Cortical activation during sequences of memory-guided saccades: a functional MRI study

Blood oxygenation-level dependent changes in the cerebral cortex were measured using event-related functional magnetic resonance imaging in participants while they performed triple-step memory-guided saccades. To explore the role of dorsolateral prefrontal cortex in the manipulation of the contents of working memory, the sequence of saccade targets in the memory-guided task was either constant or was manipulated using coloured cues. The dorsolateral prefrontal cortex was significantly activated only during the period when participants had to reorder the locations of the saccade targets and not during the maintenance of spatial locations. This finding suggests that dorsolateral prefrontal cortex is primarily involved in the manipulation, and to a lesser extent, in the maintenance of the contents of working memory.