V Calhoun

..e., increased in spatial extent) at the higher dose. Alcohol, thus, appears to have both global and local effects upon the neural correlates of the MVPT-R task, some of which are dose dependent...

..We show that combining data types can improve our ability to distinguish differences between groups...

..The use of prior time course information in a spatial ICA analysis, which combines elements of both a regression approach and a blind ICA approach, may prove to be a useful tool for fMRI analysis...

..The proposed method may prove to be useful in answering questions requiring multigroup comparisons when a flexible modeling approach is desired...

..controls, suggesting that more gray matter may be related to less functional connectivity in the auditory oddball fMRI task...

..The fMRI data also suggest that the deficits observed in alcohol intoxication may be modulated primarily through OF/anterior cingulate, motor and cerebellar regions as opposed to attentional areas in frontoparietal cortex...

..The proposed test is applied in a random-effects analysis of 100 subjects. It reveals increased amplitudes in areas consistent with the task, with the largest increases in regions with greater hemodynamic delays...

..In both studies we found specific circuits that were differentially modulated by alcohol, we revealed both global and local effects of alcohol, and we examined relationships between behavior, brain function, and alcohol blood levels...

..It thus provides a way to integrate and probe brain networks using a variety of tasks and may increase our understanding of coordinated brain networks and the impact of pathology upon them...

..The resulting time courses, the component maps, and the latency maps may prove useful as an addition to the collection of methods for fMRI data analysis...

..We show that fusing imaging modalities with different advantages can provide new information about the brain...

..An influential theory is that FTD results from impaired semantic memory processing. We explored the neural correlates of semantic memory retrieval in schizophrenia using an imaging task assessing semantic object recall...

..Overall, results suggest that alcohol (especially at high doses) causes significant impairment of both driving behavior and brain functionality related to motor planning and control, goal directedness, error monitoring, and memory...

..The variable striatal activity in the Huntington's group suggests early functional loss possibly associated with previously demonstrated early atrophy of these same neural structures...

..Numerous neuroimaging studies report abnormal regional brain activity during working memory performance in schizophrenia, but few have examined brain network integration as determined by "functional connectivity" analyses...

..We identify and characterize several age-related differences in the function of neural circuits that are associated with behavioral performance changes across adolescent development...

..It was hypothesized that the default mode network would show abnormal activation and connectivity in patients with schizophrenia...

..Additionally, differences between encoding and retrieval suggest that WM dysfunction may be manifested differently during the distinct phases of encoding, maintenance, and retrieval...

..These findings characterize the spatial structure of neural networks underlying error commission and identify neurobiological differences between adolescents and adults...

....

..Significant differences between patient and control connectivity in different networks were revealed possibly reflecting deficiencies in cortical processing in patients...

..Previous functional MRI (fMRI) studies of the VO task have shown activation in the anterior cingulate, hippocampus, and prefrontal cortex. Thus, we predicted dose-dependent decreases in activation of these areas during VO performance...

....

..These findings are discussed within the context of current biological and information processing models of neural timekeeping...

..In summary, TCNs show considerable promise as potential imaging biological markers of brain diseases, though each network needs to be studied in more detail...

..Simultaneous measure of anatomical and functional connectivity and its interactions allow for better understanding of schizophrenia-related alternations in brain connectivity...

..A combination of two such hemodynamic brain networks shows promise as a biomarker for schizophrenia and bipolar disorder...

..This process may be termed 'adaptive reflexive processing.' The implications of these results for interpreting functional MRI studies are discussed...

..Our experimental results show that the source density-driven ICA method can improve performance further by incorporating some a priori information into ICA analysis of fMRI signals...

..The combination of both techniques presented here allows for further combining them to provide richer representation of brain connectivity both in the healthy brain and in clinical conditions...

..Additionally, fMRI differences in both conditions were modulated by load, with a parametric increase in between-group differences with load in several key regions during encoding and an opposite effect during response selection...

..However, results from these studies vary widely, likely due to different methodological or statistical approaches...

..However, the functional connectivity between these circuits has not yet been explored in order to determine how these networks communicate with each other during sober and alcohol-intoxicated states...

..There was no such effect of novel interval, suggesting that neuronal modulation may only occur for task-relevant stimuli, possibly in the service of strategic resource allocation processes...

..GLM analysis elucidated several comparable regions, with the exception of the hippocampus. Inefficient allocentric learning and memory in patients may be related to an inability to recruit appropriate task-dependent neural circuits...

..This technique, designed to have increased sensitivity to inter-subject correlations that are not necessarily task-related, may potentially be useful as a compliment to model-based approaches...

..Although VBM is rapid and fully automated, it is not a replacement for manual ROI-based analyses. Both methods provide different types of information and should thus be used in tandem...

..Additional components and significant findings are further outlined. CONCLUSION: In summary, continuous behavioral variables conjoined with ICA may offer new insight into the neural correlates of complex human behavior...

..The results of this study support the physiogenomic analysis of neuroimaging data to discover associations between genotype and disease-related phenotypes...

..These results contribute to an emerging understanding that activity in widely distributed networks thought to underlie complex cognition influences activity in other networks...

..Understanding the circuit that normally mediates this process is relevant for schizophrenia, where many regions in this circuit are functionally abnormal and semantic memory is impaired...

..The results (1) support the proposal that the right hemisphere is differentially engaged in processing salient stimuli and (2) demonstrate the successful use of a new voxel-based laterality analysis technique for fMRI data...

..A reliable technique for discriminating schizophrenia based upon fMRI would be a significant advance and may also provide additional information about the biological implications of mental illness...

..The need to control for sex effects is not critical in the analysis of this task with fMRI...

....

..05), with the exception of old and young age groups in RO region (P = 0.11). CONCLUSION: The group analysis, and unpaired t test results reveal higher amplitude of fMRI activation in the young versus the old and middle-aged groups...

..The effect of anticipation should be minimized, which could best be achieved by using event-related paradigms...

..The onset of activation showed no direct correlation with the overall RTs of the subjects, leading one to suggest that the peripheral motor unit may have a greater impact on RT than the central contribution...

..There was a negative correlation between RTs and activation volume in the left sensorimotor cortex (P =.048). CONCLUSION: There was a greater activation volume in motor and visual cortices in the fast RT group than in the slow RT group...

..The findings suggest that the proposed data reduction algorithm is effective in classifying individuals into schizophrenia and healthy control groups and may eventually prove useful as a diagnostic tool...

..Our results greatly improve our confidence in the consistency of ICA for fMRI data analysis...

..We illustrate the utility of this method by extracting a previously undetected but relevant EEG-fMRI component from a concurrent auditory target detection experiment...

..Our results indicate that this approach is a feasible and physiologically plausible data-driven way to achieve spatiotemporal mapping of event related responses in the human brain...

..Increases in cerebellar and occipital areas, presumably related to complex visuomotor integration, are activated during driving but not associated with driving speed...

..These data may also provide functional evidence of the interaction between neocortical and medial temporal lobe pathology in early AD...

....

..Our findings provide insights into the brain network dynamics preceding human performance errors and suggest that monitoring of the identified precursor states may help in avoiding human errors in critical real-world situations...

..We interpret our finding as a proof of principle, demonstrating that functional brain disorders can be characterized by functional-disconnectivity profiles of RSNs...

..Thus, the amplitude of activation can be used as one parameter to assess change in function...