Alternatively, they might take longer to process and understand the information they are accessing from the eyes. In addition, the authors point to recent work showing deficits in executive function and working memory tasks in Williams syndrome highlighting the possibility of attentional control problems in such patients.
This discovery suggests the possibility that people with Williams syndrome find it difficult to disengage their attention from faces. Because attention shifting deficits have also been reported for autism, Riby and Hancock propose that the relationship between the prefrontal cortex involved in inhibiting behavior and the amygdala involved in emotion processing may be crucial in both of these neuro-developmental disorders. Future work will, I hope, shed light on the neural underpinnings of these disorders and allow us to better understand why humans are such social animals.
Are you a scientist? Have you recently read a peer-reviewed paper that you want to write about? Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Go Paperless with Digital. Get smart. Sign up for our email newsletter. Causes of Charles Bonnet syndrome The underlying mechanism of Charles Bonnet syndrome is not understood. Doctors know that vision loss triggers the visual hallucinations.
It is not clear how the brain stores visual information, but we know that visual information from the eyes stops the brain from creating its own images.
Types of hallucinations in Charles Bonnet syndrome Generally, the hallucinations tend to occur when the person is alone, quiet and in a familiar environment, for example, when lying awake in bed. The two types of visual hallucination most common to Charles Bonnet syndrome include: Simple — such as patterns and lines, for example, the person may see brickwork images, netting or mosaics Complicated — such as seeing people, buildings, landscapes or places.
Complicated hallucinations are more likely to occur in people with severe vision loss. Features of Charles Bonnet hallucinations The features of hallucinations can vary widely from one episode to the next and from one person to the next.
For example, the images may be: colour, or black and white static like a photograph, or moving like an event in real life life-sized, or reduced in size realistic such as animals from the real world , or fantastic such as mythological monsters brief they continue for a few minutes , or lengthy they persist for a few hours enjoyable like a pleasant dream, or frightening like a nightmare meaningless and random, or featuring familiar people or familiar places different every time, or a person may see the same items in every hallucination.
Complications of Charles Bonnet syndrome A person with Charles Bonnet syndrome has no control over their hallucinations.
They may cause issues in their everyday life because: The hallucinations overlay images of the real world, so the person may have trouble negotiating everyday tasks, such as walking through an unfamiliar environment.
The person may not know at first whether the image is real or imagined, which can be frightening if they are seeing, for example, a stranger in the house. The person may fear they are going mad or exhibiting signs of dementia.
Diagnosis of Charles Bonnet syndrome Diagnosis of Charles Bonnet syndrome may include: your medical history a physical examination an eye examination medical tests to rule out other causes of visual hallucinations.
Treatment for Charles Bonnet syndrome In most cases, Charles Bonnet syndrome resolves itself after about 12 to 18 months without treatment. It is a good idea to find out everything you can about Charles Bonnet syndrome. Understanding the condition can help to reduce feelings of anxiety and helplessness. Depending on the severity of the condition, treatment may include: Medical advice — talking it over with a doctor or counsellor can be helpful.
Vision therapy — low-vision rehabilitation may help to ease symptoms. For example, one man with Charles Bonnet syndrome has described how when he wakes up in the morning, he says, "Right, what have you got in store for me today?
This allows him to have some control over the way he feels about his visions. If you have Charles Bonnet syndrome, talking about your hallucinations and how they make you feel may help you cope better. Mental health professionals, such as counsellors, psychologists or psychiatrists, may also be able to help if you're finding the hallucinations particularly upsetting. Although Charles Bonnet syndrome isn't a mental health condition, many mental health professionals have experience of helping people come to terms with hallucinations.
Read more about counselling and psychotherapy. There aren't many specific support groups and forums for people affected by Charles Bonnet syndrome, but there are lots of support groups for people with vision loss. The Macular Society can put you in touch with someone with Charles Bonnet syndrome who's also experienced visual hallucinations for support and reassurance. Their helpline number is 30 30 Monday to Friday, 9am to 5pm and their email address is: help macularsociety. Esme's Umbrella , an awareness campaign for Charles Bonnet syndrome, has a website with links to information and helpful resources for both patients and healthcare professionals.
You can also call the RNIB helpline on or contact them by email: helpline rnib. Page last reviewed: 27 November Next review due: 27 November Charles Bonnet syndrome. They're only visual and don't involve hearing things or any other sensations.
Always see your GP if you're experiencing hallucinations so they can investigate the cause. Types of hallucination There are 2 main types of hallucination that people with Charles Bonnet syndrome tend to experience. They may see: simple repeated patterns complex images of people, objects or landscapes Simple repeated patterns can take the form of grids, shapes or lines, which can appear in bright or vivid colours.
More complex hallucinations can involve people, places, animals and insects. Most people don't see hallucinations of people they know or past events they have experienced. They can sometimes occur out of the blue, and can last for a few minutes or several hours.
They may be moving or static. Who's affected and why?
0コメント