A Developmental fMRI Study of Prefrontal Organization

A developmental functional MRI study of spatial working memory

Functional magnetic resonance imaging (fMRI) was used to examine patterns of cortical activity in children during performance of a spatial working memory task. Six children (8-10 years) and six adults (19-26 years) searched a linear array of four boxes for the appearance of a dot. In the visual blocks, participants made no response. In the motor blocks, participants were instructed to indicate the location of the dot on each trial using a button-press response. In the working memory blocks, participants were instructed to indicate at which location the dot had appeared 1 or 2 trials previously. Both children and adults showed activity in the left precentral and postcentral gyri, as well as the right cerebellum for the motor condition as compared to the visual condition. Comparison of the memory and motor conditions revealed reliable activity in the right superior frontal gyrus (BA 8), right dorsolateral prefrontal cortex (BA 10/46), right superior parietal cortex, and bilateral inferior parietal cortex for both adults and children. These results suggest that spatial working memory tasks activate very similar cortical regions for school-age children and adults. The findings differ from previous imaging studies of nonspatial working memory tasks in that the prefrontal activations observed in the current work tend to be more dorsal. Results are discussed in light of the significant behavioral performance differences observed between child and adult participants.

Functional magnetic resonance imaging in children

Functional magnetic resonance imaging (fMRI) allows for the noninvasive mapping of the anatomical location of disparate functional brain activities. The means for carrying out fMRI involves the use of existing MR technology coupled with a special software image acquisition program or the use of a specially designed head coil. Thus far in pediatric neurology, fMRI has assisted in the presurgical localization of critical functions and the investigation of various developmental activities. The technique of fMRI, its applications in pediatric neuroscience, and future potential are outlined in this article.