Women with bulimia may be more impulsive than other women, according to research carried out at Columbia University in the U.S. The researchers used a task called the Simon Spatial Incompatibility Task to measure impulsiveness. In the task an arrow appears on a computer screen and participants have to decide in which direction it is pointing. The arrow can appear in any place on the screen, so, for instance, an arrow could appear on the right-hand side of the screen but pointing left. The idea behind the test is that more impulsive people will reach a decision based on the arrow's position rather than the direction in which it is pointing and therefore get more wrong answers. The study compared 20 women with bulimia to 20 controls and the participants also undertook a brain scan while they took the tests. The women with bulimia did less well on the task and showed less activity in an area of the brain called the frontostriatal circuits which help individuals control their voluntary behaviour.
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