Editor's note: In the Human Factor, we profile survivors who have overcome the odds. Confronting a life obstacle -- injury, illness or other hardship -- they tapped their inner strength and found resilience they didn't know they possessed. This week, author Alexandra Horowitz introduces us to the world we're not seeing. Read more in Horowitz's book "On Looking."
(CNN) -- What do you see when you walk to work, take yourself or your child to school, run to the store or head around the block with your dog?
Chances are, not much at all.
Evolution in humans has refined our ability to selectively attend to one stimulus and ignore all others; in this case, most of the myriad of stimuli that bombards you on the street, from people and pigeons to sounds and smells.
This capacity is useful, and lets us "concentrate" when we need to. But it also means that we spend a lot of time ignoring the richness of the world around us.
I study dog cognition, and to do so I spend a good amount of time observing dog behavior; on top of that, I live with two dogs who compel me to bring them out for walks a few times a day.
After some thousands of these walks and observations, I began realizing just how different "a walk" is for a dog and her person. For a dog, an animal whose primary sense is olfaction, the street is made up not of sights to see but of smells to smell. Indeed, being focused on odors -- which themselves require air to move, or a surface to light on -- means that for my dogs, the street outside our apartment building is different each time we step out the door.
Walking with dogs lets me see how little of the street I was experiencing most of the time. As familiar as my own block felt to me, I was mostly ignorant of what was on it.
I wondered what might other peoples' experience or interest let them see on my street that I routinely miss? In the past two years, I've taken dozens of walks with people whose constitution or expertise enables them to see differently (11 of these walks are described in "On Looking").
The urban sociologist Fred Kent and I noticed how well pedestrians unconsciously adjust their paths to navigate around each other -- except for the texters, noses pointed to the ground, who routinely bumped into people.
A naturalist, Charley Eiseman, showed me how every surface, from leaf to sidewalk crack, has an insect whose universe is centered there.
Walking with the illustrator Maira Kalman let me see the elegance in a couch placed incongruously among garbage bags and highlighted the kinds of personal, private and public spaces we navigate in the city.
These walks stay with me now on every walk I take in New York. Just today, because I walked with the urban wildlife expert John Hadidian, I noticed that a pipe affixing a traffic light to its pole was hosting a slew of nesting sparrows.
Given a lens to notice lettering styles by the typographer Paul Shaw, I counted six distinct serifed fonts in the lobby of the building where I work, punctuated by only one word -- EXIT -- entirely without serifs.
I noticed the standpipes (colored red, green, gold and one red with yellow caps) which my son, at the time 19 months old, pointed out to me, and which are evidence of a building six stories or higher.
From walking with Dr. Bennett Lorber and physical therapist Evan Johnson, I saw how a woman's pants, bunched up at the outside of her leg more than on the inside, revealed her bowleggedness and slight swagger.
And I felt the change of breeze from a slight headwind to a hair-ruffling side-wind as I crossed an intersection, because I walked with Arlene Gordon. Arlene went blind as an adult, and what she showed me was how much of the block she still sees, four decades after becoming blind.
She saw the intersections we approached by experiencing the changes of airflow that hit her. And as we walked, she used sound to draw a picture of the space around her. Through the tap of her cane, which, like an echolocating bat, sends a small sound out into the world, she could detect the size and constituents of the space through which she was walking.
As we neared an awning overhanging the sidewalk, she heard the awning -- because the cane-tap sound bounced back at her changed, closer. After we passed under it, I also could hear the sound changing, dribbling into the wide sky above us.
All of these walkers showed me that there are plenty of details to see on an ordinary walk around the block -- if only we bother to turn our attention away from our phones and headphones. There is no mandate to see all the time, but the reality in front of our noses, made visible to me by these people, is well worth the look.