Background: The pattern of structural brain abnormalities in anorexia nervosa (AN) is still not well understood. While several studies report substantial deficits in gray matter volume and cortical thickness in acutely underweight patients, others find no differences, or even increases in patients compared with healthy control subjects. Recent weight regain before scanning may explain some of this heterogeneity.
View Article and Find Full Text PDFBackground: Anorexia nervosa (AN) is a disorder characterized by an incapacitating fear of weight gain and by a disturbance in the way the body is experienced, facets that motivate dangerous weight loss behaviors. Multimodal neuroimaging studies highlight atypical neural activity in brain networks involved in interoceptive awareness and reward processing.
Methods: The current study used resting-state neuroimaging to model the architecture of large-scale functional brain networks and characterize network properties of individual brain regions to clinical measures.
Background: Transdiagnostic clinical emotional dysregulation is a key component of many mental health disorders and offers an avenue to address multiple disorders with one transdiagnostic treatment. In the current study, we pilot an intervention that combines a one-time teaching and practice of cognitive restructuring (CR) with repetitive transcranial magnetic stimulation (rTMS), targeted based on functional magnetic resonance imaging (fMRI).
Methods: Thirty-seven clinical adults who self-reported high emotional dysregulation were enrolled in this randomized, double-blind, placebo-controlled trial.
Pandemic health threats can cause considerable anxiety, but not all individuals react similarly. To understand the sources of this variability, we applied a theoretical model developed during the H1N1 pandemic of 2009 to quantify relationships among intolerance of uncertainty, stress appraisals, and coping style that predict anxiety about the COVID-19 pandemic. We surveyed 1579 U.
View Article and Find Full Text PDFCogn Affect Behav Neurosci
October 2020
Extinction learning is a primary means by which conditioned associations to threats are controlled and is a model system for emotion dysregulation in anxiety disorders. Recent work has called for new approaches to track extinction-related changes in conditioned stimulus (CS) representations. We applied a multivariate analysis to previously -collected functional magnetic resonance imaging data on extinction learning, in which healthy young adult participants (N = 43; 21 males, 22 females) encountered dynamic snake and spider CSs while passively navigating 3D virtual environments.
View Article and Find Full Text PDFPhysical proximity to a traumatic event increases the severity of accompanying stress symptoms, an effect that is reminiscent of evolutionarily configured fear responses based on threat imminence. Despite being widely adopted as a model system for stress and anxiety disorders, fear-conditioning research has not yet characterized how threat proximity impacts the mechanisms of fear acquisition and extinction in the human brain. We used three-dimensional (3D) virtual reality technology to manipulate the egocentric distance of conspecific threats while healthy adult participants navigated virtual worlds during functional magnetic resonance imaging (fMRI).
View Article and Find Full Text PDFDistancing is an effective tactic for emotion regulation, which can take several forms depending on the type(s) of psychological distance being manipulated to modify affect. We recently proposed a neurocognitive model of emotional distancing, but it is unknown how its specific forms are instantiated in the brain. Here, we presented healthy young adults (N = 34) with aversive pictures during functional magnetic resonance imaging to directly compare behavioral performance and brain activity across spatial, temporal, and objective forms of distancing.
View Article and Find Full Text PDFPurpose: To describe the initial neuroradiology findings in a cohort of military service members with primarily chronic mild traumatic brain injury (TBI) from blast by using an integrated magnetic resonance (MR) imaging protocol.
Materials And Methods: This study was approved by the Walter Reed National Military Medical Center institutional review board and is compliant with HIPAA guidelines. All participants were military service members or dependents recruited between August 2009 and August 2014.
Introduction: Understanding clinical reasoning is essential for patient care and medical education. Dual-processing theory suggests that nonanalytic reasoning is an essential aspect of expertise; however, assessing nonanalytic reasoning is challenging because it is believed to occur on the subconscious level. This assumption makes concurrent verbal protocols less reliable assessment tools.
View Article and Find Full Text PDFA definitive diagnosis of mild traumatic brain injury (mTBI) is difficult due to the absence of biomarkers in standard clinical imaging. The brain is a complex network of interconnected neurons and subtle changes can modulate key networks of cognitive function. The resting state default mode network (DMN) has been shown to be sensitive to changes induced by pathology.
View Article and Find Full Text PDFBackground: Studies of resident fatigue and performance have shown mixed results. However, research has not examined daytime sleepiness and performance among attending physicians. The purpose of this study was to explore the relationship between sleep, performance and prefrontal cortex (PFC) activity.
View Article and Find Full Text PDFTraumatic brain injury (TBI) is a common combat injury, often through explosive blast, and produces heterogeneous brain changes due to various mechanisms of injury. It is unclear whether the vulnerability of white matter differs between blast and impact injury, and the consequences of microstructural changes on neuropsychological function are poorly understood in military TBI patients. Diffusion tensor imaging (DTI) techniques were used to assess the neurocircuitry in 37 U.
View Article and Find Full Text PDFBackground: Whether the think-aloud protocol is a valid measure of thinking remains uncertain. Therefore, we used functional magnetic resonance imaging (fMRI) to investigate potential functional neuroanatomic differences between thinking (answering multiple-choice questions in real time) versus thinking aloud (on review of items).
Methods: Board-certified internal medicine physicians underwent formal think-aloud training.
This review focuses on the application of functional magnetic resonance imaging (fMRI) to the investigation of blast-related traumatic brain injury (bTBI). Relatively little is known about the exact mechanisms of neurophysiological injury and pathological and functional sequelae of bTBI. Furthermore, in mild bTBI, standard anatomical imaging techniques (MRI and computed tomography) generally fail to show focal lesions and most of the symptoms present as subjective clinical functional deficits.
View Article and Find Full Text PDFPerfusion deficits in patients with mild traumatic brain injury (TBI) from a military population were characterized by dynamic susceptibility contrast perfusion imaging. Relative cerebral blood flow (rCBF) was calculated by a model-independent deconvolution approach from the tracer concentration curves following a bolus injection of gadolinium diethylenetriaminepentaacetate (Gd-DTPA) using both manually and automatically selected arterial input functions (AIFs). Linear regression analysis of the mean values of rCBF from selected regions of interest showed a very good agreement between the two approaches, with a regression coefficient of R = 0.
View Article and Find Full Text PDFAnnu Int Conf IEEE Eng Med Biol Soc
July 2013
A major challenge associated with understanding mild traumatic brain injury (mTBI) is the absence of biomarkers in standard clinical imaging modalities. Furthermore, the inhomogeneity of mTBI location and intensity, combined with latent symptoms further complicates identification and treatment. A growing body of evidence suggests that the thalamus may be injured or susceptible to change as the result of mTBI.
View Article and Find Full Text PDFBackground: Clinical reasoning is essential to medical practice, but because it entails internal mental processes, it is difficult to assess. Functional magnetic resonance imaging (fMRI) and think-aloud protocols may improve understanding of clinical reasoning as these methods can more directly assess these processes. The objective of our study was to use a combination of fMRI and think-aloud procedures to examine fMRI correlates of a leading theoretical model in clinical reasoning based on experimental findings to date: analytic (i.
View Article and Find Full Text PDFAny tracer in fetal tissue comes from maternal arterial blood. Provided steady state is achieved and intermediate compartments are reversible, the Logan graphical methods should be applicable to the assessment of binding parameters in the fetal brain. Two pregnant rhesus macaques were studied with fallypride and the Logan method was used to assess dopamine receptor distribution volume ratios (DVRs) in both maternal and fetal striatum.
View Article and Find Full Text PDFUntil recently, little was known regarding the famous "Three Mayos" photograph. New findings are herein described, which demonstrate that this photograph was taken by Dr. Harvey Cushing in 1905 at the site of Dr.
View Article and Find Full Text PDFStanton K. Livingston was the country's foremost authority on the maggot therapy of war wounds in the years following World War I. His contributions to the literature, including his methodology for raising flies and applying their maggots, are discussed.
View Article and Find Full Text PDFIn the Rare Books Room of the Mayo Clinic Library is a book, Sir Thomas Browne's Religio Medici, which may contain the earliest extant book inscription penned by Sir William Osler. Dr. John Graner reports that Osler gave the book to one of his closest friends when he attended McGill medical school in 1870.
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