Patients with bipolar disorder have cognitive problems that persist even after mood regulation. Strakowski et al. (p. 1697) compared brain activation in stable bipolar patients and healthy subjects during a counting task involving cognitive interference. A screen displayed the word "one," "two," "three," or "four" or multiple instances of the same word. In the control condition the number of instances matched the word, and in the interference condition it was discordant with the word. Each person was asked to press the button representing the number of words shown. The healthy subjects slowed down when presented with discordant words, but their responses were more accurate than those of the bipolar patients, who did not slow down. The two groups had similar activation in the brain regions usually associated with interference tasks, but the bipolar patients showed differences in several regions involved in error detection, response inhibition, and conflict resolution. These differences may reflect the underlying dysfunction of bipolar mood disorder.F1