Brain imaging and behavior
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Brain Imaging Behav · Dec 2014
ReviewDiffusion tensor imaging and magnetic resonance spectroscopy in traumatic brain injury: a review of recent literature.
Concussion is the most common form of traumatic brain injury (TBI), but diagnosis remains controversial because the brain appears quite normal in conventional computed tomography and magnetic resonance imaging (MRI). These conventional tools are not sensitive enough to detect diffuse traumatic axonal injury, and cannot depict aberrations in mild TBIs. Advanced MRI modalities including diffusion tensor imaging (DTI), and magnetic resonance spectroscopy (MRS), make it possible to detect brain injuries in TBI. ⋯ Our review provides a summary of some of the important studies published from 2002 to 2012 on the topic of MRI findings in head trauma. With the growing realization that even mild head injury can lead to neurocognitive deficits, medical imaging has assumed preeminence for detecting abnormalities associated with TBI. Advanced MRI modalities such as DTI and MRS have an important role in the diagnosis of lesions for TBI patients.
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Brain Imaging Behav · Dec 2014
Effects of acute psychosocial stress on neural activity to emotional and neutral faces in a face recognition memory paradigm.
Previous studies have shown that acute psychosocial stress impairs recognition of declarative memory and that emotional material is especially sensitive to this effect. Animal studies suggest a central role of the amygdala which modulates memory processes in hippocampus, prefrontal cortex and other brain areas. We used functional magnetic resonance imaging (fMRI) to investigate neural correlates of stress-induced modulation of emotional recognition memory in humans. ⋯ BOLD data during recognition revealed a stress condition by emotion interaction in the left inferior frontal gyrus and right hippocampus which was due to a stress-induced increase of neural activity to fearful and a decrease to neutral faces. Functional connectivity analyses revealed a stress-induced increase in coupling between the right amygdala and the right fusiform gyrus, when processing fearful as compared to neutral faces. Our results provide evidence that acute psychosocial stress affects medial temporal and frontal brain areas differentially for neutral and emotional items, with a stress-induced privileged processing of emotional stimuli.