Abstract
Our ability to overcome distraction by salient but irrelevant information in the environment relies critically on the acquisition and implementation of effective attentional control settings. It is often hypothesized that these settings are implemented on-line in an effortful, controlled manner, but recent evidence suggests that such settings can be implemented automatically, with past experience being a major determinant of the settings used in a given task context (e.g., Leber & Egeth, 2006a). This suggests that observers store information about the control settings used in a particular task context for later use, allowing these learned settings to be implemented rapidly and automatically when encountering similar tasks in the future. Such an interpretation would necessarily implicate long-term memory processes, and to this end the current study examined the role of the medial temporal lobes, known to be involved in long-term contextual learning, in the acquisition and implementation of such context-specific control settings. A group of patients with severe amnesia due to bilateral medial temporal lobe damage, in addition to neurologically normal and brain-damaged comparison subjects, were trained to use one of two strategies to complete a basic attentional capture task, and were then tested on a similar task in which multiple strategies were available (a la Leber & Egeth, 2006a). Although there was a robust carryover effect in both neurologically normal and brain-damage comparison participants, no carryover effect was observed in any of the amnesic patients, suggesting that medial temporal lobe structures are integral to generating context-specific control settings. This result demonstrates a novel role for the medial temporal lobes and long-term contextual memory in the control of visual attention and argues that task experience is a critical factor in determining the extent of attentional capture.