A gateway system in rostral PFC? Evidence from biasing attention to perceptual information and internal representations.

Some situations require us to be highly sensitive to information in the environment, whereas in other situations, our attention is mainly focused on internally represented information. It has been hypothesized that a control system located in the rostral prefrontal cortex (PFC) acts as gateway between these two forms of attention. Here, we examined the neural underpinnings of this 'gateway system' using fMRI and functional connectivity analysis. We designed different tasks, in which the demands for attending to external or internal information were manipulated, and tested 1) whether there is a functional specialization within the rostral PFC along a medial-lateral dimension, and 2) whether these subregions can influence attentional weighting processes by specifically interacting with other parts of the brain. Our results show that lateral aspects of the rostral PFC are preferentially activated when attention is directed to internal representations, whereas anterior medial aspects are activated when attention is directed to sensory events. Furthermore, the rostrolateral subregion was preferentially connected to regions in the prefrontal and parietal cortex during internal attending, whereas the rostromedial subregion was connected to the basal ganglia, thalamus, and sensory association cortices during external attending. Finally, both subregions interacted with another important prefrontal region involved in cognitive control, the inferior frontal junction, in a task-specific manner, depending on the current attentional demands. These findings suggest that the rostrolateral and rostromedial part of the anterior PFC have dissociable roles in attentional control, and that they might, as part of larger networks, be involved in dynamically adjusting the contribution of internal and external information to current cognition.