Homo sapiens nearly went extinct when their population fell to around 1,500 individuals. As they migrated through the Central African rainforest — where elephants were observed eating iboga and behaving strangely — over 100,000 years of potential iboga use may have stimulated the frontal cortex expansion that created human consciousness. A Columbia neuroscientist describes iboga as 'a spa for the neurons' that interacts everywhere in the brain simultaneously.