Although elementary cognitive processes are in place by early childhood, the capacity for abstract thought, planning, and cognitive flexibility continue to develop throughout adolescence. Similarly, although basic brain structure is adult-like by childhood important brain maturation occurs during this age period including synaptic pruning and myelination. This is a particularly important age period, recognized as the time of onset of serious neuropsychiatric disorders such as mood and substance abuse disorders. Unfortunately, very little is known of the processes underlying the transition into higher-order cognitive capabilities.
The interest of this laboratory lies in characterizing the changes that occur in brain function that subserve the maturation of cognition by bridging developmental psychology and neuroscience. Our current work focuses on delineating the systems-level pattern of brain activation subserving voluntary response suppression and spatial working memory. Currently, our studies use eye movement paradigms that have been well-delineated at the single-cell level in the non-human primate. We use both quantitative eye movement measures in the laboratory and perform neuroimaging studies using fMRI. One of our aims is to establish a template of normal development from which to assess abnormal function in neuropsychiatric disorders. Hence, we are also involved in studies characterizing the functional neuroanatomy of high-functioning autistic individuals.
Our recent findings have revealed that performance in oculomotor tasks requiring voluntary response suppression and spatial working memory shows a significant developmental improvement throughout adolescence. The fMRI studies have demonstrated that during these cognitive eye movement tasks activation in neocortical regions is present in childhood and increase in extent with age. Moreover, more distal regions known to subserve more precise regulation of behavior, like the cerebellum, are only activated in the adult brain. These findings suggest that different stages of cognitive development may be subserved by distinct patterns of brain function and that proficient use of spatial working memory and voluntary response suppression require efficient circuit-level brain organization, possibly subserved by synaptic pruning and myelination that continues into late adolescence. Our recent studies on autistic individuals have revealed that while patients access the basic oculomotor system as healthy controls do to perform cognitive oculomotor tasks, they do not seem to rely on neocortical regions used by healthy individuals known to subserve higher-order cognition.