Uncertainty can make a bad event feel even worse. Researchers at the University of Wisconsin-Madison showed 36 student volunteers a mixture of neutral and distressing images. Before each image was presented the students were shown three symbols: a circle to indicate an image would be neutral, a cross to indicated that it would be unpleasant and a question mark to denote uncertainty. At the same time brain scans measured the levels of activity in two areas of the brain important for emotional responses, the amygdala and the insula. The study found that the insula and amygdala responded more strongly to the distressing picture if it was preceeded by a question mark (uncertainty) than if it was preceeded by a cross (certainty).
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