She was a bit skeptical at first. But "I began to see results right away," she said, adding that, after the first few sessions, she got "hooked."
Hypnotherapy not only helped her to give up Beard Papa's chocolate éclairs, but it also gave her an "overall positive body image and mental outlook," she said.
In a country where more than one-third of adults are obese, according to the Centers for Disease Control, Corey is among a growing number of people exploring hypnotherapy as an alternative to conventional weight-loss methods.
Her instructor, Eric Rosen, was educated at the Palo Alto School of Hypnotherapy and currently offers classes through the City of Palo Alto Recreation Department, as well as the cities of Los Altos, Menlo Park, Cupertino, Sunnyvale and Saratoga.
In his classes and private sessions, Rosen uses hypnosis to suggest to his students and clients that they make smart food choices, avoid binge-eating and be attentive during meals by jotting down their food consumption before and after. He gently encourages them to choose organic foods over processed ones and embrace "super foods" such as broccoli, spinach and soy.
His classes, he said, focus on helping people to visualize their goals and change their food habits.
Hypnosis, by itself, might not be a "magic bullet" to solve the complex problem of losing weight. As a supplement to a comprehensive weight-loss program, however, it can help people lose "significantly more weight," according to a study by Dr. David Spiegel, professor of psychiatry and behavioral sciences at Stanford University and director of the Stanford Center for Integrative Medicine.
Weight loss is only one of many health problems that hypnotherapists are trying to tackle; others include controlling anxiety before and during medical procedures, headaches, smoking, pain, hot flashes in breast cancer survivors and irritable bowel syndrome, according to the National Center for Complementary and Alternative Medicine.
Derived from the Greek word "hypnos" meaning sleep, hypnosis guides people into a psychological state in which a person's awareness and concentration are heightened.
"It is something like looking through a telephoto lens in a camera," Spiegel said in an interview with the Weekly.
Hypnotists use this "hyper-attentive" state to get people to focus on a particular thought or memory, tap into their pain and anxiety, and work towards resolving them.
Many experts regard hypnosis as a deeper form of daydreaming — a far cry from the image of magical mind-control created by Las Vegas stage-show performers.
When people "lose themselves" in a book or a movie, or lose track of time while driving, they are essentially putting themselves in a hypnosis-like trance. Self-hypnosis can be a powerful tool to help the mind identify and solve its problems, practitioners say, and most hypnotherapists teach self-hypnosis to their patients during or after the first few sessions.
The practice of hypnosis dates back to Ancient Egyptian "sleep temples," more than 4000 years ago.
Many websites describe how hypnosis moved initially from the realm of the irrational to that of the scientifically acceptable in the 19th century. Two surgeons' work aided in the acceptance. One used hypnosis to anesthetize patients during surgery, and the other tried to establish a scientific explanation for the phenomenon.
In 1958 the American Medical Association approved and encouraged research on the medical uses of hypnosis, and two years later, the American Psychological Association endorsed hypnosis as a branch of psychology.
Despite its history, scientists are still trying to figure out how exactly hypnosis influences the brain.
Most popular theories suggest that it works by "switching off" the rational, decision-making part of the brain that focuses on day-to-day activities, in order to unlock the more creative, unrestrained part.
This idea has received some support from EEG studies of hypnotized subjects showing higher brain-wave activity typically associated with sleep and dreaming. Other studies conducted in the 1960s and 1970s had proposed that hypnosis is mediated by the right hemisphere — the part of the brain that may control imagination and impulse — perhaps explaining why people under hypnosis are more likely to act on foolish suggestions by stage-show hypnotists. These and other hypnosis-related studies were reviewed in a 2012 article by Professor John Kihlstrom, from the University of California, Berkeley, in the journal Cortex.
"We do know, for sure, that people in the trance state can alter their perceptions; sensory regions in the brain will literally turn down their response to pain input and change their perception of color, smell or hearing," Spiegel explained. He added that hypnosis also appears to have an effect on the part of the brain that helps us process attention.
Some people are more easily hypnotized than others.
Children and adults who are "easily absorbed into activities such as reading, listening to music or daydreaming" are thought to be more easily hypnotized, a University of Tennessee psychology professor wrote in a 2001 Scientific American article.
Though the inner workings of hypnosis are still obscure, there are some established techniques that hypnotherapists employ to guide their patients into a hypnotic trance, few of which involve a swinging pocket watch or exotic crystals.
Most use progressive relaxation and guided imagery, which involve breathing techniques and invoking positive and calming images to help people enter the hypnotic trance.
Mary Horngren, another hypnotherapist educated at the Palo Alto School of Hypnotherapy, uses this technique to help cancer patients at the Palo Alto Medical Foundation and Breast Cancer Connections prepare for surgery and cope with their pain and anxiety.
During her sessions, she guides them through a sort of "dry-run" of the surgery or treatment, focusing on positive thoughts so that they are well prepared when the time comes.
At the Stanford Center for Integrative Medicine, Spiegel uses hypnosis to help patients manage their pain. Hypnosis can reduce pain by half on the same amount of medication, he said.
Under hypnosis, patients learn to draw out their pain — essentially "bringing it on," Spiegel said — and then learn to "control and separate their psychological response from their physical response."
He said that he has also been able to help people quit smoking using hypnosis, with one out of four patients ending up not touching a cigarette after just one session of hypnosis.
Spiegel also used hypnosis on Palo Alto resident Kenneth Fitzhugh, who was charged in his wife's murder and put on trial in 2000. Fitzhugh testified that the 50-minute hypnosis session unlocked repressed memories explaining his connection to pieces of physical evidence in his vehicle. Fitzhugh was later convicted of the crime.
However, the application of hypnosis to forensics is still controversial and highly debated.
Despite its use in medical settings, hypnosis still faces skepticism and is often dismissed as a "pseudoscience," which is why hypnotherapists like Horngren strive to raise the level of respect for the practice.
"It is their fear of losing control," she said, explaining why people still have misconceptions about the practice.
"Hypnosis is one of the safest procedures and has far fewer side effects that any other medication or procedure," Spiegel said. Bad experiences with unreliable or untrustworthy hypnotherapists could fuel this skepticism, he added, but the techniques themselves are well-established.
Currently, no specific agency or board licenses and regulates the practice of hypnotherapy, although there are schools such as the Palo Alto School of Hypnotherapy — recognized by the Bureau of Private Postsecondary Education in California — that offer courses and certification in medical and clinical hypnotherapy.
Doctors and psychiatrists belonging to professional organizations such as the American Psychiatric Association and the American Medical Association have strict standards and guidelines for the professional practice of hypnotherapy.
"It is extremely important to establish a rapport between the hypnotist and the patient/client ... to remain above the board with them," Rosen said.
Diana O'Hagin, who used hypnosis decades ago to give up smoking, said Rosen recorded all of their sessions for her reference and to keep her appraised of her progress.
Some people still question whether hypnosis can make a person do something they don't want to, but practitioners dispute that belief. While "one's critical judgment is suspended," as Spiegel described it, hypnotherapists can only show someone how to achieve what they want, according to Rosen.
Horngren echoed this sentiment.
"It is all about helping people help themselves," she said, adding that she only acts as a facilitator, guiding them through the healing process.