Bradley L. Schlaggar, M.D., Ph.D.

DEPARTMENT OF Neurology
Keywords: development, cognitive, imaging

We use functional MRI (fMRI) to describe differences in patterns of brain activation in normal children and adults performing identical cognitive tasks. These experiments focus on the development of two cognitive domains, language and control. The long-term goal is to characterize a developmental context for studies of children with atypical development either genetic or acquired.

For language development, we study visual and auditory modalities of lexical (single word) processing. Over the past several years we have developed a strategy that allows for the determination of functional neuroanatomical differences between adults and children that are driven by performance discrepancies versus maturation per se. Such an approach generalizes to any group comparison using functional imaging. An important concept derived from this work is that identical behavioral performance can
be supported by non-identical functional neuroanatomy.

Control refers to putative brain processes that serve to link the functions of anatomically distinct cognitive modules. Abnormal control has substantial clinical relevance. Common pediatric neuropsychiatric disorders such as Tourette Syndrome are thought to be due, in part, to dysfunction of control. Efforts in the laboratory currently address the developmental functional neuroanatomy of control through the use of recently developed mixed state/item fMRI designs. Regions performing cognitive functions can be thought to have both sustained and transient activity, reflecting state-and item-related processing, respectively. If control is intimately linked to the establishment of a brain-state, then brain regions serving control may well demonstrate sustained activity during task performance, and show state-related interaction effects on item activity.