Thursday, February 9, 2012

Skewed Perception - That's delusional!

Internet Debris

A collection by Neal McKenna 

McKenna Ink Thesis Editing Service 

To add your comments, 

click here.

NOTHING posted here is mine! 

Internet Debris does not claim rights 

to any of the photos or media content posted to the site.

No copyright infringement is intended.

Seeing Impostors: 

When Loved Ones Suddenly Aren't

Magritte's painting, The Intimate Newspaper
Rene Magritte/Corbis
Magritte's 1964 painting The Intimate Newspaper gets us thinking: Who is this? A familiar friend or a complete stranger?

Fall For An Illusion

In the classic 1956 film Invasion of the Body Snatchers, the residents of a fictional town in California are beset by the feeling that their friends and family have been replaced by impostors. In the movie, this apparent delusion is not delusional at all: The townspeople are in fact being replaced — by aliens, no less.
Numerous sci-fi films since have capitalized on our fear of being surrounded by duplicates — replicas who look just like our loved ones but are not. And while there have so far been no confirmed cases of a human being replaced by an alien or any other life-form, the feeling that your loved one has been replaced by someone else can be very real.

Consider these two true stories:

A 37-year-old woman came into the office of Carol Berman, a psychiatrist at New York University Medical Center, with a strange complaint. She had returned to her house recently to find a man sitting on her couch. He was familiar, sort of, and he was wearing her husband's clothes. But something didn't feel right to this woman. She felt a strange kind of emptiness when she looked at him. She was struck by the very deep sense that her husband had somehow been replaced by this strange man.
A student at the University of California, San Diego was severely injured in a car accident. After several weeks in a coma, he regained consciousness and seemed to be doing fine. But according to V.S. Ramachandran, a neuroscientist at the university, when the patient's mother came to see him, he exclaimed, "Who is this woman? She looks just like my mother, but she's an impostor! She's some other woman pretending to be my mother."

Rare Delusional Disorder

Both patients, it turns out, were suffering from a rare delusional disorder, called Capgras. Capgras delusion can be brought about by a variety of conditions — changes in brain chemistry associated with different mental illnesses, or physical trauma to the brain — but the delusion always involves the distinct feeling that the people around you have been replaced by impostors. While they may look and act just like the real person, some essence of the person is missing, almost as though "the soul of the person isn't in there," Berman says.
Jean Marie Joseph Capgras during WWII
Courtesy of Douwe Draaisma
Capgras delusion was first identified by French psychiatrist Joseph Capgras. In a 1923 paper, he wrote about a patient, "Madame M," who for 10 years had been "transforming everyone in her entourage, even those closest to her, such as her husband and daughter, into various and numerous doubles."
Currently, no one is certain of the underlying cause of Capgras, and there are different ways of explaining what is happening to these people. According to Berman, Capgras might be caused by psychological dissonance. There are usually things about the people close to us that we don't like. Normally, we combine these things with the parts we do like and develop a general emotional response to the whole person. But in some extreme cases, a change in character or a newly noticed behavior can just be too difficult to accept, to integrate into the whole. And so, rather than reframing our sense of who that person is, our brain just says: "That must not really be him."
Ramachandran thinks that Capgras can be better explained by a structural problem in the brain. According to Ramachandran, when we see someone we know, a part of our brain called the fusiform gyrus identifies the face: "That looks like mom!" That message is then sent to the amygdala, the part of our brains that activates the emotions we associate with that person. In patients experiencing Capgras, Ramachandran says, the connection between visual recognition and emotional recognition is severed. Thus the patient is left with a convincing face — "That looks like mom!" — but none of the accompanying feelings about his mother.

That's Not My Mother

Ramachandran holds that we are so dependent on our emotional reactions to the world around us, that the emotional feeling "that's not my mother" wins out over the visual perception that it is. The compromise worked out by the brain is that your mother was somehow replaced, and this impostor is part of a malevolent scheme.
Ramachandran thinks there's good evidence for this explanation of Capgras, in part because of an odd quirk in his patient's behavior. When his mother calls him on the phone and he hears her voice, he instantly recognizes her. Yet if she walks in the room after that call, he is again convinced that she is an impostor.
Why? Ramachandran says that our visual system and auditory system have different connections to the amygdala, so while the auditory recognition triggers an emotional response in his patient, visual recognition does not.

Treating the Illness

Capgras is very rare, and little is known about how to treat it. Those who have been afflicted with Capgras due to physical brain trauma may eventually re-establish the connection between perception and emotion. (Ramachandran's patient, for example, eventually recovered from his delusion.) And patients who experience Capgras alongside other mental disorders may be helped by medication. But for many Capgras patients, there is no treatment, and no amount of talk or reasoning can cure them.
While the feeling that the people around you have been replaced by impostors is certainly terrifying to imagine, the effect on the supposed impostor can be devastating, too. Carol Berman's husband began suffering Capgras after the onset of a particular kind of dementia in which neural transmission between different parts of the brain decays. Some days he knows that Berman is his wife. But other days, the woman who walks through the door is an impostor.
"I hope he's recognizing me," says Berman, "but you never know what you're going to get when you get back home." 

Text and images via NPR 

Spoooky Reading 

Why A Brush With Death Triggers 

'The Slow-Mo Effect'


Tim Schapker/Flickr
When David Eagleman was 8 years old, he went exploring. He found a house under construction — prime territory for an adventurous kid — and he climbed on the roof to check out the view. But what looked like the edge of the roof was just tar paper, and — you can feel it coming — when David stepped on it, he fell. Whoosh… Thud!
David was fine. But between whoosh and the thud, something odd happened. As David remembers it, he noticed every detail of his surroundings: the edge of the roof moving past him, the red bricks below moving toward him. He even did a little literary analysis: "I was thinking about Alice in Wonderland, how this must be what it was like for her, when she fell down the rabbit hole."
All of that happened in just 0.86 seconds. David knows that now because he has calculated how long it takes to fall 12 feet. David Eagleman is now Dr. Eagleman, a neuroscientist at Baylor College of Medicine, and one of his specialties is exploring how our brains perceive and understand time.
Several years ago, motivated in part by his childhood plunge, David started studying the way our sense of time distorts in crisis situations. He has gathered a huge number of stories from people who have survived falls, car crashes, bike accidents, etc. Everyone, he says, seems to say the same thing: "It felt like the world was moving in slow motion."
But what is really going on? David started to think that maybe, in a crisis, the brain goes into a sort of turbo mode, processing everything at higher-than-normal-speed. If the brain were to speed up, he thought, the world would appear to slow down. This would work just like a slow-motion movie; in a slow-mo shot of a hummingbird, for example, you can see each individual wing movement in what would otherwise be just a blur.

Taking The Plunge

So David decided to craft an experiment to study this "slow-motion effect" in action. But to do that, he had to make people fear for their lives — without actually putting them in danger. His first attempt involved a field trip to Six Flags AstroWorld, an amusement park in Houston, Texas. He used his students as his subjects. "We went on all of the scariest roller coasters, and we brought all of our equipment and our stopwatches, and had a great time," David says. "But it turns out nothing there was scary enough to induce this fear for your life that appears to be required for the slow-motion effect."
But, after a little searching, David discovered something called SCAD diving. (SCAD stands for Suspended Catch Air Device.) It's like bungee jumping without the bungee. Imagine being dangled by a cable about 150 feet off the ground, facing up to the sky. Then, with a little metallic click, the cable is released and you plummet backward through the air, landing in a net (hopefully) about 3 seconds later.
SCAD diving was just what David needed — it was definitely terrifying. But he also needed a way to judge whether his subjects' brains really did go into turbo mode. So, he outfitted everybody with a small electronic device, called a perceptual chronometer, which is basically a clunky wristwatch. It flashes numbers just a little too fast to see. Under normal conditions — standing around on the ground, say — the numbers are just a blur. But David figured, if his subjects' brains were in turbo mode, they would be able to read the numbers.

The Time Blur

The falling experience was, just as David had hoped, enough to freak out all of his subjects. "We asked everyone how scary it was, on a scale from 1 to 10," he reports, "and everyone said 10." And all of the subjects reported a slow-motion effect while falling: they consistently over-estimated the time it took to fall. The numbers on the perceptual chronometer? They remained an unreadable blur.
"Turns out, when you're falling you don't actually see in slow motion. It's not equivalent to the way a slow-motion camera would work," David says. "It's something more interesting than that."
According to David, it's all about memory, not turbo perception. "Normally, our memories are like sieves," he says. "We're not writing down most of what's passing through our system." Think about walking down a crowded street: You see a lot of faces, street signs, all kinds of stimuli. Most of this, though, never becomes a part of your memory. But if a car suddenly swerves and heads straight for you, your memory shifts gears. Now it's writing down everything — every cloud, every piece of dirt, every little fleeting thought, anything that might be useful.
Because of this, David believes, you accumulate a tremendous amount of memory in an unusually short amount of time. The slow-motion effect may be your brain's way of making sense of all this extra information. "When you read that back out," David says,  
"the experience feels like it must have taken a very long time." But really, in a crisis situation, you're getting a peek into all the pictures and smells and thoughts that usually just pass through your brain and float away, forgotten forever.
Text and image via NPR

To add your comments, click on links to this post 

here or below. It will take you to a stand-alone copy of this page. There, you will find the comments box, so feel free to let 'er rip.

If you like what you see here

- tell your friends!

What lies beneath...

Image via Popper Font

No comments:

Post a Comment