Macular degeneration is a disease of the eye retina which causes progressive deterioration of the central area of the retina--leads to loss of vision in the center of the field of vision — while the peripheral vision is usually not affected. In Australia, MD is the leading cause of blindness in people over the age of 40 years.
Early explanations of Hallucinations in macular degeneration
Why do some people with MD experienced hallucinations while others are not, it is still unclear, but there are suggestions that the level of activity of the visual area of the brain can play a role in a significant way.
To resolve it, Professor Jason Mattingley and his team from the Queensland Brain Institute and school of Psychology University stimulates peripheral visual field of research participants and found that individuals with hallucinations, it shows significantly increased activity in a specific part of their visual system.
Criteria for the diagnosis of macular degeneration Charles Bonnet Syndrome
"We're using electroencephalography (EEG) to measure the electrical activity of the brain in three groups: a group with macular degeneration and hallucinations of Charles Bonnet, groups with macular degeneration and without hallucinations, and a control group of people a healthy old visually, "Dr David light Painter, author of the research results in
"Their duty is to see the letters that appear at the edges of the screen, and we discuss flash Chess Board on the frequency in the display. We found that the boards of these oscillations generate unique visual area in the brain that we can measure using mathematical techniques. The main findings are when we encourage activity in the visual system of people with macular degeneration who reported experiencing hallucinations, there is a very large visual response compared with participants who have vision loss that the same but do not have a hallucination. "
Dr. Painter notes that while people with macular degeneration who experience visual hallucinations indicate hyperexcitability, the translation of these into a hallucinatory hyperexcitability is not automatic and depends on external trigger still unknown.
"During testing, none of our participants who experience hallucinations, so not because of an increase in stimulation of the brain produce hallucinations it is another factor, " Dr Painter.
"Sometimes people experience hallucinations when they are in a period of sensory stimulation is low, such as in low light or period of inactivity, but for others it can be triggered by things such as riding in a car or a television-it varies for each individual. "
"What our results is that the brain of the respondents who have experienced hallucinations were more upbeat, but it remains unclear how the stimulus is then translated into a hallucination-it is a question for future research."
These findings can help reduce misdiagnosis hallucinations in people with MD.
"When people get older and they begin to experience this unusual experience, they are often worried that there is something wrong with them, such as dementia or something similar, so they tend not to report hallucinations due to fearing they may be treated differently, "said Dr. Painter.
"Doctors sometimes do not recognize his illness, and therefore can only provide an inappropriate remedy to people, but our method could potentially allow us to detect those who may be suffering from Charles Bonnet Syndrome with see their brain stimulation in response to flashing stimulus. "
"Once people realize it's not a disorder of the brain, they tend to have a neutral or even positive experience of their hallucinations. Unlike the hallucinations in people with schizophrenia, for example, individuals with Charles Bonnet Syndrome are aware that they are not real hallucinations. "