Effects of attention and emotion on face processing in the human brain: Anevent-related fMRI study

We used event-related fMRI to assess whether brain responses to fearful ver sus neutral faces are modulated by spatial attention. Subjects performed a demanding matching task for pairs of stimuli at prespecified locations, in the presence of task-irrelevant stimuli at other locations. Faces or houses unpredictably appeared at the relevant or irrelevant locations, while the faces had either fearful or neutral expressions. Activation of fusiform gyr i by faces was strongly affected by attentional condition, but the left amy gdala response to fearful faces was not. Right fusiform activity was greate r for fearful than neutral faces, independently of the attention effect on this region. These results reveal differential influences on face processin g from attention and emotion, with the amygdala response to threat-related expressions unaffected by a manipulation of attention that strongly modulat es the fusiform response to faces.