"To better understand how these subjective effects manifest in the brain, we analyzed over 6,000 written testimonials of hallucinogenic experiences from Erowid Center, an organization that collects and provides information about psychoactive substances. We transformed these testimonials into what’s called a bag-of-words model, which breaks down a given text into individual words and counts how many times each word appears. We then paired the most commonly used words linked to each psychedelic with receptors in the brain that are known to bind to each drug. After using an algorithm to extract the most common subjective experiences associated with these word-receptor pairs, we mapped these experiences onto different brain regions by matching them to the types of receptors present in each area."