One of the hallmarks of cognitive control is the suppression of prepotent but inappropriate responses. Here we used event-related functional MRI to measure functional brain activation during a stimulus-response incompatibility task. Subjects were instructed before a stimulus appeared either to look at the stimulus (prosaccade) or to look away from the stimulus (antisaccade). Eye movements were recorded so that functional brain activation could be grouped into prosaccades, correct antisaccades, and errors (saccades toward the stimulus on antisaccade trials). Correct antisaccade trials were associated with significantly more activation in frontal and parietal cortical areas compared with prosaccade trials during the late preparatory period before stimulus appearance. Correct antisaccades evoked more activation than errors in the right dorsolateral prefrontal cortex, anterior cingulate cortex (ACC), and presupplementary eye fields during this period. No significant differences were found for any comparisons early in the preparatory period. Our data suggest that the preparation of an antisaccade activates a large frontal and parietal network that may be involved in presetting the oculomotor system for the antisaccade task. These findings indicate that a large network of frontal and posterior areas is modulated during the latter component of the preparatory period on antisaccade compared with prosaccade trials. The results further suggest that the activation level of frontal cortical areas before stimulus presentation is associated with subjects' performance in the antisaccade task. In contrast, we found no areas that were more active for correct antisaccades than prosaccades or for correct antisaccades than error antisaccades during the stimulus-response period. In fact, a number of posterior cortical areas and a few areas in the superior frontal lobe were more active during the stimulus-response period on prosaccade trials than on antisaccade trials. Error antisaccades showed a larger activation in the ACC during the stimulus-response period compared with correct antisaccades.

Several current models hold that frontoparietal areas exert cognitive control by biasing task-relevant processing in other brain areas. Previous event-related functional magnetic resonance imaging (fMRI) studies have compared prosaccades and antisaccades, which require subjects to look toward or away from a flashed peripheral stimulus, respectively. These studies found greater activation for antisaccades in frontal and parietal regions at the ends of long (>or=6 s) preparatory periods preceding peripheral stimulus presentation. Event-related fMRI studies using short preparatory periods (

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Neuroimaging-based diagnostics could potentially assist clinicians to make more accurate diagnoses resulting in faster, more effective treatment. We participated in the 2011 ADHD-200 Global Competition which involved analyzing a large dataset of 973 participants including Attention deficit hyperactivity disorder (ADHD) patients and healthy controls. Each participant's data included a resting state functional magnetic resonance imaging (fMRI) scan as well as personal characteristic and diagnostic data. The goal was to learn a machine learning classifier that used a participant's resting state fMRI scan to diagnose (classify) that individual into one of three categories: healthy control, ADHD combined (ADHD-C) type, or ADHD inattentive (ADHD-I) type. We used participants' personal characteristic data (site of data collection, age, gender, handedness, performance IQ, verbal IQ, and full scale IQ), without any fMRI data, as input to a logistic classifier to generate diagnostic predictions. Surprisingly, this approach achieved the highest diagnostic accuracy (62.52%) as well as the highest score (124 of 195) of any of the 21 teams participating in the competition. These results demonstrate the importance of accounting for differences in age, gender, and other personal characteristics in imaging diagnostics research. We discuss further implications of these results for fMRI-based diagnosis as well as fMRI-based clinical research. We also document our tests with a variety of imaging-based diagnostic methods, none of which performed as well as the logistic classifier using only personal characteristic data.

The Fort McMurray wildfire was the costliest disaster in Canadian history, with far-reaching impacts. The purpose of this paper is to examine the prevalence and risk factors of elevated generalized anxiety disorder (GAD) symptomatology in residents of Fort McMurray 6 months after the wildfire. Data were collected via random selection procedures from 486 participants. Generalized anxiety disorder symptoms were measured via the GAD-7. The 1-month prevalence rate for GAD symptomatology 6 months after the disaster was 19.8% overall, regression analyses revealed six variables with significant unique contributions to prediction of GAD symptomatology. Significant predictors were: pre-existing anxiety disorder, witnessing of homes being destroyed by the wildfire, living in a different home after the wildfire, receiving limited governmental support or limited family support, and receiving counseling after the wildfire. Participants with these risk factors were between two to nearly seven times more likely to present with GAD symptomatology. In addition, participants who presented with elevated symptomatology were more likely to increase use or problematically use substances post-disaster. This study extends the literature on mental health conditions and risk factors following disasters, specifically in the area of generalized anxiety. Findings and implications are discussed.