Can you induce hallucinations

These lights were flashing about 2. But the volunteers were experiencing hallucinations consistent with lights flashing about five times per second. The signals from the two eyes were being combined in the brain to create a stronger and faster hallucination. This combination of the signals from the two eyes really only happens in the visual cortex, not in the eye, or other early processing areas of the brain that receive visual input before it gets to the cortex.

Currently, we are testing this new method for inducing and measuring hallucinations in people with neurological disorders to reveal more about how clinical hallucinations are experienced and processed in the brain. If we can discover the underlying mechanisms of visual hallucinations, this will give us targets to focus treatments on. We hope this new technique will open the doors to new avenues of research, not only shedding light on the foundations of human consciousness, but also helping to develop innovative new treatments for those suffering from hallucinations.

Festival of Social Science — Aberdeen, Aberdeenshire. Edition: Available editions United Kingdom. Become an author Sign up as a reader Sign in. Healthy people can have visual hallucinations after taking drugs, being sleep deprived or suffering migraines.

After spending 15 minutes deprived of sight and sound, each person completed a test called the "Psychotomimetic States Inventory," which measures psychosis-like experiences and was originally developed to study recreational drug users.

Among the nine participants who scored high on the first survey, five reported having hallucinations of faces during the sensory deprivation, and six reported seeing other objects or shapes that weren't there.

Four also noted an unusually heightened sense of smell, and two sensed an "evil presence" in the room. Almost all reported that they had "experienced something very special or important" during the experiment. As expected, volunteers who were less prone to hallucinations experienced fewer perceptual distortions, but they still reported a variety of delusions and hallucinations.

The researchers were not altogether surprised by such dramatic results from only 15 minutes of sensory deprivation. The authors explain how scientists can evaluate lab models to work out how to apply the findings to pathological states and suggest new possible research directions with induced hallucinations. They hope further study will provide deeper, objective understanding of the underlying cognitive and neural processes as well as how and why they occur in various diseases, thus assisting with treatments.

It could also offer broader insights into human consciousness, says Rogers. Originally published by Cosmos as Would you hallucinate for science? Natalie Parletta is a freelance science writer based in Adelaide and an adjunct senior research fellow with the University of South Australia. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Most of these participants were relatively easy to recruit.

Powers and Corlett wanted to know if people diagnosed with psychoses had brains that operated differently than the other subjects. The team conditioned participants to associate a checkerboard pattern with a 1-kHz tone, which sounds like the bleep over a swear on late-night TV. Initially, the scientists sprinkled in lots of 1-kHz tones that they were certain the participants could hear. Then, as the task went on, they changed their intensity and often removed them entirely.

Like in a hearing test at the doctor, participants were asked to press a button when they heard the tone. In an added twist, participants could indicate how confident they were about their response.

Meanwhile, their brains were examined using magnetic resonance imaging MRI. That reinforced to Corlett and Powers that mental symptoms like hallucinations and delusions may exist on a continuum, from manageable occurrences to increasingly severe and disruptive clinical cases. Meanwhile, the group with known psychosis but no regular hallucinations responded differently. While most participants were unable to tell real tones from imagined ones, those in the psychotic, non-hallucinating group were more quickly and confidently able to determine the change.

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