Kluver-Bucy Syndrome

Kluver-Bucy syndrome is a rare and dramatic behavioral syndrome resulting from bilateral damage to the medial temporal lobes, especially the amygdala, producing a distinctive cluster of changes including hyperorality, a compulsive tendency to explore and examine objects by mouth, hypersexuality, an unusually placid temperament with a loss of normal fear and aggression responses, visual agnosia, an inability to recognize familiar objects or people by sight alone, and hyperphagia, or significantly increased eating. The American researchers Heinrich Kluver and Paul Bucy first documented the syndrome in a series of experiments on rhesus monkeys in the late 1930s, finding that surgically removing both temporal lobes produced this striking constellation of behavioral changes even though the animals' basic sensory functions remained largely intact. The syndrome was later observed in humans as well, most often following bilateral temporal lobe damage caused by conditions such as herpes simplex encephalitis, severe traumatic brain injury, or advanced neurodegenerative disease, though the full human presentation is typically less complete than the syndrome originally described in monkeys. The original Kluver-Bucy experiments are considered a landmark early contribution to the scientific understanding of how the temporal lobes and the amygdala in particular contribute to the regulation of fear, aggression, sexual behavior, and the ability to correctly interpret the emotional and social significance of what is seen.