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Various studies have investigated reproducibility of fMRI results. Whereas group results can be highly reproducible, individual activity maps tend to vary across sessions. Individual reliability is of importance for the application of fMRI in endophenotype research, where brain activity is linked to genetic polymorphisms. In this study, the test-retest(More)
The default-mode network (DMN) consists of areas showing more activation during rest than during a task. Several authors propose some form of cognitive processing to underlie BOLD signal changes in the DMN as activity within the network is modulated by the level of effort required by the task and is positively correlated with self-referential processing.(More)
BACKGROUND Obsessive-compulsive disorder (OCD) is primarily conceived as an anxiety disorder but has features resembling addictive behavior. Patients with OCD may develop dependency upon compulsive behaviors because of the rewarding effects following reduction of obsession-induced anxiety. Reward processing is critically dependent on ventral(More)
The ability to stop a prepared response (reactive inhibition) appears to depend on the degree to which stopping is expected (proactive inhibition). Functional MRI studies have shown that activation during proactive and reactive inhibition overlaps, suggesting that the whole neural network for reactive inhibition becomes already activated in anticipation of(More)
We used functional magnetic resonance imaging (fMRI) to study the role of the striatum in inhibitory motor control. Subjects had to refrain from responding to designated items (STOP trials) within a similar series of motor stimuli. Striatal activation was increased significantly compared to that when responding to all targets within a series of motor(More)
Almost all cortical areas are connected to the subcortical basal ganglia (BG) through parallel recurrent inhibitory and excitatory loops, exerting volitional control over automatic behavior. As this model is largely based on non-human primate research, we used high resolution functional MRI and diffusion tensor imaging (DTI) to investigate the functional(More)
Little is known about the underlying neural mechanism of deep brain stimulation (DBS). We found that DBS targeted at the nucleus accumbens (NAc) normalized NAc activity, reduced excessive connectivity between the NAc and prefrontal cortex, and decreased frontal low-frequency oscillations during symptom provocation in patients with obsessive-compulsive(More)
Stopping an action requires suppression of the primary motor cortex (M1). Inhibitory control over M1 relies on a network including the right inferior frontal cortex (rIFC) and the supplementary motor complex (SMC), but how these regions interact to exert inhibitory control over M1 is unknown. Specifically, the hierarchical position of the rIFC and SMC with(More)
Abnormalities in the frontal lobe are considered to be central to the pathology of schizophrenia. Neuroimaging studies indeed report abnormal function of the frontal lobe in schizophrenia patients. However, the nature of these functional abnormalities is unclear, in particular whether they are affected by medication. We therefore investigated whether(More)