FRIDAY, Oct. 12, 2001 (HealthDayNews) -- If you're feeling more stressed these days and are having trouble concentrating, it may be that your attention is "stuck."
A new study may help explain why people can't get the images and impact of the Sept. 11 terrorist attacks off their minds. Led by British psychologist Elaine Fox, researchers at the University of Essex report that in times of anxiety, the human brain tends to dwell on threatening stimuli.
For several years, scientists who study mental processes have suspected that anxious people process threatening information quicker than neutral or positive information. "The idea [was] that there's a genuine bias in attention, so that an anxious person will notice threats much more quickly in their environment than a non-anxious person," says Fox.
But her own theory differed slightly. She suspected that anxious people not only notice threats quicker but tend to dwell on them longer. "They can't move away from that information as easily as others," she says.
Her findings will be published in the December issue of the Journal of Experimental Psychology: General. She created a series of five experiments involving 282 students and staff members between the ages of 17 and 60 at the University of Essex. All the participants filled out questionnaires that helped separate them into groups of either low or high anxiety.
In one experiment, says Fox, the participants focused on a random happy, neutral or angry face in the center of a computer screen, and had to notice whether they saw one of two letters appear for 50 milliseconds above or below the face.
"The anxious people took longer to categorize the letter when the face was angry, compared to when it was neutral or happy," says Fox. "Whereas for non-anxious people, there was no difference in reaction time across the three different types of face."
However, the participants were not at all aware that their response times slipped in response to a potential threat.
The researchers are now turning their attention to why certain people might have this lag time due to anxiety.
"We know that there are certain parts of the brain that become far more active than others when threatening faces, for example, are presented," says Fox. "Virtually no work has been done looking specifically at anxiety in relation to this, but one of the possibilities is that anxious people actually have a much more sensitive fear-detection system in the brain."
"But we know generally that a key feature of clinical anxiety is worry and rumination," she adds. Dwelling on threats may be a vicious cycle, she says, because "this may lead to more anxiety."
Fox hopes to look in greater detail at whether this effect on attention may ultimately influence how anxious people tend to worry and ruminate over things.
Richard McNally, a professor of psychology at Harvard University in Cambridge, Mass., says that Fox's study advances research on attention bias and anxiety. "It's an important step forward in our understanding of how cognition and emotion interact," he says.
"It shows that the key issue here is not so much that attention is drawn to threatening stimuli, but rather that once threatening stimuli attract attention, people who are anxiety-prone have a difficult time disengaging attention," says McNally. Threatening stimuli tend to stick in their minds, he adds.
Fox's study suggests that, in evolutionary terms, it doesn't seem to make sense that we would dwell on a potential threat to the point of slowing our reaction time to other stimuli or blocking them out entirely. "On the other hand, you could say that it may well be important to process exactly the nature of the threat," says Fox, since it would provide humans with more detail with which to develop coping mechanisms, such as flight or fight.
The data in this study couldn't give Fox a clear sense of how quickly the brain should normalize after perceiving a threat in this anxious state. And although this research was done long before Sept. 11, she says that the findings may shed light on how many Americans are feeling in the wake of the terrorist attacks.
"Obviously, something as threatening as the World Trade Center coming down is likely to have a huge impact on everyone," says Fox. "As the threat [becomes worse], it may well be a much more general effect."
She says that although she would expect a clinically anxious person to respond more severely, events of this magnitude could explain why many Americans feel drawn to watch the images on television and are reporting difficulty concentrating and shifting their attention back to the normal routine of their life.
McNally agrees that this may be a factor in the state of mental distraction that some Americans describe. "She may have indeed isolated the same type of mechanisms that have been amplified to such a distressing extent in the recent weeks."
Fox adds that the ongoing retaliatory strikes in Afghanistan could prolong the anxiety. "It's generally a fairly threatening time when people aren't really quite sure what's going to happen next," says Fox. "In terms of clinical anxiety, I think that would cause quite a lot of problems for people."
What To Do
The American Red Cross Web site provides counseling materials to help you and your family deal with the trauma of the events of September 11. The Federal Emergency Management Agency has also published resources for those dealing with the aftermath of the terrorist attacks.
The National Institute of Mental Health provides information on anxiety disorders and phobias.