This study included 32 UHR subjects and 32 age- and gender-matched healthy controls (HCs). The Barratt Impulsiveness Scale version-11 (BIS-11) was employed to assess impulsivity. Differences between the groups in gray matter volume in the anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (DLPFC), and orbitofrontal cortex (OFC) were assessed. Then, a correlational analysis between the BIS-11 scores and significant clusters of gray matter volume was conducted in UHR subjects.
UHR subjects were more impulsive than HC subjects in terms of attention (t = 3.5187, p < 0.01), motor (t = 3.1751, p < 0.01), and non-planning (t = 4.4154, p < 0.01) scores. The gray matter volume of the ACC was negatively correlated with the motor (r = ? 0.472, p < 0.01) and non-planning (r = ? 0.354, p = 0.04) scores of the BIS-11 in UHR subjects.
These results suggest that impulsivity in UHR subjects may reflect altered integrated conflict processing, which likely stems from abnormalities in the ACC, rather than altered reward/punishment processing or executive control.