Toxicologist Albert Donnay believes that chronic exposure to substances such as carbon monoxide, pesticide, and formaldehyde can lead to hallucinations of the type associated with haunted houses. Donnay speculates on the connection between the prevalence of gas lamps, during the Victorian era and start of the 20th century, as well as stories of ghost sightings and hauntings, describing it as the "Haunted House Syndrome". Donnay says that carbon monoxide poisoning has been linked to haunted houses since at least the 1920s. He cites a 1921 journal article about a family who claimed hauntings because they suffered headaches, auditory hallucinations, fatigue, melancholy, and other symptoms which are also associated with carbon monoxide poisoning. In a modern example, Carrie Poppy, a writer and co-host of the podcast "Oh No, Ross and Carrie!", was convinced she was living in a haunted house. She felt she was being watched by a demon, experienced pressure on her chest and auditory hallucinations. Someone on a forum of skeptical paranormal investigators suggested she look into carbon monoxide poisoning. When the gas company arrived, unsafe levels of carbon monoxide were found. Michael Persinger, an American-Canadian professor of psychology, suggested that perceived apparitions, cold spots, and ghostly touches are perceptual anomalies caused by variations in naturally occurring or man-made magnetic fields. However, a study by psychologist Chris French that attempted to replicate Persinger's findings found no link. Investigations of supposed hauntings often result in simple explanations. For example, in an apparent haunted house in Somerset, England, in the eighteenth century, a boy would make the house shake by jumping on a beam in an adjoining property that ran through both houses. In 1857, a twelve-year-old girl confessed to tying her long hair around objects to give them the ghostly appearance of moving on their own. Tina Resch, a Columbian girl who claimed that ghostly and paranormal activity occurred in her home, was photographed throwing a telephone while acting surprised at the sudden poltergeist activity. Ben Radford, of the Committee for the Scientific Investigation of Claims of the Paranormal, performed an investigation in 2003 on an allegedly haunted house in Buffalo, New York. The owner of the home, called Tom in the article (real names not used), alleged that he felt tapping on his foot at night. As described by Tom, “I get a tapping on my feet, not a repetitive tap, a trying-to-wake-you-up tap… After the tapping, if I don’t pay attention to it, then I feel a kick.”