The Brainstorm Book Extract: when we walk, we are extending our range of experiences of this complicated world

We overlook at our peril the gains to be made from walking, for our health, for our mood, for our clarity of mind. Many of us live now in a deeply unnatural environment, where we spend long periods of the day sitting with our eyes focused on screens, perhaps a half-metre or so from our eyes.

When we stand up, and then walk around and move about, our posture changes, with our torso and spinal column shifting to a single vertical axis from our head down through our back, and, through our legs and feet, contacting the ground.

By contrast, when we sit, the weight of our body trunk is largely concentrated on the lower back, and in particular, on the coccyx, that little collection of bones that comprises our vestigial human tail. The coccyx anchors a remarkable lattice of tendons and muscles extending across the spine and down the upper legs in particular, the gluteus muscles of the upper thighs, which are vital for walking. Little wonder that lower-back pain is one of the most common ailments in the developed world.

A RTÉ Brainstorm video on back pain

How silly, then, that the remedy – to regularly get up out of your seat and walk about – is so little understood or practised. Long periods of immobility also cause changes in muscle: fatty deposits build up in leg muscle, and, as we age, we lose muscle mass in part because of our immobility ('sarcopenia'). There are many other changes too: our blood pressure changes, as does our metabolic rate (the rate at which we burn energy).

But when we stand up, things suddenly change in brain and body: we become ‘cognitively mobile’, our minds are in movement, our heads swivel, our eyes dart about. Our brain activity changes when we move about, with electrical brain rhythms that were previously quiescent now engaged and active. We become more alert, our breathing changes, and our brains and bodies are readied for action. The French philosopher Jean- Jacques Rousseau commented that "I can only meditate when I am walking. When I stop, I cease to think; my mind only works with my legs".

From RTÉ Archives, a 1993 episode of Hill Walks with Jim Sherwin visiting Clare Island off the coast of Co Mayo

Here’s a walking memory of mine: I’m at a student conference in Belfast during the dreary and seemingly never-ending 1980s. I take a long walk up the Malone Road, past Queen’s University into the centre of town. I pass through the numerous security cordons. Young soldiers with serious weapons are patrolling the city, looking in shopping bags for bombs and guns, talking nervously to each other in English accents. There’s plenty of tension in the air. The Loyalist politician Ian Paisley’s campaigning against the Anglo-Irish Agreement is a constant backdrop, as are the terrible atrocities, the many bombings and murders. The city is alive, though. A city is hard to kill.

When I cast my mind back over this walk on my first visit to Belfast, I remember that I walked past the much-bombed Europa Hotel. I then walked east toward Botanic Avenue, and then took a long loop back around the streets and roads to the rear of the Europa Hotel. Why this route? Just because I could; that's what being on foot does for you. It’s early Saturday afternoon, the weather is grey, and there’s a hint of rain in the air.

From RTÉ Radio 1's Arena, a walk around the Dublin of James Joyce, Oscar Wilde and WB Yeats with Colm Tóibín to mark the publication of his new book Mad Bad and Dangerous to Know: The Fathers of Wilde, Yeats and Joyce

Wandering about, I accidentally find myself walking on Sandy Row, the Loyalist epicentre of Belfast. The murals are amazing, and a little frightening, to someone from the sedate and peaceful south. I walk quickly on, eventually connecting with the Lisburn Road, and finally find my way back to where we students were all staying on the Malone Road. Here, in Belfast, a walk is a walk into a past that is still present; as the old maxim has it, "the past hasn’t even passed".

Wrapped up in this little personal journey are many of the elements of the hidden story of walking: mental time-travel to recall details, reminiscences about a walk, orientation and successful navigation through an alien urban environment, the little frisson of fear that still comes to me when I remember the security cordons and the murals. We now know that the brain systems relating to all of these functions are in constant communication and support each other’s functioning. And, crucially, these brain systems are not perfect.

From RTÉ Radio 1's Today with Miriam O'Callaghan, interview with Shane O'Mara about his new book In Praise Of Walking

My memory has tricked me a little. It has simplified the route, and left out significant details. I remember Botanic Avenue as being almost opposite the Europa Hotel. It's not, as a look at a map tells me. Botanic Avenue is at an acute angle that runs on to Great Victoria Street, which is actually where the Europa Hotel is. And, weirdly, I have excised most of the detail about the relative location of Sandy Row and the Europa Hotel. I remember Sandy Row as more or less directly behind the Europa. It's not: Sandy Row is further south than that. I am left to imperfectly recall the gists of locations, places, things; I do not possess a faithful video recording somewhere in my brain of the route I took all those years ago.

Shane O'Mara, author of In Praise Of Walking. Photo: Bríd O'Donovan

This is the key point underlying our episodic and event memories: they are imperfect, gist-like, extracting meaning, focusing on certain salient points, and ignoring others. There is more information out in the environment than our mobile minds can capture, and more than we need to know. How we move, what we look at, who we talk to, what we feel as we move: these are central components of our experiences. They might enter into our recall and be laid down as traces in our brains.

We are not disembodied brains travelling through space and time: we feel the ground beneath our feet, the rain on our face; perhaps peering into the unknown, but in doing so we are extending our range of experiences of this complicated world. And all the while we are silently creating memories of where we have been, and making maps of the world we have experienced.

This is an extract from In Praise of Walking by Shane O'Mara (Bodley Head). Professor Shane O'Mara is Professor of Experimental Brain Research at Trinity College Dublin and Principal Investigator and former Director of the Trinity College Institute of Neuroscience.    

The views expressed here are those of the author and do not represent or reflect the views of RTÉ