| Literature DB >> 12507945 |
Ed Bullmore1, John Suckling, Fernando Zelaya, Chris Long, Garry Honey, Laurence Reed, Carol Routledge, Virginia Ng, Paul Fletcher, John Brown, Steve C R Williams.
Abstract
Brain activation is adaptive to task difficulty and practice. We used functional MRI to map brain systems activated by an object-location learning task in 24 healthy elderly volunteers each scanned following placebo and two of four active drugs studied. We distinguished a fronto-striatal system adaptive to difficulty from a posterior system adaptive to practice. Fronto-striatal response to increased cognitive load was significantly attenuated by scopolamine, sulpiride and methylphenidate; practice effects were not modulated by these drugs but were enhanced by diazepam. We also found enhancement by methylphenidate, and attenuation by sulpiride, of load response in premotor, cingulate and parietal regions comprising a spatial attention network. Difficulty and practice evoke anatomically and pharmacologically dissociable brain activation dynamics, which are probably mediated by different neurotransmitter systems in humans.Entities:
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Year: 2003 PMID： 12507945 PMCID： PMC3838949 DOI： 10.1093/cercor/13.2.144
Source DB: PubMed Journal: Cereb Cortex ISSN： 1047-3211 Impact factor: 5.357