Learned control over distraction is disrupted in amnesia.

Recent studies have demonstrated that brief periods of training facilitate the ability to overcome distraction during future performance of a given task, and researchers have proposed that these effects rely on relational memory systems that enable individuals to link specific attentional states to their learned context. In the current work, we examined whether medial temporal lobe (MTL) structures critical for relational and contextual learning contribute to these effects. A group of amnesic patients with bilateral MTL damage and a group of matched comparison subjects both completed an attentional-capture task in which a brief training session typically leads to decreased distraction in a subsequent testing session. Whereas the comparison subjects showed normal training-related decreases in distractibility, the amnesic patients did not. Thus, our results indicate that MTL-mediated learning plays a critical role in the ability to use past experience to overcome distraction. This suggests a tight linkage between MTL-dependent relational-learning mechanisms and cognitive control.