Cortical and Limbic Activation in Response to Low- and High-calorie Food

The complex decisions about what and how much to eat are ultimately guided by the interplay of multiple neural systems within the brain. Recent advances in neuroimaging technologies have made it possible to observe directly the responses of the human brain to a variety of stimuli and cues associated with food, hunger, taste, smell, and other influences on eating-related behavior. Techniques such as positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have proven useful in mapping the regions of the human brain that are activated in response to food-related stimuli. They are providing important clues that may help explain why many people may find it difficult to resist certain foods, particularly those that are most implicated in weight-related problems. While the neuroimaging literature on brain responses to food and eating related stimuli has expanded rapidly in recent years, this chapter focuses primarily on a circumscribed set of fMRI studies that have explored how the brain responds to visual images of foods that differ in their caloric content. This review is not meant to be exhaustive but rather highlights some of the specific neural systems that may be particularly relevant to the initial responses people have when first seeing something edible.