In this study, the microstructural organization of each attention tract
was characterized using single diffusion estimates averaged over the
entire tract, which may have obscured our ability to detect additional
group differences between the tracts. Future studies should attempt to
provide more detailed characterization of the microstructural organization
of the tracts associated with attention by looking at localized
differences along the pathways, especially the cingulum bundle.
Newly available tractography software, such as Automatic Fiber Quantification
(AFQ), can be used for this purpose (Yeatman et al., 2012).
In summary,we found that themicrostructural organization of tracts
associated with attention was altered in VPT children compared with
term-born children.We also found that, among VPT children, variations
in the microstructural organization of some of these tracts were associated
with attention outcomes, particularly within the left cingulum
bundle. These findings may indicate that a delay and/or impairment in
the development of these tracts may, at least in part, be responsible
for the attention dysfunction observed in VPT children