In this particular study, the kids were put in the fMRI machine and then were read stories. What the researchers found was that children who were read to more at home showed more brain activation in the areas of the brain thought to be responsible for narrative processing and imagery. Basically, it looked like kids who were read to more were processing the story more effectively. How this links to later reading is unclear, and the study was small (fMRI scans are really expensive to run). Nevertheless, it provides some further evidence on the mechanisms that might drive effects.
