"Also, the three types of distracters gave us good controls, which allowed us to clearly establish that the observed effects were due to the presence of emotional distraction rather than to the presence of other meaningful (neutral images) or meaningless (scrambled images) distracters."
The researchers also found individual differences among the subjects in their response to the images. Those people who showed greater activity in a brain region associated with the inhibition of response to emotional stimuli rated the emotional distracters as less distracting. Said Dolcos, "One interpretation of this finding is that, because this region is associated with inhibitory process, people who engage that region more could cope better with distracting emotions."
McCarthy said that the results of their study will likely have important implications for understanding of anxiety disorders. "Our hypothesis has been that people suffering from such anxiety disorders such as depression and PTSD, may see the world differently than other people, and that a distracter associated with trauma may grab control of brain processing and essentially take off-line those areas of the brain we use to stay on task. It's as if when you're sad, the world seems sadder and all you see is bad news."
"Our aim is to reverse that with drug treatment, so we're using these kinds of studies to determine whether particular antidepressants influence the response of that ventral system. And what is particularly exciting is that this method allows us to look directly at the neurological target of the drug and not have to try to measure the more nebulous behavioral response. So, we can detect a sub-threshold response to such drugs, which will help us understand whether we're going in the right direction in terms of drug develop
Contact: Dennis Meredith
Duke University Medical Center