Week 19 (12 – 16 March) Problem Solving & Decision Making

Problem Solving & Decision Making

This has been a subject that has long fascinated me, but any time I delve into the literature, I am left feeling deeply bored. I guess, I want more to solve puzzles and problems than read about how psychologists have dissected how we solve problems.

That is until recently. Two years ago in an airport bookstore in Bangkok, I found the the book, How We Decide, by Jonah Lehrer. It is a fascinating volume, quite outside of the AP Psychology syllabus, which is too bad because it sheds more light on problem solving and decision making than the dry discussions of expertise and heuristics and biases found in our textbook does.

In the book, Lehrer reviews the recent findings in neurocognitive psychology regarding both problem solving and decision making. He takes the, by now, conventional approach of relating an interesting personal narrative of someone experiencing the topic of the chapter, and then, he discusses the neurology and cognitive psychology that explains the behavior.

Problem Solving

Victims of the Mann Gulch Fire (from http://www.honoringheroes.com)

He relates the story of Wag Dodge who as a smokejumper in 1940’s and 1950’s had jumped with his crew into the Mann Gulch river valley to fight a small fire. Upon their arrival, however, they found that the fire had gotten out of control. Dodge did not trust the fire; it was much larger than they were told but heading away from them.

Since they were too few to effectively fight a fire of such a size, the men moved down into the gulch and simply watched the blaze. As evening fell, the wind shifted and started blowing the fire towards them. At this point, the flames began leaping 60 meters into the air, and the fire grew to 1,500 meters wide, and almost 1,000 meters deep. At its center, the fire was over 1,000° Celsius — hot enough to melt rocks. Dodge ordered his men to drop their gear and retreat up the steep side of the gorge.

At this point the fire covered 1,200 hectares in 10 minutes. The fire was now a firestorm, moving at over 60 km/hr and roaring like a freight train. The rising heat started sucking the air in front of it causing the men to run into a head wind slowing them even further. Dodge could feel the heat of the fire scorching his back.

Diagram of the Mann Gulch Fire (from http://wildfiretoday.com)

Dodge yelled for his men to stop and follow his directions, but they could not hear him over the roar of the flames and wind. He realized they could not outrun the fire. There was no escape. Then, he took out his matches and lit a grass fire. After the flames burned an area large enough to lie in, he covered himself with his fire blanket (designed to resist flame and heat), and waited for the fire to pass over him.

Thirteen of the sixteen men there died. The fire overtook them as they climbed the ridge. Dodge lived through the ordeal because the flames could not touch him because there was nothing left around him to burn. The buffer was enough to allow his blanket to insulate against the terrific heat. Two others did essentially the same thing as he did: they had wedged themselves into rocky outcroppings and covered themselves with their fire blankets.

How did Dodge come up with his unique method of surviving the fire? He had no algorithm or heuristic to guide him, although smokejumpers now learn his technique as part of their training. First, he contained his panic which causes you to experience perceptual narrowing where you begin to focus only on the essentials. He realized that their initial instinct to run from the fire, even if fueled by their adrenaline, would not save them. Then, his limbic system (seat of emotions) stopped interfering with his thoughts allowing him to use his prefrontal cortex to evaluate his options. Once he thought of his solution, he realized he had nothing to loose.

Ariel photo of Mann Gulch showing where the bodies were found (from http://www.fireleadership.gov)

A body of one of the smokejumpers is carried from Mann Gulch (from http://www.bozeman-magpie.com)

Robert Sulley in 2005, the last survivor of the fire (from http://www.whitefishpilot.com)

A Wobbler’s Story

This is the blog post I promised about the woman who lost her sense of balance & then recovered it. This is one of my most favorite case studies. It is remarkable in what it demonstrates in our resilience.

Cheryl always feels like she is falling. There is never a moment in her life that she does not experience the sensation of falling. When she is lying flat in bed, she feels as if she is falling. When she is sitting in a chair, she feels as if she is falling. When she stands, she feels as if she is falling. And when she falls and is lying in a heap on the ground, she still feels like she is falling.

Not only does she constantly have the sensation of falling, but when she moves, everything moves. She describes it as eve

Vestibular System

Inner ear, showing semi-circular canals Image via Wikipedia

rything seeming to be made of Jell-O or being wiggly. Moving objects seem to bounce. Rooms spin.

She can not be still because she is constantly trying to catch her balance. Walking is nearly impossible. Standing more so.

Cheryl lost her sense of balance when she was given the antibiotic gentamicin for a post-operative infection.  Gentamicin is cheap & effective, but when taken for too long of a period of time, it will destroy the inner ear causing hearing loss, ringing in the ears, & a loss of balance

. Cheryl can still hear, but she has ringing in her ears & no sense of balance. She was 39 years old. People who suffer a loss of balance due to gentamicin call themselves Wobblers.

Balance relies on two separate sets of inputs. First are the signals that come from our semicircular canals. These tell us which way is up and how badly we’ve gotten off of perpendicular. They are responsible for that lingering disquieting spinning sensation after having been spun around.Cheryl’s semi-circular canals were destroyed by the gentamicin.

The second source of balance information is from the eyes. When we can see the horizon and other horizontal lines, we can tell if we’re upright or not. Motion sickness comes from this source. Oddly, Cheryl’s visual support for her balance is easily disturbed by looking at zig-zagging lines or other designs that are not square or imitate depth. Consequently, Cheryl is constantly fatigued. Her brain is working overtime to keep her relatively balanced taking away resources used for calculating, reasoning, or even communicating.

Luckily, Cheryl found out about a neuroplastician named, Paul Bach-y-Rita. He had developed ways of retraining the brain to use other cortical areas to compensate for deficits. His has helped people who have had strokes, accidents, and birth defects. And, he had a

Paul Bach-y-Rita (1934 - 2006)

possible solution for Cheryl.

His idea was to help her bypass the semi-circular canals & the cortical area that interpreted their input. He realized that she probably was still getting signals from the canals, but that it was “noisy” filled with bad information and perhaps some good information. The problem was that the brain didn’t know which was which, & then when she tried to match her faulty information from her semi-circular canals up with the accurate information from her eyes, her brain didn’t know which to believe. So, Bach-y-Rita created a helmet that was lined with sensors. These sensors would detect the position of her head. He fed this information into a small thin device that she would press to her tongue. It was covered with electrodes. When her head tilted one way, that area on her tongue with tingle with gentle electrical energy. When it tilted another, her tongue would tingle in another place. In this way, her brain could start to learn which signals were accurate and which were not, & then begin to match up the accurate information and ignore the inaccurate.

It took her only a couple of hours to get the hang of it. She was able to maintain her balance while the helmet was on her head & the tongue tingler was in her mouth. She was even able to maintain her balance for a few minutes afterward. So, she began to wear it for a couple of hours everyday, & the length of time that she could maintain her balance increased… exponentially. It soon began to stretch into days.

They sent her home with the device. She wore it whenever the effect began to wear off, & soon it lasted weeks. Then, it was months. Now, she hasn’t needed it for years. In essence, she was cured. Her brain had adapted to her new sensory input for balance! It was a miracle.

A tongue sensor that is similar to the one Cheryl wore.

An apparatus similar to the one Cheryl used