Warning: The study's authors recommend that anyone with a history of migraines, epilepsy or psychiatric disorders refrain from watching the video below
Hallucinations are, by their nature, hard to study. People struggle to describe what they see, and efforts to have the hallucinator draw their visions seldom adds much precision. So Dr Joel Pearson of the University of New South Wales is excited about the potential of the first method to produce hallucinations that can be objectively measured.
Hallucinations caused by psychosis or drugs are usually too complex to measure on a single scale. For more than a century we have known that flickering lights, along with certain combinations of light and dark, can induce visual hallucinations, and these are simpler.
However, Pearson told IFLScience, they are still not simple enough. “It's like trying to study the imagination,” Pearson said. To change this, Pearson set out to reduce what is seen to be a single, quantifiable feature. He announced his success in eLife.
Pearson's hallucinogen works by flashing a white ring up to 30 times a second on a black background. A group of student volunteers without a history of migraines or epilepsy reported seeing gray blobs rotating inside the ring, and Pearson showed he could control the brightness of these blobs through the rate at which the ring flashed. When a second ring with permanent blobs was added, participants compared the brightness of the real and hallucinated blobs.
If the flickering doesn't give you a headache, you should be able to see the moving blobs. Joel Pearson