NORWICH, England >> In January 1953, William S. Burroughs went into the Colombian Amazon to look for drugs. Ayahuasca, to be specific, also called yage — one of the most potent hallucinogenic substances on Earth, and a fundamental aspect of the social and spiritual life of over 150 Indigenous Amazonian groups.

Burroughs documented the journey in “The Yage Letters,” an epistolary novel he cowrote with Allen Ginsberg, which was many Westerners’ introduction to the existence of ayahuasca. In a photograph of Burroughs from that trip, he’s leaning sweatily against a tree in the jungle, pith helmet in hand and a wild look in his eye. You’d struggle to find a better visual representation of the beginning of the psychedelic revolution, when the West began to realize that hallucinogens had uses far beyond the sacred or the ceremonial.

The photo is on display at a remarkable new exhibition series titled “Why Do We Take Drugs?” at the Sainsbury Center art museum in Norwich, England, devoted to examining drug use and culture around the world. Rather than becoming preoccupied with the question of whether or not we should be doing drugs, the project tries to understand why we always have.

The series begins with two shows, “Power Plants: Intoxicants, Stimulants and Narcotics” and “Ayahuasca & Art of the Amazon,” that look at psychoactive plants and the way cultural context shapes their radically different uses. (Shows exploring heroin, alcohol and antidepressants open this month.)

In one darkened room, with piped-in exotic bird sounds and low stools that look like tree stumps, visitors are invited to put on virtual-reality headsets and undergo, or endure, a 360-degree immersion, led by a CGI shaman, intended to simulate the experience of being on ayahuasca. A sign at the door warned that the 18-minute experience was unsuitable for people with claustrophobia or who are “prone to snake or insect phobia.”

I lasted about five minutes before nausea got the better of me, but there were indeed a lot of snakes and creeping things, endlessly dividing geometric shapes and the ridiculous but unshakable feeling that I might be stuck like this forever, watching spider patterns spin and mutate. It felt, in other words, like being on drugs.

Nausea was a recurring theme; throwing up, often for hours, is a common and intense side effect of ayahuasca. Grainy footage of a real shaman-led ayahuasca trip in the Amazon showed men vomiting wearily into plastic buckets before coming up for air and resuming their fixed expressions of stricken awe. A first-edition copy of “The Yage Letters,” displayed under glass, was helpfully opened to a drawing of a skeleton wearing sunglasses, captioned “The Vomiter.”

Despite these references to ayahuasca’s gnarly physical side effects, the show was overwhelmingly positive about this particular drug, emphasizing its place in the growth of the countercultural movement, its potential therapeutic uses, and its cultural and spiritual role among Indigenous groups.

One of the most striking rooms shows the work of Sara Flores, an artist from the Shipibo-Konibo people of the Peruvian Amazon, whose intricate paintings are inspired by visions experienced during plant-based rituals. In an interview with Flores in the exhibition catalog, she notes firmly that she does not consider ayahuasca a drug at all but rather a medicinal plant used to cure physical and spiritual problems.

The densely repeating geometric patterns found in Flores’ work were echoed in another section of the show, which focuses on drug trials conducted at the Center for Psychedelic Research at Imperial College London. Undertaken in 2017, the trials explored for the first time the effects of DMT, the main hallucinogenic component of ayahuasca, on the brain. In a clinical setting — hospital gowns, cannulas, electroencephalogram headsets, MRI scanners — volunteers were given an intravenous dose of DMT, which produced immediate and intense visual hallucinations, no vomiting required.

Once the effects had worn off, the participants were asked to try to draw what they had seen. Their responses were startlingly uniform: geometric compositions and anthropomorphic creatures emerging from constantly shifting radial patterns.

For neuroscientists such as Chris Timmermann, leader of the trials, the study showed that DMT acts on the cerebral mechanisms linked to imagination, dreaming and abstract thought. For me, the study has cleared up a mystery I have long wanted to solve: why Western psychedelic art (or what I think of as “Burning Man Art”) so often features exploding triangles, bug-eyed animals and flowers transforming into slightly different versions of themselves. It looks that way, it seems, because that is what happening inside our heads when we are on drugs. We have no one to blame but ourselves.

Departing visitors were invited to write down their answers to the question the series poses. Their contributions ranged from showily cynical (“Because you’re an insufferable middle class child on your gap year”; “Because the drug lords are good at marketing”) and heartbreaking (“I just want peace and quiet in my brain”) to the bizarrely specific (“To watch Pixar’s ‘Ratatouille’ and taste the food in your mind”).

My favorite was the most straightforward, from a person who explained that they took drugs to forget that they worked in a grocery store.