Since 1998, the U.S. has mandated folic acid (FA) fortification of certain grain products to reduce the risk of neural tube defects.
View Article and Find Full Text PDFInstrumental learning is mediated by goal-directed and habit systems in the brain. While rodent studies implicate distinct prefrontal/striatal regions in goal-directed and habit learning, neural systems underpinning these two processes in humans remain poorly understood. Here, using a validated discrimination learning task that distinguishes goal-directed learning from habit learning in 72 subjects in fMRI, we investigated the corticostriatal correlates of goal-directed learning and tested whether brain activation during learning is associated with trait motivation and behavioral performance in the post-learning test phase.
View Article and Find Full Text PDFLocal prefrontal dopamine signaling supports working memory by tuning pyramidal neurons to task-relevant stimuli. Enabled by simultaneous positron emission tomography-magnetic resonance imaging (PET-MRI), we determined whether neuromodulatory effects of dopamine scale to the level of cortical networks and coordinate their interplay during working memory. Among network territories, mean cortical D1 receptor densities differed substantially but were strongly interrelated, suggesting cross-network regulation.
View Article and Find Full Text PDFWorking memory (WM) impairment, a core feature of schizophrenia, is often associated with aberrant dorsolateral prefrontal cortex (dlPFC) activation. Reduced resting-state connectivity within the frontoparietal control network (FPCN) has also been reported in schizophrenia. However, interpretation of WM-related dlPFC dysfunction has been limited by performance differences between patients and controls, and by uncertainty over the relevance of resting-state connectivity to network engagement during task.
View Article and Find Full Text PDFBackground: Psychodynamic psychotherapy has been used to treat depression for more than a century. However, not all patients respond equally well, and there are few reliable predictors of treatment outcome.
Methods: We used resting (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) scans immediately before and after a structured, open trial of brief psychodynamic psychotherapy (n = 16) in conjunction with therapy process ratings and clinical outcome measures to identify neural correlates of treatment response.