--- In FairfieldLife@yahoogroups.com, turquoiseb <no_reply@...> wrote: > > cf. http://tinyurl.com/lah5w7c <http://tinyurl.com/lah5w7c> > > :-)
We still need a customers review for this one. Anyone? > > --- In FairfieldLife@yahoogroups.com, "salyavin808" wrote: > > > > Delusional People See the World Through Their Mind's Eye > > > > A mechanism for how the brain creates and maintains delusions is > > revealed in a new study. > > > > Having delusions, such as a belief in telekinesis, can influence how > > people see the world - literally. > > > > Human beliefs > > > ic.html> are shaped by perception, but the new research suggests > > delusions unfounded but tightly held beliefs can turn the > > tables and actually shape perception. People who are prone to forming > > delusions may not correctly distinguish among different sensory > inputs, > > and may rely on these delusions to help make sense of the world, the > > study finds. Typical delusions include paranoid ideas or inflated > ideas > > about oneself. > > > > "Beliefs form in order to minimize our surprise about the world," said > > neuroscientist Phil Corlett of Yale University in New Haven, Conn., > who > > was not involved in the study. "Our expectations override what we > > actually see," Corlett added. > > > > The prevailing thinking holds that people develop delusions > > > > to predict how events in their lives will occur just as > > Pavlov's dog learned to predict that the sound of a bell ringing meant > > dinnertime was imminent. Humans update their beliefs when what they > > predict doesn't match what they actually experience, Corlett said. > > > > But delusions often appear to override the evidence of the senses. To > > test this idea, German and Swedish researchers conducted behavioral > and > > neuroimaging experiments on healthy people who harbor delusions. > > > > In one experiment, volunteers were given a questionnaire designed to > > measure delusional beliefs. Questions included: Do you ever feel as if > > people are > > reading your mind?; Do you ever feel as if there is a conspiracy > against > > you > > ?; Do you ever feel as if you are, or destined to be someone very > > important?; and Are you often worried that your partner may be > > unfaithful? > > > > The participants then performed a task that tested their visual > > perception: They were shown a sphere-shaped set of dots rotating in an > > ambiguous direction, and asked to report which direction it was > rotating > > at various intervals. > > > > People who harbored a greater number of delusional beliefs (those who > > scored higher on the questionnaire) saw the dots appear to change > > direction more often than the average person. The result confirms > > findings from previous studies that delusional individuals have less > > stable perceptions of the world. > > > > In a second experiment, the volunteers were given glasses, which they > > were told would bias their view so that the rotating dots would appear > > to go in one direction > > more > > often than the other direction a delusion, because these were > > actually ordinary glasses. The volunteers performed a similar > > dot-watching task, with a learning phase and a test phase. During the > > learning phase, the dots clearly rotated in one direction, but during > > the test phase, the direction was ambiguous. > > > > While wearing the glasses, the volunteers reported seeing the dots > > rotate in the biased direction, even during the test phase. They clung > > to the delusion that the glasses altered their vision, even though the > > visual evidence contradicted this idea, suggesting they used their > > delusional beliefs to interpret what they were seeing. > > > > A third experiment was similar to the second, but brain scans were > taken > > using functional magnetic resonance imaging. The scans showed that > when > > people were deluded about the direction of the dots' rotation, their > > brains were encoding the delusion as if they had really seen the dots > > move that way. In other words, people weren't just ignoring what they > > saw; they were really seeing something else. > > > > Furthermore, the brain scans revealed connections between a brain area > > involved in beliefs, the orbitofrontal cortex, and an area involved in > > visual processing, the visual cortex. (Both became active during the > > delusional observations.) > > > > Corlett finds the results exciting. The study "gives us a nice > > explanation for the relation between belief and perception and how it > > might go awry," he said. > > > > But he cautioned that drawing inferences about people who are > clinically > > delusional, such as those with schizophrenia > > > on-distortion.html> , may be premature. Time will tell whether the > same > > brain mechanisms are at play for these patients, he said. > > > > http://www.livescience.com/39038-how-delusions-shape-perception.html > > > > >
