Turquoise Gulf waters this morning. Little
writing work accomplished yesterday but it was a good day nevertheless. Kim,
Paul and the boys are about to head for the beach. You had one of your more
traditional breakfasts while reading the paper this morning. The night before
last after Owen and Brennan were to bed the four of you watched Captain
Phillips. Last night you and Carol watched Dustin Hoffman’s Quartet once
again. You watched two people walking from the condo to the beach and head
north. You think they look like your version of Criteria and Renaldo. –
Amorella
0933
hours. Yes. It was an immediate surprise. I thought, ‘There go Criteria and
Renaldo. The two look just as I imagine them, but rather than walk from a condo
in my mind they walked from a real condo on Madeira Beach. Very cool.
You
spent an hour or so in the pool with Kim, Paul, Owen and Brennan. Carol spent
time talking the Mary Lou and reading quietly. You tried a new place for lunch
upon recommendation from condo neighbors, the Sea Breeze Grill about a mile
further north of the Conch Republic on Gulf Boulevard. Linda, Bill and Jen are
stopping by this afternoon. - Amorella
1503
hours. I just saw this. And, here all this time my ‘presences’ have been a
robot. Ha ha!
**
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Wired
Science -
"This Robot
Makes People Experience a Ghostly Presence"
BY Greg Miller
People who’ve
stared death in the face and lived to tell about it—mountain climbers who’ve
made a harrowing descent, say, or survivors of the World Trade Center attacks—sometimes
report that just when their situation seemed impossible, a ghostly presence
appeared. People with schizophrenia and certain types of neurological damage
sometimes report similar experiences, which scientists call, aptly, “feeling of
presence.”
Now a team
of neuroscientists says it has identified a set of brain regions that seems to
be involved in generating this illusion. Better yet, they’ve built a robot that
can cause ordinary people to experience it in the lab.
The team was
led by Olaf Blanke, a neurologist and neuroscientist at the Swiss Federal
Institute of Technology in Lausanne. Blanke has a long-standing interest in
creepy illusions of bodily perception. Studying these bizarre phenomena, he
says, could point to clues about the biology of mental illness and the
mechanisms of human consciousness.
In 2006, for example, Blanke and
colleagues published a paper in Nature that had one of the best titles you’ll ever see
in a scientific journal: “Induction of an illusory shadow person.” In that
study, they stimulated the brain of a young woman who was awaiting brain
surgery for severe epilepsy. Surgeons had implanted electrodes on the surface
of her brain to monitor her seizures, and when the researchers passed a mild
current through the electrodes, stimulating a small region at the intersection
of the temporal and parietal lobes of her brain, she experienced what she
described as a shadowy presence lurking nearby, mimicking her own posture.
The new
study also implicates this region, the so-called temporoparietal junction, as
well as two others. Blanke and colleagues examined 12 people who experienced a
feeling of presence after brain damage resulting from epilepsy, stroke, or
other causes. Like the epilepsy patient in the earlier study, these patients
tended to describe the presence as somewhat menacing, Blanke says. “It’s an
uncanny feeling … that they’re not exactly in danger, but this other presence
doesn’t want anything good.”
Using MRI scans,
the researchers identified three brain regions that were most often damaged in
these patients: the temporoparietal junction, the insula, and the
frontoparietal cortex. All three are thought to play a role in integrating
sensory signals from outside the body (like what you see and hear around you)
with signals from inside the body (like signals from the joints and muscles
that indicate your posture and the position of your limbs).
To see if
they could create the feeling-of-presence illusion in healthy people, the used
what they call a “master-slave robotic system” built by roboticist Giulio
Rognini, who’s also based at the Swiss Federal Institute of Technology in
Lausanne. To interact with the robot, subjects insert an index finger into a
mechanical arm. This arm is the “master” part of the robot. The “slave”
component is another arm located directly behind the subject that mimics the
motion of the master. So, for example, if the subject makes a poking motion,
the robot pokes him or her in the back.
With the
robot in this configuration, subjects reported the strange feeling that they
were poking themselves in the back. But things got even weirder when the
researchers introduced a delay, so that the poke in the back lagged by half a
second. This caused some subjects to feel they were being poked by an invisible
presence lurking behind them. The illusion was generally weaker in the healthy
people than it was in the neurological patients, Blanke says, and some people
were far more susceptible to it than others. The researchers report their findings today in Current Biology.
Here’s
Blanke’s hypothesis about what’s going on: Normally, the parts of the brain
that initiate movements send a signal to sensory regions of the brain to give
them a heads up; But when the robot is in delay mode there’s a disconnect
between the movement signal (initiate poke!) and the sensation (um, not feeling
any poking). It’s a mismatch that almost never happens in real life. The
researchers suggest that the subjects’ brains reconcile this mismatch by
creating the illusion of another presence that’s doing the poking. After all,
something is poking them in the back.
This kind of
sensory-motor mismatch has been proposed previously to explain some of the
symptoms of schizophrenia, most notably by the cognitive neuroscientist Chris
Frith at University College London. For example, it’s very hard for healthy
people to tickle themselves—you don’t experience that funny feeling if you know
what’s coming. But Frith and colleagues have found that people with schizophrenia can tickle themselves, suggesting that they perceive motions that they
themselves have initiated as coming from another source. In a similar way,
people with the disorder might misattribute their own internal speech to an
external agent. It’s no wonder paranoia is so common.
“There’s
convergent evidence that this type of action monitoring is essential for the
sense of self, the sense that we are in charge of our own bodies,” said
neuroscientist Peter Brugger of University Hospital Zurich. Blanke’s new
study is important, Brugger says, because it makes it possible to study an
experience that’s very real to many psychiatric and neurological patients, but
very foreign to everybody else. “It’s a very elegant way to explore something
that other people think is just bizarre and a part of their world we can never
access.”
As to why feeling of presence seems
to be especially common in life-threatening situations, Blanke says he can only
speculate. In some situations, the lack of oxygen might make the illusion more
common, he says. But he also notes that people who are recently widowed often
report feeling the presence of their lost spouse. Clearly there are other
psychological factors that can come into play, he says.
Selected and edited from – http://www.wiredDOTcom/2014/11/robot-ghost/
** **
1518 hours. So I am, Amorella.
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