How making numerous choices can lead to mental brain drain

December 1, 2016

By Peter J. McDonnell, MD

By Peter J. McDonnell, MD


If there is one thing we ophthalmologists do a lot of, it is making decisions. In most ophthalmic subspecialties we have learned to be very efficient in our clinics, allowing us to see more patients per day than do most of our physician colleagues (probably dermatologists and otolaryngologists are up there with us). And seeing more patients with eye problems translates into our making more decisions:

-       Does this patient need surgery?

-       Which IOL should I use?

-       Given the cost and (possibly) other differences, which anti-VEGF agent should I recommend for injection into this person’s eye?

-       Is this angle occludable?

-       Is the change in this visual field from last visit sufficient to cause me to declare this patient to have progressive changes justifying glaucoma filtration surgery or can I hold off?

I point this out because of the body of research indicating that human beings can make only so many high-quality decisions per day. After a while, we develop “decision fatigue.” This phenomenon occurs because “no matter how rational and high-minded you try to be, you can’t make decision after decision without paying a biological price. It’s different from ordinary physical fatigue – you’re not consciously aware of being tired – but you’re low on mental energy. The more choices you make throughout the day, the harder each one becomes for your brain and eventually it looks for shortcuts.”1

Psychologists have carried out many experiments that show that our judgments are affected by whether we have recently been forced to make a substantial number of decisions. We have less self-control (we can tolerate having our hand in ice water for much shorter periods), we have less will power and we can sometimes make snap, impetuous decisions that we regret later.


In real-life, this phenomenon is demonstrated to play out in several ways. Criminals are more likely to receive parole from the parole board if they appear in the morning (when the board members have yet to make many decisions) than when they appear later in the day, even if later in the day the prisoners had less serious offenses. Shoppers make decisions based on a single dimension (“just give me the cheapest”) and car buyers are more likely to become prey to sales pitches (“just give the me undercoating and let me out of here”). By altering the order in which someone ordering a new car is presented with the options packages from which they must choose, the customers can be steered (pun intended) into spending an average of $2,000 more on their purchase.

Brain glucose levels are reported to be important regulators of this effect. In the laboratory experiments, a tasty sugary drink undid the decision fatigue while an artificially sweetened beverage did not. Prisoners appearing before the parole board just before a midmorning break and snack had a 20% chance of being granted parole, compared with 65% for the prisoners appearing right after the break.

“Good decision making is not a trait of the person, in the sense that it’s always there,” according to social psychologist Roy Baumeister who has studied decision fatigue for 20 years. “It’s a state that fluctuates.”

This work raises a number of questions for us ophthalmologists:

-       Are we as good in diagnosis and management (surgical or nonsurgical) with the last patient or two of the day as we are with the first one or two?

-       Should we be sure to take breaks on busy days with challenging patients to gobble a sugary snack or imbibe a sugary drink?

-       Should we read Ophthalmology Times the minute it arrives in our offices or e-mail inbox or wait until we get home at day’s end? (This is a trick question of course. The obvious correct answer is both!)