Psychiatry - Research Publications

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Author: Harrison, Benjamin × End date: 2019 × Start date: 2012 × Subject: functional connectivity ×

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    Breakdown in the brain network subserving moral judgment in criminal psychopathy
    Pujol, J ; Batalla, I ; Contreras-Rodriguez, O ; Harrison, BJ ; Pera, V ; Hernandez-Ribas, R ; Real, E ; Bosa, L ; Soriano-Mas, C ; Deus, J ; Lopez-Sola, M ; Pifarre, J ; Menchon, JM ; Cardoner, N (OXFORD UNIV PRESS, 2012-11)
    Neuroimaging research has demonstrated the involvement of a well-defined brain network in the mediation of moral judgment in normal population, and has suggested the inappropriate network use in criminal psychopathy. We used functional magnetic resonance imaging (fMRI) to prove that alterations in the brain network subserving moral judgment in criminal psychopaths are not limited to the inadequate network use during moral judgment, but that a primary network breakdown would exist with dysfunctional alterations outside moral dilemma situations. A total of 22 criminal psychopathic men and 22 control subjects were assessed and fMRI maps were generated to identify (i) brain response to moral dilemmas, (ii) task-induced deactivation of the network during a conventional cognitive task and (iii) the strength of functional connectivity within the network during resting-state. The obtained functional brain maps indeed confirmed that the network subserving moral judgment is underactive in psychopathic individuals during moral dilemma situations, but the data also provided evidence of a baseline network alteration outside moral contexts with a functional disconnection between emotional and cognitive elements that jointly construct moral judgment. The finding may have significant social implications if considering psychopathic behavior to be a result of a primary breakdown in basic brain systems.
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    Functional Connectivity in Brain Networks Underlying Cognitive Control in Chronic Cannabis Users
    Harding, IH ; Solowij, N ; Harrison, BJ ; Takag, M ; Lorenzetti, V ; Lubman, DI ; Seal, ML ; Pantelis, C ; Yuecel, M (NATURE PUBLISHING GROUP, 2012-07)
    The long-term effect of regular cannabis use on brain function underlying cognitive control remains equivocal. Cognitive control abilities are thought to have a major role in everyday functioning, and their dysfunction has been implicated in the maintenance of maladaptive drug-taking patterns. In this study, the Multi-Source Interference Task was employed alongside functional magnetic resonance imaging and psychophysiological interaction methods to investigate functional interactions between brain regions underlying cognitive control. Current cannabis users with a history of greater than 10 years of daily or near-daily cannabis smoking (n=21) were compared with age, gender, and IQ-matched non-using controls (n=21). No differences in behavioral performance or magnitude of task-related brain activations were evident between the groups. However, greater connectivity between the prefrontal cortex and the occipitoparietal cortex was evident in cannabis users, as compared with controls, as cognitive control demands increased. The magnitude of this connectivity was positively associated with age of onset and lifetime exposure to cannabis. These findings suggest that brain regions responsible for coordinating behavioral control have an increased influence on the direction and switching of attention in cannabis users, and that these changes may have a compensatory role in mitigating cannabis-related impairments in cognitive control or perceptual processes.