The orbitofrontal cortex comprises the ventral surface of the frontal lobe, and is critical for functions ranging from olfaction and emotion to learning and behavioral flexibility. Since the time of Phineas Gage, this enigmatic brain region has intrigued clinicians due to its association with personality. Recent research has started to unmask the specific operational principles of the area. Simultaneously, advances in the clinical neurosciences increasingly implicate the orbitofrontal cortex and adjacent ventral frontal regions in a variety of psychiatric and neurological conditions including anxiety, mood and addictive disorders, as well as frontotemporal dementia. This volume provides the first comprehensive review of the orbitofrontal cortex, and should be a standard reference for established clinicians and researchers as well as trainees in neurology, neurosurgery, psychiatry, psychology, and neuroscience. The book starts with a review of the structure of the ventral frontal lobes in human and nonhuman primates and the current state of knowledge regarding the region's neurocircuitry. This is followed by a series of chapters addressing the precise functions of the orbitofrontal cortex, with coverage spanning animal and human research. The book continues with chapters detailing methodological issues in neuroimaging and neuropsychological assessment of the region, and concludes with reviews of the area's contribution to psychiatric and neurological conditions. With chapters throughout by leading experts, and a foreword from Marsel Mesulam, the volume provides both a basic foundation that will be useful to students, and critical reviews that capture the sophisticated nuances, controversies, and emerging concepts in the field.