There's no news like bad news. The tabloids are full of accidents, gory murders, and mayhem, and people eat it up. But there may be a silver lining, at least for seniors. A new study finds that the human brain reacts less strongly to emotionally negative stimuli as we age, in effect making us more responsive to all things positive and less responsive to the dark and dismal. This bolsters a growing body of evidence showing that aging changes how the brain reacts to emotional stimuli.
Much of the media exploits what psychologists call the "negativity bias": our tendency to pay more attention to the bad than to the good. This bias plays a role in a wide range of cognitive areas, making a headline about a murder more attention grabbing than one about a marriage, for example. However, in recent years, research has revealed that as we get older our emotional responses to the world around us become more positive and that the stereotype of the "grumpy old man" may actually be a myth. A number of studies have found that older people typically report a higher sense of well-being than younger people. But is that because the negativity bias declines with age, or does the brain become more responsive to positive stimuli?
To explore this question, psychologists Michael Kisley of the University of Colorado, Colorado Springs, and Stacey Wood of Scripps College in Claremont, California, presented 51 participants with images of puppies, car crashes, toasters, and other things for 1 second at a time. The participants, who ranged from 18 to 81 years of age, were attached to electroencephalograph electrodes and then pressed buttons to categorize the images as emotionally positive, negative, or neutral. As expected, electrical activity spiked in the brains of the young participants when they saw something discomfiting. But older brains reacted less, and they didn't vary between negative and positive images. "Our data show that the negativity bias is gradually declining with age," comments Kisley, who reports the findings in the September issue of Psychological Science.
"This study is so important because it gives us a window into the way we process information at different stages of our lives," says psychologist Derek Isaacowitz of Brandeis University in Waltham, Massachusetts. Why the negativity bias wanes with age is an unresolved question, but psychologist Mara Mather of the University of California, Santa Cruz, argues that "it might be the result of a human desire to surround ourselves with the pleasant and the positive as our perceived lifetime draws to a close."