Q. Fear of being lost seems to be hardwired in the human brain, yet it’s particularly difficult to know why lost people make the decisions they do. Now researchers have been able to identify predictable behaviors that could help rescuers narrow their search. What are some of them?
A. Lost people rarely do much to help themselves, and often make matters worse by continuing to move, “which substantially reduces the chance of being found alive,” says Michael Boyd in “New Scientist” magazine. The urge to move is understandable, triggered by fear, and with a heightened level of stress, cognitive functions needed for wayfinding decline. “Lost people have been seen walking trance-like past search parties, or running off and having to be chased down and tackled.”
Available records suggest that “certain tendencies are universal, intuitive to all humans in unfamiliar landscapes.” We are drawn to boundaries — a forest margin, a drainage ditch — and overall, most lost people found alive end up in a building or on what rescuers call a travel aid, such as a road, track or path. But different types of people get lost in different ways, depending on their age, gender, and mental state. For example, solo male hikers travel the farthest of all, and children are less likely than adults to keep moving, which explains why 96% of them are found alive compared with 75% of adults.
The first to study how children navigate, psychologist Ed Cornell and his colleague Donald Heth found that, when left alone to roam, children traveled much farther than anyone thought and wandered and dawdled rather than going directly to the target location. Their detailed report enabled a search team to find a missing 3-year-old boy “minutes away from dying of hypothermia.”
Q. With their hypersensitivity to odors, dogs have been known to detect the subtle smell of disease in their owners. How is this remarkable ability being put to use in tree orchards?
A. Dogs have been able to sniff out the pandemic and economically severe bacterial disease of citrus trees called huanglongbing, reports “Science” magazine. The dogs were first trained by positive reinforcement on potted citrus plants and gradually moved up to orchard conditions. “The dogs detected 30-day-old infections compared with genetic testing that only started to identify infections 3 months after insect-vectored transmission. If two dogs were used, detection accuracies of 100% were achieved….” Researchers estimate that “dogs could save up to 92% of the trees in an orchard by early detection followed by removal of individual infected trees.”
Q. Have you ever walked on a stopped escalator and found the experience weird? Why is that?
A. Escalators, ultimately, are staircases that move, yet there’s something disorienting about walking up (or down) a stopped escalator, says Dan Lewis on his “Now I Know” website. Some believe that slightly higher escalator stairs account for the feeling, but when researchers explored the issue further, they found otherwise.
Using a mobile sled, they had participants step onto it from a stationary platform: Ten times the sled wasn’t moving, 20 times it was, and on the 31st step, having been informed the sled was stopped, the participants were told to walk onto it again. Anecdotally and unprompted, many said it felt similar to stepping onto a stopped escalator.
Since no stairs were involved, something other than their height had to be at work. Muscle memory is the key, the research team concluded: Our brains — at a subconscious level — are telling our legs and knees and feet to take steps. “We’re on autopilot in a sense,” Lewis explains. “… by and large, the motor system simply approaches the escalator as if those stairs were going to start moving. A few steps in, we compensate for the mistake, but at that point, the odd stair height or staircase angle keeps the walk disorienting.”