The post reviews research on adult neurogenesis, initially presenting evidence for its existence and importance, then reveals a new study suggesting it doesn't occur in humans, examining the implications of this potential field-wide error. Longer summary

This post reviews the literature on adult neurogenesis, initially presenting numerous studies that claimed to find evidence for the generation of new neurons in adult human brains. These studies linked adult neurogenesis to various aspects of brain function, including memory, learning, and depression. However, the post then reveals a new study suggesting that adult neurogenesis doesn't actually occur in humans, or is so rare as to be insignificant. The author examines how this field-wide error could have occurred, discussing the extrapolation of rat studies to humans and the role of confirmation bias. The post ends by reflecting on the implications of this for scientific research and the replication crisis. Shorter summary