, the edges of forests, a line of telegraph poles. That's something neuroscience might help with.

Has writing the book changed the way you behave?
It's made it clear to me how deeply we're affected by our surroundings and how they touch us emotionally. Also how important it is to pay attention if you want to remember where you're going. I do try to pay attention more – a work in progress!

'On a transatlantic voyage in a small yacht when I was 19, I was introduced to the wonders of celestial navigation'

David Barrie

What got you interested in wayfinding / being lost?
As a teenager who did a lot of sailing I was fascinated by the challenges of marine navigation – this was of course long before the advent of GPS. I was especially interested in how you could tell where you were when out of sight of land. This was a major problem until the mid-18th century, when celestial navigation came of age with the discovery of two different solutions to the longitude problem. On a transatlantic voyage in a small yacht when I was 19, I was introduced to the wonders of celestial navigation. I wrote about this life-changing experience in my book, Sextant.

I'm still entranced by the fact that you can fix your position on the surface of this planet by reference to the light of the sun and stars. That is just sublime! It's worth recalling that until the 1960s celestial navigation was the key to making accurate maps of the world. We owe a huge amount to the generations of scientists, mathematicians and instrument-makers who made all this possible, though we tend to forget their achievements now that we have GPS. 

What surprised you when you researched the topic?
When I was researching Sextant I discovered that many other animals – from ants and bees to birds and butterflies – were also celestial navigators. This led me to write Incredible Journeys – a book that explores the science of animal navigation. My research took me round the world and introduced me to a lot of the leading scientists working in this field. And of course there were many surprises. For example, I was amazed to learn that nocturnal dung beetles maintain a straight course as they roll their balls of dung by reference to the light of the moon or, failing that, the orientation of the Milky Way.

I was also deeply impressed by the work of the neuroscientists who are unravelling the brain circuitry that supports navigation. I was astonished to discover just how much the tiny brains of insects can do: they are a perfect illustration of the power of evolution working over hundreds of millions of years.

What about birds?
One of the most intriguing questions is how homing pigeons can find their way back to their lofts, even when they are taken (under anaesthetic!) to a place they've never before visited – which may be as much as 300 km away. There's a good deal of evidence that their sense of smell plays an important part in this remarkable behaviour. Some researchers think they must be making use of 'olfactory maps' of some kind, but this is still controversial. Another intriguing possibility is that pigeons may be making use of infrasound signals that carry over great distances to help them home in on their lofts. Of course it's possible that both theories are correct – or neither!

Don't many animals use the Earth's magnetic field?
Yes, many animals – including bacteria, newts, marine turtles, fish, moths and birds. A great deal of research is devoted to discovering how the magnetic compass sense of migratory birds works. A leading theory is that it depends on light-activated cryptochrome molecules in the retina. The proposed process depends on subatomic effects influenced by the orientation of the surrounding magnetic field. With a good deal of help from the experts, I learned a lot about the quantum chemistry involved – though I didn't find it at all easy!

I also had quite a lot of difficulty with the concept of a 'map'. It sounds like a simple enough thing but it's actually very complex and it doesn't help that scientists use the term in a wide variety of different and often ill-defined ways. Consider for example the difference between a map based on latitude and longitude, and the 'olfactory' maps supposedly used by pigeons. The latter might conceivably be based on a mosaic of smells or stable concentration gradients. Or what about a magnetic map based on some combination of the intensity, inclination or declination of the Earth's unstable magnetic field? We humans are now so reliant on maps that we have difficulty in grasping that safe navigation is possible without them. I suspect that a lot of the claims made about the use of 'maps' by animals result from our tendency to invoke a 'map' whenever we encounter some navigational feat that is hard to explain. In fact I'm not sure there's yet any really solid evidence of a 'map' outside the world of mammals. That said, some migratory birds do seem to be able to compensate for changes in longitude, and if that's true, they too may turn out to be map-users. And then of course there are those puzzling pigeons...

Did any unanswered questions surprise you?
It's not surprising, given the challenges of marine research, but I'm frustrated that we still know so little about how animals navigate at sea. We know that turtles, salmon and spiny lobsters can make good use of the Earth's magnetic field, but what about the amazing migratory journeys of humpback whales, great white sharks, bluefin tuna, or northern elephant seals – to name but a few? How they navigate successfully across the apparently featureless open ocean is still deeply mysterious. Humpback whales, for example, have been tracked as they follow astonishingly straight courses over thousands of miles. How do they do it? It seems quite likely that magnetism is involved but recent research suggests that they may also be making use of gravitational information. I would love to know the answers.

I would also like to know more about the role that the navigational circuits in the human brain play in other cognitive activities. They may contribute to our ability to imagine possible worlds and to generate new ideas. It would be really fascinating to understand what part our navigational skills play in our creative abilities. And there's a growing body of evidence that navigational circuits play an important part in the management of our social lives. In a 2015 experiment led by Rita Morais Tavares, people took part in a game that involved getting to know a cast of characters in a 'new town', while brain activity was monitored in an fMRI scanner. Choices and interactions based on the social standing of each character gave rise to changes in the relationships between them. Concurrent patterns of hippocampal activity suggested that the participants were navigating 'a social space framed by power and affiliation'. The authors think that the concept of social space is more than a mere metaphor: it may well 'reflect how the brain represents our position in the social world'. If so, people who struggle either to read social cues or to recall the outcomes of previous encounters will have a hard time constructing effective social maps, and that may play an important part in the many psychiatric illnesses that involve faulty social cognition.

Who did you most enjoy talking to when researching your book?
That's really hard to answer as I had so many enjoyable conversations. But it was a real privilege – and delight – to interview Rüdiger Wehner, perhaps the greatest living scientist working on animal navigation. He has spent 50-odd years exploring the astonishingly elaborate navigational toolkits of ants – especially the desert ant, Cataglyphis fortis, and has made many seminal discoveries. I spent a whole day with him at his apartment in Zürich while he patiently answered my questions. He's not only a brilliant scientist, but a wonderfully wise, cultivated and generous man.

Has writing the book changed you?
As I put it in the last chapter of Incredible Journeys: 'I have again and again been struck dumb with admiration by the extraordinary skills of the animal navigators that are its stars. Even if our own lives did not depend on the health and vitality of the planet we inhabit, the preservation of the almost infinitely complex web of life from which such wonders emerge is surely an ethical imperative'. The trouble is, I don't see how the political systems within which we operate can deliver the policy changes that are now so desperately needed – at least, not in time to save us. Do we then need some kind of revolution? Whether we want it or not, I suspect that a revolution is coming, and maybe soon, though what form it will take is still veiled from us – as is always the case.

'Labyrinths are a sort of contained, safe jeopardy'

Charlotte Higgins

Why do you think you have a 'longing for the labyrinth'?
I think, in general, labyrinths are very tempting places, no? Who has passed the entrance to a maze without wanting to test herself against it? Children love mazes and labyrinths: the fun of being lost, but not really being lost. A sort of contained, safe jeopardy. In my case, I was taken to Crete and Knossos when I was a child, and completely fell for the romance of the labyrinth of Greek myth. I went on to study classics at university. Ariadne, Theseus, Minos, the Minotaur – these are stories that still crowd my imagination.

I was struck by what a powerful metaphor the labyrinth is, for pretty much everything in life, and therefore everything in Psychology too. In the book, you quote your late friend Mrs Grammatiki: 'to be inside a maze or a labyrinth is to be bewildered, confused or afraid. But it is, nonetheless, also to be inside a structure. It is to be lost, but only up to a point.' Maybe everything is fundamentally a toss-up between beauty, pattern and order on the one hand, and chaos, fear and bewilderment on the other? Power and powerlessness, mastery and terror, the complex and the meaningless… to be lost-not-lost.
It's certainly true that once one starts to think about the labyrinth as a metaphor, you start to see it everywhere, in my experience... G.K. Chesterton would have talked of the universe as a labyrinth built by God, with God at the centre: he had the comfort of the sense of an ordered world even if humanity, with her myopic limits, can't trace those patterns fully. As a more-or-less godless person my terror, of course, is that there's no pattern, and that we live in boundless chaos. The labyrinth without an edge.

A safer course, for me, is to think of individual human lives as tracing a circuitous, labyrinthine path, whose pattern we cannot see from the inside, but make a certain sense when they are completed. Thinking back on writing Red Thread, it was palpably my mid-life book. It's always dangerous to make pretentious comparisons with Dante, but there was an element of being in a dark wood in the middle of my life. My mother died three months after it was published, and, though she wasn't ill while I was actually writing, on some level I was anticipating this truly devastating event, or somehow attempting to prepare for it. Half-consciously I knew that there was a crucial junction coming.

You describe your book as a 'winding journey down my imagination's shaded byways'. Does that approach ultimately allow you to impose order, to use stories as a way out of the labyrinth? Or do you simply delight in the detours?
Oh, both, for sure. The labyrinth can resemble the brain; the labyrinth, as built by Daedalus, is the kind of ur-creative object in Greek mythology, standing in for all kinds of artistic and imaginative ingenuity. The containing idea for Red Thread's unconventional structure – the book is a long series of intuitively linked passages – was the idea of creativity itself, the way that ideas emerge from each other as branching byways of the mind.

An important way of thinking about all this was to write about Arthur Evans's excavations, in the early 20th century, of Knossos, the site of the mythological labyrinth. He excavated a whole new civilisation – but, in a very rich and revealing way, he also imagined that civilisation into existence, projecting his own interior world on to the Bronze Age Mediterranean society he discovered. (This act of projection is surely one reason Freud was so interested in his work, aside from the fact that he sometimes used the idea of an 'excavation' of the mind to help explain psychoanalysis.) One of the ideas in the book is that excavation and creation are not so very different.

So yes, the book delights in its own detours, delights in setting traps and misdirection, and laying clues for the reader. But of course there is also an underlying structure, one that I'm not inclined to give away. The reader must figure that out for herself.

The book is called 'Red thread', as Ariadne gave to Theseus before he faced the Minotaur. At one point you write 'tug at a thread and everything could unravel'. Could you expand on what you mean, in terms of our psychology and lives?
I suppose a preoccupation of mine is of the slender membrane between a settled, prosperous life and complete chaos. The idea that you could undergo something like Oedipus, who began his day the respected and honoured king of Thebes and ended it self-blinded, exiled, widowed, reviled, the murderer of his father and the father of his mother's children. Not such a melodramatic idea, really, in the age of terrifying natural disasters, of the desperate situation of refugees and migrants, of the Covid-19 pandemic, and of increasing political and economic instability. Plenty of examples of that in 20th-century history, too.

What did meeting psychologists for the book, or reading psychology, help you to understand about yourself?
Well, one of the reasons for writing the book was that I lack any kind of sense of direction – I mean, literally, I get lost in the streets, I even get lost in people's houses. I can read a map and can navigate by landmark if I properly concentrate, but I am directionally challenged, let's say. I had a fascinating discussion and correspondence with Hugo Spiers, who directs the spatial cognition research group at UCL, and who trained with Nobel laureate John O'Keefe. Hugo was incredibly interesting on the complex relationship between different forms of memory, the hippocampus and prefrontal cortex, and sense of direction; I write about some of his work in Red Thread. Being unable to find your way home is often an early 'tell' for dementia, he informed me – which led to a brief panic! He was reassuring, though: some people are just better at navigation than others. It's also true, I have to admit, that I am lazy, and prefer to let my mind drift when walking through the streets. The entire conversation somehow left me at more peace with my own crummy navigation skills than I had been before – which, needless to say, are currently largely outsourced to my GPS signal.

As for how that translates into the rest of my life? I'd like to feel that after having these conversations and writing the book I was better able to absorb the knowledge that the future cannot be controlled. But that's optimistic.

'There are hundreds of strange signs…'

What got you interested in natural navigation? 
I've always enjoyed putting journeys together. From a young age, long before I knew the word navigation, I found it thrilling to think: I'm here, how can I get there?

Small journeys to the top of hills and across lakes as a child blossomed into expeditions up mountains and across oceans as an adult. By my mid-twenties I was taking on thousand kilometre expeditions. But I found that as the journeys got bigger, they became no more interesting. Sometimes the opposite; you can fly a small aircraft by looking out the window, but to take on big journeys you are legally forced to spend a lot of time staring at screens.

This led to my taking on much smaller journeys, using nature as my map and compass.

Can you give us some examples of how your view changed?
I can honestly say that I found the first attempt to cross a couple of kilometres of English woodland using the trees and clouds as my main compasses as exhilarating as flying solo across the Atlantic.

You work full time as a 'natural navigator', but what does that actually entail?
My day job has two parts: research and communication. And these two parts have several guises.

I have undertaken lots of journeys, but plenty of my research is delving into arcane places looking for clues and signs to how we can find our way without electronics. I garner inspiration and information from our ancestors and from the latest research.

At its best it is a process that feeds itself. I discovered a reference in Norse Lore to how the Vikings used whales and birds to establish their position at sea. This led to a small boat journey into the North Atlantic to prove it worked, which in turn yielded the academic article, 'Nature's Radar'. But that didn't pay any bills and, since I'm not funded by a university, my daily income relies on popularising some of these techniques. That expedition formed a few paragraphs of a book I wrote called How to Read Water, which became a New York Times bestseller.

I'm very fortunate that the books I've written seem have a global appeal; hopefully they speak to a universal curiosity. This allows me to continue doing what I do, which I am very grateful for. It turns out there are enough curious souls out there who want to know how to use a puddle as a compass!

Have you been properly lost?
My work has meant I have had to grow comfortable with the different shades of being lost, from pleasant sensation on a Sunday afternoon, to a terrifying feeling that my life was in danger.

Once when I was 19, I tried to climb a large active volcano in Indonesia with no navigation equipment at all. It was foolhardy. My friend got hypothermia near the summit and in the rush to get down to a safe temperature, I got us lost. We walked for three days without food and eventually found a remote village, more by luck than skill.

What is the strangest navigation method you have uncovered?
There are literally hundreds of strange signs we can use and that I have written about. For example, the size, colour and shape of tree leaves can all be used to make a compass.

But the strangest approach was one I encountered in a rainforest. A few years ago I travelled to the heart of Borneo to walk with the Penan Dayak in order to study their methods. The Dayak can travel large distances across the interior with no map, compass, GPS or smartphone, which is what we'd expect. But what I found surprising is that they did not refer to cardinal directions at all. Their frame of reference, their methodology, revolves around topography, gradient and water flow. They can orientate themselves and their landscape entirely through reference to uphill, downhill, upriver and downriver. It is so different to every other navigation approach I have ever studied that it still amazes me.

I asked one of the Dayak what they did when they felt lost. They told me that they walked to the top of a hill or mountain for a better view. 'But what if you're still surrounded by jungle at the top of the hill?', I asked. Their answer was simple, logical and beautiful. 'We just climb the tallest tree on top of that hill.'

BOX: Do you have a favourite account of being lost?

Maura O'Connor: My favourite is the story of the American tourist in Iceland. He was trying to get from the airport in Reykjavik to a hotel nearby and ended up driving 270 miles in the wrong direction because his GPS told him to. He even saw signs showing Reykjavik was in the other direction but he kept going! Why is our faith in technology so complete that we would doubt our direct experience – literally what we see with our own eyes? I think this question has a lot of implications in our era of fake news, conspiracy-mongering, Covid-19…

Michael Bond: Hansel and Gretel – although it's a fairy tale, it's a great metaphor for the universally terrifying experience of being lost in the woods.

Tristan Gooley: The Star Dust aircraft crash in the Andes in 1947. It has everything: mystery, science, intrigue, adventure, romance. The irony is it is mainly a story about us losing the aircraft, rather than the pilots or passengers themselves getting lost. They were lost, but didn't know it. For more than 50 years the world had no idea what had happened to Star Dust. It had just disappeared.

Conspiracy theorists will be disappointed that most people feel that science has solved the mystery, but they haven't all given up; do they ever?

I don't think it will spoil the story to reveal that the pilots thought they were one side of the Andes ridge, having cleared the peaks, because they had no awareness of the (then poorly understood) jet stream.

David Barrie: In Incredible Journeys I quote the great Italian writer Italo Calvino's account of being lost in a Russian forest. That's very gripping, but actually I'd rather talk about something different: the extraordinary navigational skills that enable some humans to find their way where others would assuredly be lost – using only their senses and native wit. One such account comes from Hugh Brady's wonderful book The Other Side of Eden in which he gives a spellbinding account of his experiences with Inuit hunters in the high Arctic in the early 1970s. He tells of a long journey by dog sled across the forbidding wilderness of northern Baffin Island – without printed map or compass, let alone GPS. Three days out, high in the mountains, his Inuit companion paused to consider their route. He drew a map in the snow. Then they set off again. Two days later they arrived at their destination. His Inuit guide asked Brody when he thought he'd last visited this place. Brody guessed three or four years. No, came the answer: I was last here in 1938. (In other words well over 30 years before.) Brody was astonished and asked him how he knew his way through the mountains. 'Because Inuit cannot get lost in their own land. If we have done a journey once, we can always do it again.'

Sadly, I understand that many young Inuit are turning their backs on the traditional skills of their ancestors and relying too heavily on GPS – sometimes with disastrous results. There is a lesson here for all of us. As we become more and more dependent on our electronic gadgets for finding our way around, our natural navigational skills are fast decaying, and we are also losing touch with the world around us [see Bohbot, V.D. (2020). Habitual use of GPS negatively impacts spatial memory during self-guided navigation. Scientific reports, 10(1), 1-14]. This is not a healthy development.