For the first time, WSU researchers created a laboratory experiment that simulates how sleep loss affects critical aspects of decision making in high-stakes, real-world situations. Their results provide a new understanding of how going without sleep for long periods can lead doctors, first responders, military personnel and others in a crisis situation to make catastrophic decisions.
Overcoming challenge of lab research
Recent history is full of examples of the sometimes devastating consequences of people operating without enough sleep.
Investigations into the Chernobyl nuclear power plant meltdown in Ukraine, the grounding of the Exxon Valdez oil tanker and the explosion of the space shuttle Challenger all concluded that sleep-deprived operators played a role in causing the accidents.
A long-standing conundrum for sleep scientists has been creating a controlled lab situation that sufficiently simulates the circumstances leading to severe lapses in real-world judgment. Previous laboratory research consistently showed sleep loss degrades attention, but its effects on demanding tests of cognition like decision making appeared to be relatively small.
"So there has been a disconnect between decision making in the lab where the effects of sleep loss appeared to be minimal and decision making in the real world where sleep loss can lead to big problems," said Paul Whitney, WSU associate dean and professor of psychology. "Our goal was to bridge the gap and capture the essential elements of real-world decision making in a laboratory experiment."
Adapting to feedback crucial
In a natural context, decision making is a dynamic process that requires a person to learn what is going on nearby as a result of his or her actions and changing circumstances. A surgeon, for instance, might notice a change in a patient's vital signs midway through a procedure. The surgeon can then use this feedback decide a better course of action.
"A novel aspect of this study was using a simple laboratory task that captures the essential aspect of real-world decision making of adapting to new information in a changing situation," said John Hinson, professor of psychology. "Prior studies of sleep loss and decision making have not realized how important adapting to changing circumstances is in determining when sleep loss will lead to decision making failures."
Whitney, Hinson and Hans Van Dongen, director of the WSU Sleep and Performance Research Center at WSU Spokane, along with Melinda Jackson, now of the RMIT University, Victoria, Australia, recruited 26 healthy adults to take part in their study conducted at the Spokane sleep center.
Thirteen of the participants were randomly selected to go 62 hours without sleep two days into the study while the other half of the group was allowed to rest. For six days and nights, the participants lived in a hotel-like laboratory where they performed a specially designed reversal learning task to test their ability to use feedback to guide future decisions.
Mid-study switch confounds sleep deprived
In the task, subjects were shown a series of numbers that, unknown to them, were pre-assigned to have either a "go" (response) or "no go" (non-response) value. They had less than a second to decide whether or not to respond to each number shown.
Every time they correctly identified a number with a "go" value, they received a fictitious monetary reward. Errors resulted in a loss.
After a while, both the sleep-deprived group and the controls started to catch on and selected the right numbers. Then the tricky part came. The researchers reversed the contingencies so that participants had to withhold a response to the "go" numbers and respond to the "no go" numbers.
The switch confounded the sleep deprived participants. Even after being shown 40 numbers with reversed contingencies, they had almost zero success. On the other hand, the rested participants would catch on to the switch within 8-16 numbers.
Implications of sleep-loss risk
The data show that no matter how hard a person wants to make the right choice, sleep loss does something to the brain that simply prevents it from effectively using feedback. The study provides a new tool for investigating how sleep deprivation produces decision errors in real-life situations where information emerges over time.
"People in high-stakes environments are held accountable for their actions when they are fatigued just like everyone else," Van Dongen said. "However, we now know that when someone is sleep-deprived their brain simply can't process feedback from their actions and changing circumstances.
"Our findings tell us that putting sleep-deprived people in perilous environments is an inherently risky business and raises a number of medical, legal and financial implications," he said.
Welcome to SUV System Ltd!
SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.
We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.
SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com
SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc
we are focus on the following fields,and hope we can help you.
Transistors Freescale Industrial IC ELPIDA IC MURATA IC IR transistor MAXIM IC Fast Recovery Diodes ROHM Resistors IR Diodes INTERSIL IC HARRIS IC Xilinx IC Zener Diodes Military IC AD IC NXP Diodes Connectors NEC Diodes About US FAIRCHILD diodes PANASONIC Resistors AVX Resistors Atmel IC Switching Diodes LITTELFUSE Diodes Rectifier Diodes Diodes Inc LED part components NXP Transistors ST Diodes ST Transistors Texas Instruments(TI) IC Vishay resistors Civil IC Current Sensors Resistors Chip Fuses Freescale Semiconductor Capacitor High Precision Resistors