Abstract
Higher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010) to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets. This design allowed comparing a condition in which participants monitored one stimulus/modality (either visual or auditory) in two spatial locations vs. a condition in which participants monitored two stimuli/modalities (both visual and auditory) in one spatial location. The analysis of the independent components (ICs) revealed that dividing attentional resources across two spatial locations necessitated a brain network involving the left ventro- and dorso-lateral prefrontal cortex plus the posterior parietal cortex, including the intraparietal sulcus (IPS) and the angular gyrus, bilaterally. The analysis of Granger causality highlighted that the activity of lateral prefrontal regions were predictive of the activity of all of the posteriors parietal nodes. By contrast, dividing attention across two sensory modalities necessitated a brain network including nodes belonging to the dorsal frontoparietal network, i.e., the bilateral frontal eye-fields (FEF) and IPS, plus nodes belonging to the salience network, i.e., the anterior cingulated cortex and the left and right anterior insular cortex (aIC). The analysis of Granger causality highlights a tight interdependence between the dorsal frontoparietal and salience nodes in trials requiring divided attention between different sensory modalities. The current findings therefore highlighted a dissociation among brain networks implicated during divided attention across spatial locations and sensory modalities, pointing out the importance of investigating effective connectivity of large-scale brain networks supporting complex behavior.
Highlights
It is well established that higher-order cognitive processes rely on the interplay between large-scale neural networks (Bressler and Menon, 2010; Raichle, 2015; Wig, 2017)
Divided Attention across Spatial Locations: ICA and Granger Causality Analysis (GCA) Trials requiring dividing attention across the two hemifields involved the selective contribution of independent components (ICs) 8, as revealed by the analysis of beta weights that contrasted ‘‘att2mod > att2mod’’
Consistent with standard fMRI analyses reported by the previous literature (Fagioli and Macaluso, 2009, 2016; Santangelo et al, 2010; Santangelo and Macaluso, 2013a), the current study found that divided attention was sustained by regions belonging to the frontal and parietal cortices
Summary
It is well established that higher-order cognitive processes rely on the interplay between large-scale neural networks (Bressler and Menon, 2010; Raichle, 2015; Wig, 2017). How such multiple networks interact to support a complex cognitive process such as divided attention is largely unknown. Previous research has demonstrated that monitoring of multiple streams of information typically results in a decrement of processing efficacy At a neurophysiological level, divided attention was shown to recruit high-level brain regions, such as the dorsal frontoparietal attention network (Fagioli and Macaluso, 2009, 2016; Santangelo et al, 2010), showing modulatory effects on sensory cortices deputed to process the incoming, multiple information (McMains and Somers, 2004, 2005; Sreenivasan et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
