Generalized anxiety modulates frontal and limbic activation in major depression.

Background: Anxiety is relatively common in depression and capable of modifying the severity and course of depression. Yet our understanding of how anxiety modulates frontal and limbic activation in depression is limited.

Methods: We used functional magnetic resonance imaging and two emotional information processing tasks to examine frontal and limbic activation in ten patients with major depression and comorbid with preceding generalized anxiety (MDD/GAD) and ten non-depressed controls.

Two-stage decompositions for the analysis of functional connectivity for fMRI with application to Alzheimer's disease risk.

Functional connectivity is the study of correlations in measured neurophysiological signals. Altered functional connectivity has been shown to be associated with a variety of cognitive and memory impairments and dysfunction, including Alzheimer's disease. In this manuscript we use a two-stage application of the singular value decomposition to obtain data driven population-level measures of functional connectivity in functional magnetic resonance imaging (fMRI).

Differential brain activation in anorexia nervosa to Fat and Thin words during a Stroop task.

We measured brain activation in six anorexia nervosa patients and six healthy controls performing a novel emotional Stroop task using Fat, Thin, and Neutral words, and words made of XXXXs. Reaction times increased in the patient group in Thin and Fat conditions. In the Thin-XXXX contrast, patients showed greater activation than controls at the junction of left insula, frontal and temporal lobes and in left middle and medial frontal gyri.

Effect of handedness on fMRI activation in the medial temporal lobe during an auditory verbal memory task.

Several studies have shown marked differences in the neural localization of language functions in the brains of left-handed individuals when compared with right-handers. Previous experiments involving functional lateralization have demonstrated cerebral blood flow patterns that differ concordantly with subject handedness while performing language-related tasks. The effect of handedness on function in specific stages of memory processing, however, is a largely unexplored area.

Altered fMRI activation during mental rotation in those at genetic risk for Alzheimer disease.

Objective: This study was undertaken to examine differential functional MRI patterns in those at genetic risk for Alzheimer disease (AD), specifically investigating parietal lobe activation, a brain region with changes noted in the early stages of AD.

Methods: This study uses functional MRI to investigate blood oxygenation level dependent changes in the parietal lobe in a high-risk sample of 18 asymptomatic offspring of autopsy-confirmed AD cases, compared to 15 matched controls. The cognitive activation paradigm was a mental rotation task, which requires individuals to rotate three-dimensional cube stimuli to judge their similarity.