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Ego Depletion, Motivation and Attention: A New Model of Self-Control

Willpower is a limited resource easily drained by everyday activity.

The human brain is fickle when it comes to commitments. Between 60 and 80 percent of people don’t use their gym memberships. Most diets work at first but backfire in the long run. According to a 2007 survey conducted by the British psychologist Richard Wiseman, about 88 percent of New Year’s resolutions end in failure.

Given how widespread our broken pledges are, it’s no surprise that psychologists study human willpower. Florida State University Professor of Psychology Roy Baumeister is one of the main figures in this area of study. His research on willpower began in the late 1990s with a few papers demonstrating that when people exert willpower, self-control, persistence and rationality founder. Willpower, he discovered, was a limited resource easily drained by everyday activity.

For example, in one study Baumeister and three colleagues deprived participants of food for several hours and then exposed them to the delectable smell and sight of chocolate chip cookies and chocolate candies. The sweet tease mattered. Participants not allowed to indulge (they ate radishes instead) quit faster on unsolvable puzzles than participants who devoured the tasty treats.

More recently, Baumeister teamed with Kathleen Vohs and other colleagues to investigate how decision-making impairs self-control. In a clever experiment they presented one group of participants with a table full of products - colored pens, scented candles, popular magazines, and colored t-shirts - and asked them to “indicate the extent to which they had used each product in the past.” The second group had their work cut out for them. The researchers gave them the same list of products but instructed them to carefully choose between two different versions of each product: a white t-shirt vs. a black t-shirt, a red pen vs. a purple pen, etc. Would all the choices deplete their willpower?

When both groups dipped their hands in frigid ice water Baumeister, Vohs and their research team found that the second group gave up sooner than the first. “Making all those choices,” Baumeister concludes in Willpower: Rediscovering the Greatest Human Strength, a recent book he co-authored with John Tierney that brings together over a decade of his research, “had apparently sapped their willpower, and the effect showed up again in other decision-making exercises.”

In other words, human willpower is exhaustible. Under this paradigm, exercising willpower in one instance reduces our ability to decide optimally, exert self-control or perform well on tasks in proceeding instances. Willpower is like a muscle, when it’s depleted – what Baumeister termed “ego depletion” – we suffer the consequences. 

This might not be the whole picture, however. A brand new paper by Michael Inzlicht (University of Toronto) and Brandon J. Schmeichel (Texas A&M University) propose that, “[ego depletion] is not some mysterious result of lost self-control resources but rather the result of shifts in motivation, attention, and emotion.”

Inzlicht and Schmeichel outline several studies that hint at their new framework. In one conducted by Mark Muraven participants performed tasks designed to induce ego-depletion (a thought suppression task, memory task or puzzles). Here was the key: Muraven told half of the participants that the study was designed to provide scientific evidence for new therapies for patients with Alzheimer’s disease. He told the other condition to just try their best at the task. With the health of Alzheimer patients on the line, participants in the first condition outperformed the control condition. A simple motivational incentive eliminated ego depletion.

There are other reasons to believe that ego-depletion might not be about “resource depletion.” A few studies provide evidence that participants who work hard on an initial task feel justified in slacking off during subsequent tasks. Research from Veronika Job, Carol Dweck and Gregory Walton even found that participants who believed that willpower is unlimited showed fewer signs of ego depletion compared to participants who thought willpower is limited, suggesting that reduced self-control is a function of people’s folk psychological beliefs. Taken together, our struggles with willpower might be a struggle with motivation and perception.

Inzlicht and Schmeichel also theorize that previous models of depletion result from shifting attention. They explain it this way. We exert self-control when there is a gap between what we want (desired states) and what we are engaged in (current states). For instance, self-control kicks in when we want to keep drinking but realize that we have to drive home; this monitoring system is especially active when there are severe consequences between pursuing a desired state over a current state.

Since initial acts of control lead attention to wonder, participants in the lab who solve puzzles, decide between products or try not to think of white elephants will pay less attention to the need to control and more on what’s gratifying. It’s not that they cannot control themselves; it’s that they temporarily “forget” that they ought to focus their attention on self-control.

Motivation and attention are, of course, interdependent, “[The] shift in motivation away from restraint and towards gratification is accompanied by a parallel shift in attention away from cues signaling the need to control and towards cues signaling the possibility of reward.” However, it is unclear which way the casual arrows points.

What is apparent is that a decade worth of research on willpower is incomplete. Inzlicht and Schmeichel aren’t in the business of destroying paradigms. They emphasize that previous research by Baumeister and colleagues is valuable and state that they’ve contributed to it. But they advise psychologists to understand self-control and its depletion at a more mechanical level. “That self-control exertion at Time 1 affects self-control at Time 2 has been replicated over 100 separate times,” they affirm. “Now we need to gain a more precise understanding of why that is.”

Image via Jim David/shuttershock

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The psychological scars a traumatic experience can leave behind may have a more profound effect on a person than the original traumatic experience. Long after an acute emergency is resolved, victims of post-traumatic stress disorder (PTSD) continue to suffer its consequences.

In the U.S. some 30 million patients are annually treated in emergency departments (EDs) for a range of traumatic injuries. Add to that urgent admissions to the ED with the onset of COVID-19 symptoms. Health experts predict that some 10 percent to 15 percent of these people will develop long-lasting PTSD within a year of the initial incident. While there are interventions that can help individuals avoid PTSD, there's been no reliable way to identify those most likely to need it.

That may now have changed. A multi-disciplinary team of researchers has developed a method for predicting who is most likely to develop PTSD after a traumatic emergency-room experience. Their study is published in the journal Nature Medicine.

70 data points and machine learning

nurse wrapping patient's arm

Image source: Creators Collective/Unsplash

Study lead author Katharina Schultebraucks of Columbia University's Department Vagelos College of Physicians and Surgeons says:

"For many trauma patients, the ED visit is often their sole contact with the health care system. The time immediately after a traumatic injury is a critical window for identifying people at risk for PTSD and arranging appropriate follow-up treatment. The earlier we can treat those at risk, the better the likely outcomes."

The new PTSD test uses machine learning and 70 clinical data points plus a clinical stress-level assessment to develop a PTSD score for an individual that identifies their risk of acquiring the condition.

Among the 70 data points are stress hormone levels, inflammatory signals, high blood pressure, and an anxiety-level assessment. Says Schultebraucks, "We selected measures that are routinely collected in the ED and logged in the electronic medical record, plus answers to a few short questions about the psychological stress response. The idea was to create a tool that would be universally available and would add little burden to ED personnel."

Researchers used data from adult trauma survivors in Atlanta, Georgia (377 individuals) and New York City (221 individuals) to test their system.

Of this cohort, 90 percent of those predicted to be at high risk developed long-lasting PTSD symptoms within a year of the initial traumatic event — just 5 percent of people who never developed PTSD symptoms had been erroneously identified as being at risk.

On the other side of the coin, 29 percent of individuals were 'false negatives," tagged by the algorithm as not being at risk of PTSD, but then developing symptoms.

Going forward

person leaning their head on another's shoulder

Image source: Külli Kittus/Unsplash

Schultebraucks looks forward to more testing as the researchers continue to refine their algorithm and to instill confidence in the approach among ED clinicians: "Because previous models for predicting PTSD risk have not been validated in independent samples like our model, they haven't been adopted in clinical practice." She expects that, "Testing and validation of our model in larger samples will be necessary for the algorithm to be ready-to-use in the general population."

"Currently only 7% of level-1 trauma centers routinely screen for PTSD," notes Schultebraucks. "We hope that the algorithm will provide ED clinicians with a rapid, automatic readout that they could use for discharge planning and the prevention of PTSD." She envisions the algorithm being implemented in the future as a feature of electronic medical records.

The researchers also plan to test their algorithm at predicting PTSD in people whose traumatic experiences come in the form of health events such as heart attacks and strokes, as opposed to visits to the emergency department.

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