Differential associations between large-scale networks during externally and internally directed attention
Julia W. Y. Kam1, Sandon Griffin1, Jack J. Lin2, Anne-Kristin Solbakk3, Tor Endestad3, Pal G. Larsson4, Robert T. Knight1; 1University of California, Berkeley, 2University of California, Irvine, 3University of Oslo, 4Oslo University Hospital
Our capacity to flexibly shift between internally and externally directed processes is crucial for successful performance in our daily life. While recent neuroimaging evidence has implicated the fronto-parietal control network in both internally directed processes, including autobiographical memory retrieval and future planning, and externally directed processes, including cognitive control and selective attention, the underlying neural mechanism is still largely unknown. To address this issue, we recorded intracranial EEG activity in patients undergoing presurgical monitoring for intractable epilepsy who were implanted with subdural and/or depth electrodes. Patients performed an attention task wherein half the time, they had to detect target tones (i.e. external condition); the other half of the time, they were instructed to think about whatever comes to mind and ignore all the tones (i.e. internal condition). We correlated low frequency activity (theta: 4-8Hz, alpha: 8-14Hz, beta: 14-30Hz) between electrode pairs across networks (i.e. target detection network, default mode network, and fronto-parietal control network), which were then examined as a function of condition across patients. We found increased correlation between the default mode network and fronto-parietal control network during the internal relative to external conditions, and increased correlation between the task detection network and frontoparietal control network during the external relative to internal conditions. These results indicate that the enhanced spatiotemporal integration of information between the relevant network and the fronto-parietal control network is one potential mechanism in facilitating both externally and internally directed attention.
Topic Area: EXECUTIVE PROCESSES: Goal maintenance & switching