Functional MRI studies of the neural mechanisms of human brain attentional networks

Objective To identify the neural mechanisms of the anterior attention network (AAN) and posterior attention network (PAN), investigate the possible interaction between them with event-related functional MRI(ER-fMRI). Methods Eight right-handed healthy volunteers participated in the experiment designed with inhibition of return in visual orienting and Stroop color-word interference effect. The fMRI data were collected on Siemens 1.5 T Sonata MRI systems and analyzed by AFNI to generate the activation map. Results The data sets from 6 of 8 subjects were used in the study.The functional localizations of the Stroop and IOR, which manifest the function of the AAN and PAN respectively, were consistent with previous imaging researches. On cued locations, left inferior parietal lobule(IPL), area MT/V5, right dorsolateral prefrontal cortex (DLPFC) and left anterior cingulated cortex (ACC) were significantly activated. On uncued locations, right superior parietal lobule(SPL)and bilateral area MT/V5 were significantly activated. Conclusion The AAN exerts control over the PAN, while its function can be in turn modulated by the PAN. There are interaction between the AAN and PAN. In addition, it is also proved that ER-fMRI is a feasible method to revise preexisting cognitive model and theory.