Although cognitive systems are critical to the educational and social development of children, few studies have explored the development of neuronal systems subserving cognition. While functional neuroimaging has been a valuable tool for the study of the neural basis of cognition in adults, imaging studies of normal children have historically been limited due to the radiation exposure associated with the techniques. Only recently has functional magnetic resonance imaging (fMRI) emerged as a non-invasive functional imaging tool posing little to no risk to the subject, making it suitable for the study of normal children. In this study, fMRI, in conjunction with a battery of neuropsychological assessments, will be used to investigate the functional neuroanatomical bases of cognitive skill acquisition. Seven-, ten-, and twenty-year-old subjects will be scanned while performing implicit word identification, letter identification, object identification, and visually triggered finger movement tasks. Areas of significant developmental change will be evaluated. Correlations between task-related activity and performance on neuropsychological measures will further delineate the neural correlates of behavior. Conjunction analysis between the age-related changes in the four tasks will be used to assess the relationship between the development of word identification, letter identification, object identification, and basic sensory and motor systems. This work will provide novel insight into the neurophysiological correlates of normal cognitive development, information which is essential to the future investigation of developmental disorders of language and cognition. Previous research suggests that several distributed brain areas represent the mature substrates for these tasks. Developmental changes will likely include shifts from immature areas to these mature systems, increased laterality of activation, and changes in extent of activation. Some developmental changes will be specific to single cognitive tasks while others will represent more general cognitive or sensorimotor maturation.
| Turkeltaub, Peter E; Flowers, D Lynn; Verbalis, Alyssa et al. (2004) The neural basis of hyperlexic reading: an FMRI case study. Neuron 41:11-25 |
