Brain activity linking negative emotions to a lower immune response against disease has been revealed for the first time, claim researchers. Many previous studies have shown that emotions and stress can adversely affect the immune system. But this effect had not been directly correlated with activity in the brain, says study leader Richard Davidson, at the University of Wisconsin, Madison, in the US. The part of the brain the team studied, the prefrontal cortex (PFC), is associated with depression. People who had the greatest activity in the right PFC when asked to dwell on distressing episodes in their life had a markedly lower antibody levels after an influenza vaccination. In contrast, those showing exceptional activity in the left PFC when recalling happy times developed high antibody levels. NewScientist