| 1. |
- Benedict, Christian, et al.
(författare)
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Acute Sleep Deprivation Enhances the Brain's Response to Hedonic Food Stimuli : An fMRI Study
- 2012
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 97:3, s. E443-447
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Tidskriftsartikel (refereegranskat)abstract
- Context:There is growing recognition that a large number of individuals living in Western society are chronically sleep deprived. Sleep deprivation is associated with an increase in food consumption and appetite. However, the brain regions that are most susceptible to sleep deprivation-induced changes when processing food stimuli are unknown.Objective:Our objective was to examine brain activation after sleep and sleep deprivation in response to images of food.Intervention:Twelve normal-weight male subjects were examined on two sessions in a counterbalanced fashion: after one night of total sleep deprivation and one night of sleep. On the morning after either total sleep deprivation or sleep, neural activation was measured by functional magnetic resonance imaging in a block design alternating between high- and low-calorie food items. Hunger ratings and morning fasting plasma glucose concentrations were assessed before the scan, as were appetite ratings in response to food images after the scan.Main Outcome Measures:Compared with sleep, total sleep deprivation was associated with an increased activation in the right anterior cingulate cortex in response to food images, independent of calorie content and prescan hunger ratings. Relative to the postsleep condition, in the total sleep deprivation condition, the activation in the anterior cingulate cortex evoked by foods correlated positively with postscan subjective appetite ratings. Self-reported hunger after the nocturnal vigil was enhanced, but importantly, no change in fasting plasma glucose concentration was found.Conclusions:These results provide evidence that acute sleep loss enhances hedonic stimulus processing in the brain underlying the drive to consume food, independent of plasma glucose levels. These findings highlight a potentially important mechanism contributing to the growing levels of obesity in Western society.
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| 2. |
- Brooks, Samantha J., et al.
(författare)
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Differential Neural Responses to Food Images in Women with Bulimia versus Anorexia Nervosa
- 2011
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:7, s. e22259-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Previous fMRI studies show that women with eating disorders (ED) have differential neural activation to viewing food images. However, despite clinical differences in their responses to food, differential neural activation to thinking about eating food, between women with anorexia nervosa (AN) and bulimia nervosa (BN) is not known. Methods: We compare 50 women (8 with BN, 18 with AN and 24 age-matched healthy controls [HC]) while they view food images during functional Magnetic Resonance Imaging (fMRI). Results: In response to food (vs non-food) images, women with BN showed greater neural activation in the visual cortex, right dorsolateral prefrontal cortex, right insular cortex and precentral gyrus, women with AN showed greater activation in the right dorsolateral prefrontal cortex, cerebellum and right precuneus. HC women activated the cerebellum, right insular cortex, right medial temporal lobe and left caudate. Direct comparisons revealed that compared to HC, the BN group showed relative deactivation in the bilateral superior temporal gyrus/insula, and visual cortex, and compared to AN had relative deactivation in the parietal lobe and dorsal posterior cingulate cortex, but greater activation in the caudate, superior temporal gyrus, right insula and supplementary motor area. Conclusions: Women with AN and BN activate top-down cognitive control in response to food images, yet women with BN have increased activation in reward and somatosensory regions, which might impinge on cognitive control over food consumption and binge eating.
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| 3. |
- Brooks, Samantha J, et al.
(författare)
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Restraint of appetite and reduced regional brain volumes in anorexia nervosa : a voxel-based morphometric study
- 2011
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Ingår i: BMC Psychiatry. - 1471-244X. ; 11, s. 179-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Previous Magnetic Resonance Imaging (MRI) studies of people with anorexia nervosa (AN) have shown differences in brain structure. This study aimed to provide preliminary extensions of this data by examining how different levels of appetitive restraint impact on brain volume.METHODS:Voxel based morphometry (VBM), corrected for total intracranial volume, age, BMI, years of education in 14 women with AN (8 RAN and 6 BPAN) and 21 women (HC) was performed. Correlations between brain volume and dietary restraint were done using Statistical Package for the Social Sciences (SPSS).RESULTS:Increased right dorsolateral prefrontal cortex (DLPFC) and reduced right anterior insular cortex, bilateral parahippocampal gyrus, left fusiform gyrus, left cerebellum and right posterior cingulate volumes in AN compared to HC. RAN compared to BPAN had reduced left orbitofrontal cortex, right anterior insular cortex, bilateral parahippocampal gyrus and left cerebellum. Age negatively correlated with right DLPFC volume in HC but not in AN; dietary restraint and BMI predicted 57% of variance in right DLPFC volume in AN.CONCLUSIONS:In AN, brain volume differences were found in appetitive, somatosensory and top-down control brain regions. Differences in regional GMV may be linked to levels of appetitive restraint, but whether they are state or trait is unclear. Nevertheless, these discrete brain volume differences provide candidate brain regions for further structural and functional study in people with eating disorders.
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| 4. |
- Brooks, Samantha J., et al.
(författare)
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Subliminal food images compromise superior working memory performance in women with restricting anorexia nervosa
- 2012
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Ingår i: Consciousness and Cognition. - : Elsevier BV. - 1053-8100 .- 1090-2376. ; 21:2, s. 751-763
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Tidskriftsartikel (refereegranskat)abstract
- Prefrontal cortex (PFC) is dysregulated in women with restricting anorexia nervosa (RAN). It is not known whether appetitive non-conscious stimuli bias cognitive responses in those with RAN. Thirteen women with RAN and 20 healthy controls (HC) completed a dorsolateral PFC (DLPFC) working memory task and an anterior cingulate cortex (ACC) conflict task, while masked subliminal food, aversive and neutral images were presented. During the DLPFC task, accuracy was higher in the RAN compared to the HC group, but superior performance was compromised when subliminal food stimuli were presented: errors positively correlated with self-reported trait anxiety in the RAN group. These effects were not observed in the ACC task. Appetitive activation is intact and anxiogenic in women with RAN, and non-consciously interacts with working memory processes associated with the DLPFC. This interaction mechanism may underlie cognitive inhibition of appetitive processes that are anxiety inducing, in people with AN.
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| 5. |
- Walton, Esther, et al.
(författare)
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Brain Structure in Acutely Underweight and Partially Weight-Restored Individuals With Anorexia Nervosa : A Coordinated Analysis by the ENIGMA Eating Disorders Working Group
- 2022
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Ingår i: Biological Psychiatry. - : Elsevier. - 0006-3223 .- 1873-2402. ; 92:9, s. 730-738
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Tidskriftsartikel (refereegranskat)abstract
- 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. To clarify the extent, magnitude, and de-pendencies of gray matter changes in AN, we conducted a prospective, coordinated meta-analysis of multicenter neuroimaging data.METHODS: We analyzed T1-weighted structural magnetic resonance imaging scans assessed with standardized methods from 685 female patients with AN and 963 female healthy control subjects across 22 sites worldwide. In addition to a case-control comparison, we conducted a 3-group analysis comparing healthy control subjects with acutely underweight AN patients (n = 466) and partially weight-restored patients in treatment (n = 251).RESULTS: In AN, reductions in cortical thickness, subcortical volumes, and, to a lesser extent, cortical surface area were sizable (Cohen's d up to 0.95), widespread, and colocalized with hub regions. Highlighting the effects of un-dernutrition, these deficits were associated with lower body mass index in the AN sample and were less pronounced in partially weight-restored patients.CONCLUSIONS: The effect sizes observed for cortical thickness deficits in acute AN are the largest of any psychiatric disorder investigated in the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Consortium to date. These results confirm the importance of considering weight loss and renutrition in biomedical research on AN and underscore the importance of treatment engagement to prevent potentially long-lasting structural brain changes in this population.
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