Advancing Our Understanding of Attention
Post by Megan McCullough
The takeaway
Maps of brain networks involved in attention in humans, generated from functional connectivity analysis, show that subcortical brain structures are essential to both the dorsal attention network and the ventral attention network. This furthers our understanding of the neural correlates of attention, as previous research has mostly focused on the role of the cortex in attention.
What's the science?
Attention — the cognitive task that involves the selection of relevant information for processing — is marked by two distinct attentional networks, the dorsal attention network (DAN) and the ventral attention network (VAN). The DAN is involved in the top-down voluntary orientation to stimuli while the VAN is involved when attention is involuntarily oriented to stimuli. Previous research has focused on these regions in the context of the cortex, but recent electrical recording research, behavioral observations, and animal research have shown the crucial role of subcortical structures in the neural workings of attention. This week in Communications Biology, Alves and colleagues examined the subcortical anatomy of attention networks by aligning functional maps of the DAN and VAN.
How did they do it?
Functional maps of attention networks were drawn from fMRI (functional magnetic resonance imaging) datasets from the Human Connectome Project. The authors utilized resting-state functional analyses to map the subcortical involvement of the DAN and VAN. This technique involves the use of fMRI while the participants are resting in the MRI scanner to generate maps that show the subcortical structures involved in each of the networks. These connectivity maps were then overlayed to examine which subcortical structures were relevant to both networks. The authors then spatially correlated the identified projections with known maps of expression of different receptors and transporters within the brain. This co-mapping of functional and structural data with neurochemical data was done to understand the neural correlates of attention more deeply.
What did they find?
The authors found that subcortical structures such as the pulvinar, superior colliculi, the head of the caudate nucleus, and a group of brainstem nuclei are involved with both attention networks. When the neurochemical data was examined, the authors found that projections in the brainstem nuclei were correlated spatially with acetylcholine nicotinic receptors, serotonin receptors, and dopamine receptors. This builds on previous research that has linked nicotinic receptors with attention. The authors also found that VAN and DAN structural connectivity maps were specific to the right side of the brain.
What's the impact?
This study found that subcortical structures and connectivity are essential in attentional processes. This research builds on previous work that has mostly focused on attention in the context of the cortex. With a stronger model of the VAN and DAN, further research can expand on attention both across species and across brain pathologies.