Relational Memory Revealed by Eye Movements: Manipulation Effects and the Role of Awareness

Abstract

Eye movements are an integral part of visual information processing and permit us to align objects of interest with the high-resolution fovea for the acquisition of detailed information. Changes in eye movement behavior have been reported in studies exploring the effects of general knowledge on scene processing, and in studies that have examined memory for arbitrary relationships between objects or for object locations in scenes. Some evidence suggests that relational memory-based viewing effects occur even without corresponding awareness of the remembered content. These findings, however, have not always been replicated, which means that there is not consensus about whether awareness is a requirement for the expression of eye-movement-based relational memory effects. The objective of this investigation was to use memory-sensitive eye movement measures to elucidate the role of awareness in memory-based viewing by specifically examining the influence of testing instruction and manipulation type (i.e., objects added to versus removed from scenes). Results showed that recognition of scene changes was better when objects were added to scenes, and that greater viewing was directed toward objects than toward empty space within a scene. Critically, results revealed that when memory was tested indirectly, and the changed region was now-filled (i.e., an object was added), there was a trend for unaware memory-based viewing effects. These findings indicate that manipulation type and testing instructions are important factors that should be considered separately in studies that are designed to examine unaware memory-based viewing effects.