Advanced neuroimaging of mild traumatic brain injury.

This article focuses on advancements in neuroimaging techniques, compares the advantages of each of the modalities in the evaluation of mild traumatic brain injury, and discusses their contribution to our understanding of the pathophysiology as it relates to prognosis. Advanced neuroimaging techniques discussed include anatomic/structural imaging techniques, such as diffusion tensor imaging and susceptibility-weighted imaging, and functional imaging techniques, such as functional magnetic resonance imaging, perfusion-weighted imaging, magnetic resonance spectroscopy, and positron emission tomography.

Component structure of individual differences in true and false recognition of faces.

Principal-component analyses of 4 face-recognition studies uncovered 2 independent components. The first component was strongly related to false-alarm errors with new faces as well as to facial "conjunctions" that recombine features of previously studied faces. The second component was strongly related to hits as well as to the conjunction/new difference in false-alarm errors. The pattern of loadings on both components was impressively invariant across the experiments, which differed in age range of participants, stimulus set, list length, facial orientation, and the presence versus absence of familiarized lures along with conjunction and entirely new lures in the recognition test. Taken together, the findings show that neither component was exclusively related to discrimination, criterion, configural processing, featural processing, context recollection, or familiarity. Rather, the data are consistent with a neuropsychological model that distinguishes frontal and occipitotemporal contributions to face recognition memory. Within the framework of the model, findings showed that frontal and occipitotemporal contributions are discernible from the pattern of individual differences in behavioral performance among healthy young adults.