Electrocution: Placebos and Nocebos

Electrocution is no laughing matter, but I have to chuckle every time I look at the picture on my page that lists the human body's response to various levels of electrical current. The table shows that perceptible pain begins at around 10 mA and death can occur at 100 mA, which came to mind while reading an article in the July/August edition of Discover magazine titled "Why N0thing Works." Author Erik Vance reports on research being done on the effects of placebos (Latin for "I shall please") and nocebos ("I shall harm" - never heard that word before) in healing and pain suppression. Typically we think of placebos as medicinal remedies, but there are other types like the visual stimulus used in an electrical shock / pain experiment to which Mr. Vance subjected himself.

He placed his hand on a device that would administer an electrical shock at random levels, but before applying the juice, a colored screen was flashed on a computer screen to suggest what the level of charge could be expected. Green was a low level shock, yellow mild, and red would illicit fear in anticipation of what would come seconds later. Three rounds of 18 shocks were endured. Vance was relieved when it was over. The results amazed him.

While reviewing the test with Vance, neurologist Luana Colloca, designer of the experiment, showed that for the first two tests, 'strong' shock levels were as high as 101 mA - enough to kill him if it had passed through his heart! Fortunately, the current only flowed between fingers. The difference in current between shocks that ranged in painfulness from mild to strong was a mere 40 mA (roughly 60-100 mA). Here is the surprising part: In the third test, every shock "was fired at full blast," yet the ones preceded by a green screen caused a perceived pain level equal to that of the previous tests' green screens. Evidently, Vance's brain had been sufficiently conditioned in the first two honest tests to respond as trained in the third.

The true test of ruggedness for this type of placebo effect, of course, would be to administer shocks between left and right hands to route current through the heart and see whether it (the heart) can be trained to ignore the potentially lethal current levels. Any volunteers... in the name of science?

Posted November 5, 2014