is based on an attempt to understand the role of the nervous system and brain in mediating psychological and physical factors. Neuropsychology studies the effects of the brain and its functions on behavior, emotions, and cognitive ability, providing a scientific framework for understanding how chronic psychological stress or emotional disorders can cause neural changes associated with physical disorders. For example, neuropsychology explains how an overactive limbic system (in particular, the amygdala) leads to excessive stress responses, increased cortisol secretion, and weakened immunity, which affects a person’s somatic state and manifests itself in psychosomatic diseases such as cardiovascular disease or irritable bowel syndrome (IBS). Thus, psychosomatics relies on neuropsychological data to explain the neurocognitive changes that contribute to the development or persistence of somatic diseases.