Eyes

As I note in Chapter 1, "When subjected to scrutiny, crazy-sounding ideas sometimes find support." Thus, an experiment not only exposes many falsehoods, but it also surprises us sometimes by jarring our preconceived ideas. Before the experiments were done, who would have expected that removing half a young child's cortex would have such a minimally devastating effect, that sharing the same parental rearing would have so little influence on a child's personality, or that shocking the brain into convulsions would be therapeutic for severely depressed people?

A fresh demonstration of how scientific inquiry can challenge its own presumptions, as well as to deflate pseudo-science, comes from Scott Campbell and Patricia Murphy of the Cornell University Medical College Department of Psychiatry. Perhaps you have read press reports of their experiment showing that the human biological clock appears to be manipulated by light administered to (and I am not making this up) the back of the knee. No, this wasn't published in the National Enquirer or a Rupert Murdoch tabloid, but rather in the 16 January 1998 Science. Subjects, who were blind to their treatment condition, received light through a covered knee pad for different three-hour periods from midnight to noon--or received no light at all. Two nights later, those treated with light found their body's dip in temperature shifted by up to three hours. Those getting sham treatment experienced no significant changes in body rhythms. (Article available online at www.sciencemag.org/content/current/ with subscription; abstract available with free registration).

We've known for some time that bright light taken in by the eyes helps adjust circadian rhythms (see the Sleep and Dreams section). Exposure to bright light is therefore an antidote for jet lag, shift work-related insomnia, and seasonal depression (for more information on seasonal depression and how light therapy can help, go to http://www.sada.org.uk/). But eyes in the back of our knees? Well, not eyes, say the researchers, but maybe blood vessels that allow light to reach sensitive blood cells, such as hemoglobin.

Obviously, replication is needed before we start dreaming of treating winter depression with light to the skin or jet-setters awakening refreshed in Europe after sleeping with light on the back of the knees. But there is a heartening lesson about science here--one that goes deeper than the press stories about light and circadian rhythm. Postmodernists sometimes chide us psychological scientists with the reminder that science is value laden. Our preconceived ideas--our schemas--guide our theory development, our interpretations, our topics-of-choice, and our language. In questing for truth, we follow our hunches, our biases, our voices within. Findings we are predisposed to believe, we welcome. Those that don't fit our schemas, we resist.

True enough. For scientists, as for everyone else, belief guides perception. Yet, as this report illustrates, nature can surprise us. When beliefs collide with observation, beliefs do sometimes change. Scientists initially scoffed at the notion that meteorites had extraterrestrial origins. (When two Yale scientists suggested otherwise, Thomas Jefferson responded, "I would rather believe that those two Yankee Professors would lie than to believe that stones fell from heaven.") Later ideas about nerve cells communicating via chemical messengers, about cosmic black holes, about ethereal subatomic particles were all similarly mind-blowing--until the evidence overwhelmed our doubts.

And so it is in psychological science. There was a time, not so very long ago, when many of us believed that sleepwalkers were acting out their dreams; that newborns were perceptually incompetent; that hypnosis or brain stimulation could uncover precise but long-buried memories; that electroconvulsive therapy was a barbaric and ineffective therapy for intractable depression; that sexual orientation was bred by a domineering mother and effeminate father; that opposites attract; that their shared parental nurture shapes siblings in common ways. But put to the test, these and other cherished ideas have suffered the fate of Mount St. Helen's. As Agatha Christie's Miss Marple explained, "It wasn't what I expected. But facts are facts, and if one is proved to be wrong, one must just be humble about it and start again."

Of course, more often than not, when crazy-sounding ideas are put to the test, they self-destruct. Sometimes, however, nature dishes up a surprise. That is one reason why studying psychology is endlessly fascinating.