Microstructural white matter connectivity underlying the attentional networks system.

Nowadays, there is considerable controversy regarding the structural connectivity underlying the attentional networks system (i.e., alerting and vigilance, orienting, and executive control). The present study aimed at further examining and dissociating the white matter connectivity underlying attentional and vigilance functioning by overcoming some critical limitations in previous research. To this end, we performed virtual in vivo dissections of attention-related white matter tracts from thirty healthy adults. Participants completed two sessions of the Attentional Networks Test for Interactions and Vigilance, a suitable task to assess simultaneously phasic alertness, orienting, executive control, and the executive component of vigilance (i.e., the ability to detect infrequent critical signals). Whereas we found a consistent correlation between phasic alertness and both the right dorsolateral prefrontal caudate tract and the splenium of the corpus callosum, evidence obtained for white matter connectivity underlying orienting, executive control, and executive vigilance, was either weak at the best, inconsistent, or null. White matter connectivity seemed to support nevertheless the most reliable performance: overall reaction time for attentional functioning was significantly associated with the left cingulate fasciculus and overall reaction time for executive vigilance was significantly linked to the bilateral superior longitudinal fasciculus I. The present outcomes provide interesting, consistent, and reliable evidence concerning the structural connectivity underlying the alerting network. We still consider that further evidence is necessary to better understand the controversial relationship between attentional/vigilance processes and microstructural white matter connectivity though.