An experiment involving electrical stimulation to specific areas of the brain caused a subject to experience vivid visual hallucinations drawn from his memories, and to combine his current environment with images drawn from his life, according to a recent New Science report.
In a striking example, the subject, who volunteered for the project, hallucinated that the team of researchers were transformed into Italian workers at his family’s pizza restaurant, complete with aprons.
The results were first published in The Journal of Neuroscience earlier this month, and were the findings of a team led by Pierre Mégevand of the Feinstein Institute for Medical Research in New York. One of the co-authors of the study was US-based Israeli neuroscientist Ido Davidesco, who teaches at both Princeton University and the Rehovot-based Weizmann Institute of Science.
The subject, a 22-year-old man suffering from epilepsy, was first shown various images while under an MRI-scan, which tracks brain activity. Specific areas of his brain showed activity when he looked at the various images, results which were later corroborated by implanting electrodes in the same locations and showing the subject the same pictures, which resulted in electrical activity at the same specific areas.
The researchers then stimulated these areas specifically, which caused the subject to experience strong visual hallucinations, which he said had no auditory or olfactory component.
Stimulation to one specific area caused the subject to see a railway station near his house, and stimulation to a nearby area caused him to see a stairwell and closet in his home, the subject said. Repeat stimulation caused visions of the same scenes.
Then, the researchers stimulated another series of nearby areas, which resulted in hallucinations based on the subject’s current circumstances combined with images from his memory. In one area, the team of researchers’ faces become distorted and twisted, and in other area, the subject said that the team “suddenly all looked Italian and like they were working in his family’s pizzeria, ‘with aprons and whatnot.'”
One of the researchers said that the subject laughed during the experiments and “got a kick out of it… he thought it was sort of trippy and funny.”
The research sheds light on areas of the brain used to process specific images and memories, and could in the future be used in non-invasive treatment for those suffering from conditions such as autism or Alzheimer’s, the researchers said.