May 22, 2011


Earlier this year, I recommended Lawrence Rosenblum's See What I'm Saying, which explores the lesser-known aspects of sensation and cognition. What I didn't mention was that I had two of my English classes read an excerpt, then head out into the halls to test our echolocating skills. Since we had so little practice, we were terrible at it--but we could hear the possibilities. Navigational failure was a pedagogical success.

I was reminded of that experience when pointed by Maggie Koerth-Baker to this blog entry by neuroscientist Bradley Voytek.
We're used to thinking of our senses as being pretty shite: we can't see as well as eagles, we can't hear as well as bats, and we can't smell as well as dogs.

Or so we're used to thinking.

It turns out that humans can, in fact, detect as few as 2 photons entering the retina. Two. As in, one-plus-one.

It is often said that, under ideal conditions, a young, healthy person can see a candle flame from 30 miles away. That's like being able to see a candle in Times Square from Stamford, Connecticut. Or seeing a candle in Candlestick Park from Napa Valley.

Similarly, it appears that the limits to our threshold of hearing may actually be Brownian motion. That means that we can almost hear the random movements of atoms.
Voytek calls humans "inattentive superheroes," our skills fundamentally underdeveloped in a world full of noise. We underestimate the value of silence, of darkness, of time spent alone. We'd like to be more focused, but we don't know how--and we keep filling our lives with more things that siphon attention away.

Much of the siphoning is well-intentioned, an attempt to remind us--to alert us--to pay attention. You're rolling through a residential neighborhood, at the wheel of a two-ton death machine. In the corner of your eye, a yellow warning: "Children at Play." It's a safety measure that can be--and will be--easily ignored. And probably should be torn down.
The National Cooperative Highway Research Program, in its "Synthesis of Highway Practice No. 139," sternly advises that "non-uniform signs such as "CAUTION--CHILDREN AT PLAY," "SLOW--CHILDREN," or similar legends should not be permitted on any roadway at any time." Moreover, it warns that "the removal of any nonstandard signs should carry a high priority."

One of the things that is known, thanks to peer-reviewed science, is that increased traffic speeds (and volumes) increase the risk of children's injuries. But "Children at Play" signs are a symptom, rather than a cure--a sign of something larger that is out of whack, whether the lack of a pervasive safety culture in driving, a system that puts vehicular mobility ahead of neighborhood livability, or non-contextual street design. After all, it's roads, not signs, that tell people how to drive. People clamoring for "Children at Play" signs are often living on residential streets that are inordinately wide, lacking any kind of calming obstacles (from trees to "bulb-outs"), perhaps having unnecessary center-line markings--three factors that will boost vehicle speed more than any sign will lower them.
If, at our best, we're "inattentive superheroes," at our worst, we're overly confident, cognitively-deficient supervillains.
As is often the case in driving, when we meet the enemy, it is us. You want difficulty in judging spatial relations? Consider the research, by Dennis Shaffer, that showed people reporting 10-foot-long highway stripes to be two feet long. You want difficulty estimating speed? Consider this study, which found drivers underestimating their speed in the presence of children by upwards of 50 percent. You want exceeded sensory abilities? Consider the widespread phenomenon of "overdriving" one's headlights. You want trouble estimating distance? Ask any driver how many feet they'll need to stop, driving at 65 mph. You want impulsive? Who's reaching across the seat for that buzzing BlackBerry?

If "Children at Play" signs are ineffective at capturing our attention--or doubly ineffective when they do--what about other supposedly helpful road signs: speed limits, "Road Narrows," "Koala Crossing?" (We'll leave aside "One Way" for now.) What if they were gone--all gone? John Staddon points toward a possible future:
So what am I suggesting—abolishing signs and rules? A traffic free-for-all? Actually, I wouldn’t be the first to suggest that. A few European towns and neighborhoods--Drachten in Holland, fashionable Kensington High Street in London, Prince Charles’s village of Poundbury, and a few others--have even gone ahead and tried it. They’ve taken the apparently drastic step of eliminating traffic control more or less completely in a few high-traffic and pedestrian-dense areas. The intention is to create environments in which everyone is more focused, more cautious, and more considerate. Stop signs, stoplights, even sidewalks are mostly gone. The results, by all accounts, have been excellent: pedestrian accidents have been reduced by 40 percent or more in some places, and traffic flows no more slowly than before.
Of course, all of this could be moot once automobiles become truly auto. And then we can turn our attention toward more important things.

For some, it's even harder than usual to block out the tumult of the everyday. In the fourth part of a fascinating series, Marie Myung-Ok Lee describes how her autistic son was finally able to learn how to ride a bike.
After my husband and I bought him a bike with training wheels, he would sometimes sit on it for a minute or two, try to pedal, and then have a tantrum, hurling the bike in frustration. His classroom bike-riding lessons weren't going any better. At a school meeting, the consensus among his teachers and other professionals was that independent bike riding was something he'd probably never learn.
They probably would have been right, were it not for Lee's persistence in seeking out a remedy: high-grade marijuana.
[C]annabis not only mitigates J's pain, it also seems to help him to focus... [M]arijuana's effect on short-term memory allows a user to focus intently on a single sensation (that "Whooooaaaa, man... look at that flower" feeling). One feature of autism is a heightened, disordered, nondiscriminating sensitivity, so that autistics seem to see and feel and hear and smell everything at the same time.... But with cannabis (which also regulates anxiety and stress), I noticed that J had a much higher tolerance for activities that involve multiple steps, like unloading the dishwasher.

Bicycling, when you think about it, involves myriad functions: coordination of gross motor movement with the vestibular, visual, and proprioceptive systems that regulate balance. On a nice weekend I brought J, his bike, his helmet, and a wrench to a nearby private school that has a bunch of wide, paved paths. I removed the training wheels from his bike, put him on it, and gave him a push, figuring that once he realized how good it felt to bike--to move along on his own power--he was going to love it. He pedaled and immediately tipped over, laughing, as he was expecting the training wheels to be there holding him up. But after a few tries, he started to get it. And before the afternoon was over, he was biking independently.
Lee's story is inspiring and infuriating; our federal government's increasingly bizarre insistence on persecuting medical marijuana users made her take unnecessary personal and medical risks. In a saner world, her doctor would have been able to prescribe a standard, fully-tested treatment, and her son's triumph would have been heartwarmingly ordinary.

It may tax your 21st-century attention span, but start with the first part and keep going until you're done.

When I was young, I could get so wrapped up in a book (or so focused on my Legos) that I'd shut out the world. Maybe that's why I've never been interested in trying pot: that "Whooooaaaa, man..." sensation may not sit well with a brain perfectly comfortable managing its own focal point.

When we let someone else sort the signal from the noise, we risk missing the whole signal. Call it a "filter bubble," algorithmically facilitated attention-narrowing.

Just because you can see a photon from space, doesn't mean you should drive without your glasses.

Driverless cars? Soon. But not quite yet.

No comments: