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Abstract:
Abstract: Cognitive and brain maturational changes continue
throughout late childhood and adolescence. Our previous studies
indicate that an age-related trend towards more integrative
widely-distributed brain function subserves the development of
voluntary response suppression. To characterize changes in brain
function underlying the maturation of spatial working memory, we
compared activation during an oculomotor delayed response task
versus a reflexive oculomotor task. Healthy 8 to 30 year-old
subjects were studied using echo-planar whole brain functional
magnetic resonance imaging (fMRI) in a 3T magnet. Results indicated
that the basic system subserving spatial working memory, including
frontal and temporal areas are functional by childhood. Children
activated additional areas known to subserve difficult cognitive
tasks in adults including left dorsolateral prefrontal cortex and
pre-supplementary motor area. They also demonstrate activity in
precuneus and striatum, known to be involved in transformation of
spatial information. By adolescence, modality-specific areas emerge
that are known to subserve motor planning, including the frontal,
supplementary and parietal eye fields. Adults recruit areas known
to subserve motor execution and skilled learning, including the
cingulate motor zone and lateral cerebellum. Taken together, these
results indicate that proficient use of spatial working memory
requires efficient circuit-level brain organization that allows for
the emergence of higher-order cognition. Supported by NARSAD,
NS35949, HD35469, MH42969, & MH45156.
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