Resting state functional connectivity reveals intrinsic, spontaneous networks that elucidate the functional architecture of the human brain. However, valid statistical analysis used to identify such networks must address sources of noise in order to avoid possible confounds such as spurious correlations based on non-neuronal sources. We have developed a functional connectivity toolbox Conn (www.nitrc.org/projects/conn) that implements the component-based noise correction method (CompCor) strategy for physiological and other noise source reduction, additional removal of movement, and temporal covariates, temporal filtering and windowing of the residual blood oxygen level-dependent (BOLD) contrast signal, first-level estimation of multiple standard functional connectivity magnetic resonance imaging (fcMRI) measures, and second-level random-effect analysis for resting state as well as task-related data. Compared to methods that rely on global signal regression, the CompCor noise reduction method all...

Conn: A Functional Connectivity Toolbox for Correlated and Anticorrelated Brain Networks

Diagnostic and Statistical Manual of Mental Disorders, 4th ed

Frontocingulate Dysfunction in Depression: Toward Biomarkers of Treatment Response

Individuals with anorexia nervosa have a relentless preoccupation with dieting and weight loss that results in severe emaciation and sometimes death. It is controversial whether such symptoms are secondary to psychosocial influences, are a consequence of obsessions and anxiety or reflect a primary disturbance of brain appetitive circuits. New brain imaging technology provides insights into ventral and dorsal neural circuit dysfunction — perhaps related to altered serotonin and dopamine metabolism — that contributes to the puzzling symptoms found in people with eating disorders. For example, altered insula activity could explain interoceptive dysfunction, and altered striatal activity might shed light on altered reward modulation in people with anorexia nervosa.

New insights into symptoms and neurocircuit function of anorexia nervosa

Neurobiology of anorexia and bulimia nervosa.

Objective: Individuals with anorexia nervosa are known to be ascetic and able to sustain self-denial of food as well as most comforts and pleasures in life. Building on previous findings of altered striatal dopamine binding in anorexia nervosa, the authors sought to assess the response of the anterior ventral striatum to reward and loss in this disorder. Method: Striatal responses to a simple monetary reward task were investigated using event-related functional magnetic resonance imaging. To avoid the confounding effects of malnutrition, the authors compared 13 healthy comparison women and 13 women who had recovered from restricting-type anorexia nervosa and had 1 year of normal weight and regular menstrual cycles, without binge eating or purging. Results: Recovered women showed greater hemodynamic activation in the caudate than comparison women. Only the recovered women showed a significant positive relationship between trait anxiety and the percentage change in hemodynamic signal in the caudate during e...

https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.2007.07040575

Altered Reward Processing in Women Recovered From Anorexia Nervosa

http://eatingdisorders.ucsd.edu/research/pub/imaging/doc/2008/wagner2008altered.pdf

Altered Insula Response to Taste Stimuli in Individuals Recovered from Restricting-Type Anorexia Nervosa

Objective: To characterize the functional neuroanatomy of late-life depression (LLD) by probing for both episodic and persistent alterations in the executive-control circuit of elderly adults. Design: Event-related functional magnetic resonance imaging (fMRI) data were collected while participants performed an executive-control task. Setting: Participants were recruited through a depression-treatment study within the Pittsburgh, PA, Intervention Research Center for Late-Life Mood Disorders. Participants: Thirteen nondepressed elderly comparison participants and 13 LLD patients. Intervention: The depressed patients underwent imaging before initiating and after completing 12 weeks of paroxetine. Measurements: Regional fMRI activity was assessed in the dorsolateral prefrontal cortex (dLPFC: BA9 and BA46 bilaterally) and the dorsal anterior cingulate cortex (dACC). Functional connectivity was assessed by correlating the fMRI time-series in the dLPFC and dACC. Results: Both depressed and comparison participants performed the task as expected, with greater response latency during high versus low-load trials. The response-latency load-effect did not differ between groups. In contrast to the null findings for behavioral data, pretreatment, depressed patients showed diminished activity in the dLPFC (BA46 left, t(25) = 1.9, p=0.035) and diminished functional connectivity between the dLPFC and dACC. Moreover, right dLPFC (BA46 right, t (25) = 2.17, p Conclusions: These results support a model of both episodic and persistent neurobiologic components of LLD. The altered functional connectivity, perhaps due to vascular damage to frontal white matter, appears to be persistent. Further, at least some of the prefrontal hypoactivity (in the right dLPFC) seems to be an episodic characteristic of acute depression amenable to treatment.

/pdf/altered-functioning-of-the-executive-control-circuit-in-late-3m9l6g7f70.pdf

Laura Mazurkewicz

Papers

Altered Reward Processing in Women Recovered From Anorexia Nervosa

Altered Insula Response to Taste Stimuli in Individuals Recovered from Restricting-Type Anorexia Nervosa

Altered functioning of the executive control circuit in late-life depression: episodic and persistent phenomena.