Ricciardi, Emiliano and Handjaras, Giacomo and Bernardi, Giulio and Pietrini, Pietro and Furey, Maura L. Cholinergic enhancement reduces functional connectivity and BOLD variability in visual extrastriate cortex during selective attention. Neuropharmacology, 64. 305 - 313. ISSN 0028-3908 (2013)
Full text not available from this repository.Abstract
Enhancing cholinergic function improves performance on various cognitive tasks and alters neural responses in task specific brain regions. We have hypothesized that the changes in neural activity observed during increased cholinergic function reflect an increase in neural efficiency that leads to improved task performance. The current study tested this hypothesis by assessing neural efficiency based on cholinergically-mediated effects on regional brain connectivity and BOLD signal variability. Nine subjects participated in a double-blind, placebo-controlled crossover fMRI study. Following an infusion of physostigmine (1 mg/h) or placebo, echo-planar imaging (EPI) was conducted as participants performed a selective attention task. During the task, two images comprised of superimposed pictures of faces and houses were presented. Subjects were instructed periodically to shift their attention from one stimulus component to the other and to perform a matching task using hand held response buttons. A control condition included phase-scrambled images of superimposed faces and houses that were presented in the same temporal and spatial manner as the attention task; participants were instructed to perform a matching task. Cholinergic enhancement improved performance during the selective attention task, with no change during the control task. Functional connectivity analyses showed that the strength of connectivity between ventral visual processing areas and task-related occipital, parietal and prefrontal regions reduced significantly during cholinergic enhancement, exclusively during the selective attention task. Physostigmine administration also reduced BOLD signal temporal variability relative to placebo throughout temporal and occipital visual processing areas, again during the selective attention task only. Together with the observed behavioral improvement, the decreases in connectivity strength throughout task-relevant regions and {BOLD} variability within stimulus processing regions support the hypothesis that cholinergic augmentation results in enhanced neural efficiency. This article is part of a Special Issue entitled ‘Cognitive Enhancers’.
| Item Type: | Article |
|---|---|
| Identification Number: | 10.1016/j.neuropharm.2012.07.003 |
| Uncontrolled Keywords: | Functional magnetic resonance imaging |
| Subjects: | R Medicine > RC Internal medicine > RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry |
| Research Area: | Computer Science and Applications |
| Depositing User: | Users 72 not found. |
| Date Deposited: | 10 Nov 2015 12:03 |
| Last Modified: | 13 Sep 2016 09:48 |
| URI: | http://eprints.imtlucca.it/id/eprint/2874 |
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