As you know by now, I am a fan of placebos. They often provide significant benefits and with fewer side effects and much lower costs than “real” medication. How can you argue with that? Just because you are deceived in the process . . . .
Because I am an advocate, I need to be careful to note when placebos fall down on the job. For my own benefit, it helps me avoid the self-delusion that I am always going on about. It is OK to self-delude if that delusion magnifies a beneficial placebo effect. But not if it leads me to overestimate the power of the placebo effect in general and get myself into trouble. I am happy to be an advocate, but not an ignorant one. And since I am always telling you about effective placebos, I should be fair and balanced and also tell you when they are not effective.
So I am biting the bullet and sharing with you a paper I just read by a neuroscience team from the University Medical Center in Hamburg, Germany. They used a very small placebo, so that could explain the lack of results, but I thought I should share it anyway.
The influence of positive or negative expectations on clinical outcomes such as pain relief or motor performance in patients and healthy participants has been extensively investigated for years. Such research promises potential benefit for patient treatment by deliberately using expectations as means to stimulate endogenous regulation processes. Especially regarding recent interest and controversies revolving around cognitive enhancement, the question remains whether mere expectancies might also yield enhancing or impairing effects in the cognitive domain, i.e., can we improve or impair cognitive performance simply by creating a strong expectancy in participants about their performance?
They told participants in the study that tones were associated with increased or decreased cognitive performance. This is not true, but the participants didn’t know this. That is the placebo. Then they had the participants complete some simple cognitive tasks. They asked participants how they thought they performed on the task and they measured participants’ actual performance.
The results showed that the placebo had a subjective effect – participants hearing the positive tone placebo thought they did much better, but those hearing neutral or negative tones did not. But the positive tone placebo failed to increase the participants’ objective performance compared to the control condition. The researchers thought it might if the positive prime increased persistence or focus on the task. No dice.
There are a few important limitations of the study. Positive primes increase the level of construal. If the task required a low level of construal, then the positive prime wouldn’t increase performance, even if it was an effective cognitive placebo for other tasks. Also, a tone is a pretty weak placebo. Easy to manipulate in a lab study, but weak.
Placebos can be a sensitive topic because some people don’t believe in deceptive design, even if it is implemented for the benefit of the user’s health, welfare, or performance. So perhaps you are happy to see the approach fail here. Or do you agree with me that white hat placebos are good, just not black hat placebos?
Let us know.
Image Credit: Anthony Kelly