Hemispheric organization of visual memories

This study investigates the hemispheric organization of visual memories. In five experiments, we examine the processes associated with the recognition of line patterns that are flashed laterally during a study phase. The first three experiments demonstrate a recognition advantage for patterns presented at test in the same (rather than in the opposite) hemifield in which they were presented during a previous study phase. This difference was obtained even when stimuli were presented in different locations within the same hemifield. Experiment 4 shows that patterns presented centrally during the recognition phase elicit ERPs that are systematically more negative over the hemisphere contralateral to the side at which they were presented during the study phase. In Experiment 5, however, we found that subjects were unable to indicate the side of initial presentation of the patterns. The results suggest that the memory traces left by laterally presented stimuli are more easily accessible in the contralateral hemisphere, which suggests a contralateral organization of visual memories.