Trippy patterns and funky shapes can be found in ancient cave art from different parts of the world. How to explain it? Try magic mushrooms. Japanese researchers who analyzed drawings going back 40,000 years think prehistoric artists were high on hallucinogenic drugs, reports Live Science. The drugs brought on "geometric hallucinations" known as Turing instabilities—neural patterns that mimic the brain's own structure, say the researchers in Adaptive Behavior.
"When these visual patterns are seen during altered states of consciousness, they are directly experienced as highly charged with significance," the researchers write. In fact, modern humans under hallucinogens produce similar psychedelic images. This isn't the first time such a theory has been floated, but this study is the first with genuine "scientific rigor" to make the point, writes Adam Clark Estes at Gizmodo. The paintings "teach us a lot about mankind through the ages," he adds. "They teach us not only that we've always loved art, but that we've always loved drugs, too." (Read more cavemen stories.)