Cortical mechanisms of human eating.
ABSTRACT The hedonic component of eating is an underexplored topic within neuroscience, which is surprising given its importance for our survival and general well-being, as well as the obvious links to obesity and eating disorders. Based on findings from neuroimaging, this review gives an overview of the established principles, neural mechanisms and functional neuroanatomy of the primate and human brain processing systems involved in controlling eating. Four main processing principles underlying these processes are discussed: (1) motivation-independent discriminative processing of identity and intensity, (2) formation of learning-dependent multimodal sensory representations, (3) reward representations using mechanisms including selective satiation, and (4) representations of hedonic experience, monitoring/learning or direct behavioural change.
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ABSTRACT: Neuroimaging is becoming increasingly common in obesity research as investigators try to understand the neurological underpinnings of appetite and body weight in humans. Positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and magnetic resonance imaging (MRI) studies examining responses to food intake and food cues, dopamine function and brain volume in lean vs. obese individuals are now beginning to coalesce in identifying irregularities in a range of regions implicated in reward (e.g. striatum, orbitofrontal cortex, insula), emotion and memory (e.g. amygdala, hippocampus), homeostatic regulation of intake (e.g. hypothalamus), sensory and motor processing (e.g. insula, precentral gyrus), and cognitive control and attention (e.g. prefrontal cortex, cingulate). Studies of weight change in children and adolescents, and those at high genetic risk for obesity, promise to illuminate causal processes. Studies examining specific eating behaviours (e.g. external eating, emotional eating, dietary restraint) are teaching us about the distinct neural networks that drive components of appetite, and contribute to the phenotype of body weight. Finally, innovative investigations of appetite-related hormones, including studies of abnormalities (e.g. leptin deficiency) and interventions (e.g. leptin replacement, bariatric surgery), are shedding light on the interactive relationship between gut and brain. The dynamic distributed vulnerability model of eating behaviour in obesity that we propose has scientific and practical implications.Obesity Reviews 09/2011; 13(1):43-56. · 7.04 Impact Factor