NeuroImage
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This fMRI study was set up to explore how cognitive empathy, i.e. the cognitive inference on another person's affective state, can be characterized as a distinct brain function relating to pre-existing neurofunctional concepts about mentalizing and empathy. In a 3 Tesla MRI scanner 28 healthy participants were presented with four different instructions randomly combined with 32 false-belief cartoon stories of 3 subsequent pictures free of direct cues for affective states, like e.g. facial expressions. Participants were instructed to judge affective or visuospatial changes from their own (1st person perspective) or the protagonists' (3rd person perspective, 3rdpp) perspective. 3rdpp-judgements about affective states differed from visuospatial 3rdpp judgements by a significantly higher activation of the anterior mentalizing network (dorsomedial prefrontal cortex, anterior superior temporal sulcus, temporal poles) and the limbic system (left amygdala and hippocampus). ⋯ The simultaneous activation of the cortical mentalizing network and the amygdala indicates that cognitive empathy actually involves reference to own affective states in the observer. Notably, the cognitive reference to own affective states activated the mentalizing network as well. Moreover our results support pre-existing ideas about a functional anterior-posterior subdivision of the mentalizing network, depending on affective content and 3rd person perspective of cognition.
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Although the exact number of affected individuals is unknown, it has been estimated that approximately 20% of U. S. veterans of Operations Enduring Freedom (OEF) and Iraqi Freedom (OIF) have experienced mild traumatic brain injury (mTBI) (i.e., concussion), which is defined as a brief loss or alteration of consciousness from a blow or jolt to the head. Blast exposure is among the most common causes of concussion in OEF-OIF warriors. ⋯ MDD relative to non-MDD individuals showed greater activity during fear matching trials in the amygdala and other emotion processing structures, lower activity during fear matching trials in emotional control structures such as the dorsolateral prefrontal cortex and lower fractional anisotropy (FA) in several white matter tracts including the superior longitudinal fasciculus (SLF). Greater depressive symptom severity correlated negatively with FA in the SLF. These results suggest a biological basis of MDD in OEF-OIF veterans who have experienced blast-related concussion, and may contribute to the development of treatments aimed at improving the clinical care of this unique population of wounded warriors.
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Research in blast-induced lung injury resulted in exposure thresholds that are useful in understanding and protecting humans from such injury. Because traumatic brain injury (TBI) due to blast exposure has become a prominent medical and military problem, similar thresholds should be identified that can put available research results in context and guide future research toward protecting war fighters as well as diagnosis and treatment. At least three mechanical mechanisms by which the blast wave may result in brain injury have been proposed-a thoracic mechanism, head acceleration, and direct cranial transmission. ⋯ There is a subset of blast conditions likely to result in TBI due to head acceleration and/or a thoracic mechanism without concomitant lung injury. These results can be used to guide experimental designs and compare additional data as they become available. Additional data are needed before actual probabilities or severity of TBI for a given exposure can be described.
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The objective of the study was to examine whether deep brain stimulation (DBS) of the subthalamic nucleus (STN), the globus pallidus internus (GPi), and/or the ventralis intermedius thalamic nucleus (Vim) was associated with making patients angrier pre to post-surgical intervention. ⋯ STN and GPi DBS for Parkinson's disease were associated with significantly higher anger scores pre- to post-DBS as compared to Vim for essential tremor. Anger score changes in STN and GPi patients seem to be associated with microelectrode passes, suggesting that it may be a lesional effect. PD patients with longer disease duration may be particularly susceptible, and this should be kept in mind when discussing the potential of DBS surgery for an individual patient. Essential tremor patients who on average have much longer disease durations did not get angrier. The changes in anger scores were not related to LED change or dopamine agonist use. Whether the induction of anger is disease-specific or target-specific is not currently known; however, our data would suggest that PD patients implanted in STN or GPi are at a potential risk. Finally, on closer inspection of the COMPARE DBS data, VAMS anger scores did not change on or off DBS, suggesting that anger changes may be more of a lesional effect rather than a stimulation induced one (Okun et al., 2009).
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The aim of this study was to compare the relative effectiveness of 6 different commonly used language fMRI activation paradigms, including receptive and expressive, as well as semantic and phonological tasks, for hemispheric lateralization in brain tumor patients utilizing both threshold-dependent and threshold-independent approaches. We studied 46 right-handed patients with primary intra-axial brain tumors with BOLD fMRI on a 3-T MRI system. A linear fit of the laterality indices (LIs) as a function of the t-value (which varied from 2.0 to 6.5) was calculated and the slope (M) taken as measure of LI variability in the threshold-dependent LI approach; for the threshold-independent approach, the LIs were determined by comparing the integrated T-score weighted distributions of all positively task-correlated voxels of the left and the right hemispheric regions of interest. ⋯ Furthermore, R (mean LI value=61.91, M=7.9±1.5) had a higher mean LI value and was less threshold-dependent than SWG (mean LI=52.97, M=11.40±0.64) for LI determination. SWG and R were able to provide effective language lateralization even in the subgroup of patients with lesions located in the left hemisphere and in the frontal or parietal lobes. The receptive language paradigms examined in this study (passive listening [PL], listening comprehension [LC], and reading comprehension [RC]) were less effective than SWG and R for language lateralization.