Post by auntym on Nov 1, 2017 10:58:51 GMT -6
www.newscientist.com/article/dn26516-ever-felt-a-ghostly-presence-now-we-know-why/?utm_campaign=Echobox&utm_medium=Social&utm_source=Twitter&cmpid=SOC|NSNS|2017-Echobox#link_time=1509532068
Ever felt a ghostly presence? Now we know why
Trick of the brain: you are not alone Aaron McCoy/Getty
By Anil Ananthaswamy /
6 November 2014
Ghostly presences – the feeling of someone near you when there’s no one there – could be down to your brain trying to make sense of conflicting information. For the first time, the brain regions involved in such hallucinations have been identified – and a ghost presence induced in healthy people.
The work sheds light on why some people with conditions such as schizophrenia and epilepsy feel an alien presence nearby, and may also explain why mountain climbers often report being accompanied by the presence of what’s called “the third man”.
Read more: Chill factors – The everyday things that make us see ghosts
In 1933, when British explorer Frank Smythe came close to conquering Mount Everest all by himself, he couldn’t shake off the feeling that someone else was climbing with him. But he was alone, having left his team far behind. Smythe was hallucinating. He even broke off a piece of cake and offered it to his invisible climbing partner.
This condition, called feeling of presence (FoP), is different from other bodily hallucinations, such as out-of-body experiences, in which you feel you are outside your body looking at it, or the doppelgänger effect, in which you see and interact with your double. Such hallucinations have a visual component.
Mystical presence
That’s not the case with FoP. “[It’s] more mystical,” says neurologist Olaf Blanke of the Swiss Federal Institute of Technology in Lausanne. “You are convinced that there is something, but you don’t see anything, you don’t hear anything.”
To identify the potential neural mechanisms behind FoP, Blanke’s team first studied 12 people with epilepsy and other sensory-motor problems, all of whom had reported feeling a presence nearby. Their analysis pointed to damage in three brain regions: the temporoparietal junction (TPJ), the insula and the frontal-parietal cortex.
In previous studies, Blanke’s team had linked the TPJ with out-of-body experiences and the insula with the doppelgänger hallucination. Normally, these brain regions integrate sensory signals from outside and inside the body, to create the sense of an embodied self. In out-of-body experiences and other such conditions, the integration of these multisensory signals is compromised, leading to hallucinations.
The new study shows that FoP involves disruptions not just in the integration of external and internal sensations in the TPJ and insula, but also signals related to movement (which are processed in the frontal-parietal cortex).
Armed with this knowledge, Blanke’s team turned to a robot to see if they could use it to disrupt the normal brain processes and induce a feeling of presence.
WATCH VIDEO & CONTINUE READING: www.newscientist.com/article/dn26516-ever-felt-a-ghostly-presence-now-we-know-why/?utm_campaign=Echobox&utm_medium=Social&utm_source=Twitter&cmpid=SOC|NSNS|2017-Echobox#link_time=1509532068
Chill factors: The everyday things that make us see ghosts www.newscientist.com/article/mg23631500-700-chill-factors-the-ingredients-that-make-up-a-haunting/?intcmp=PAC|NSNS|2017-inlinelink_ghostly-presence&utm_medium=PAC&utm_source=NSNS&utm_campaign=inlinelink_ghostly-presence
Ever felt a ghostly presence? Now we know why
Trick of the brain: you are not alone Aaron McCoy/Getty
By Anil Ananthaswamy /
6 November 2014
Ghostly presences – the feeling of someone near you when there’s no one there – could be down to your brain trying to make sense of conflicting information. For the first time, the brain regions involved in such hallucinations have been identified – and a ghost presence induced in healthy people.
The work sheds light on why some people with conditions such as schizophrenia and epilepsy feel an alien presence nearby, and may also explain why mountain climbers often report being accompanied by the presence of what’s called “the third man”.
Read more: Chill factors – The everyday things that make us see ghosts
In 1933, when British explorer Frank Smythe came close to conquering Mount Everest all by himself, he couldn’t shake off the feeling that someone else was climbing with him. But he was alone, having left his team far behind. Smythe was hallucinating. He even broke off a piece of cake and offered it to his invisible climbing partner.
This condition, called feeling of presence (FoP), is different from other bodily hallucinations, such as out-of-body experiences, in which you feel you are outside your body looking at it, or the doppelgänger effect, in which you see and interact with your double. Such hallucinations have a visual component.
Mystical presence
That’s not the case with FoP. “[It’s] more mystical,” says neurologist Olaf Blanke of the Swiss Federal Institute of Technology in Lausanne. “You are convinced that there is something, but you don’t see anything, you don’t hear anything.”
To identify the potential neural mechanisms behind FoP, Blanke’s team first studied 12 people with epilepsy and other sensory-motor problems, all of whom had reported feeling a presence nearby. Their analysis pointed to damage in three brain regions: the temporoparietal junction (TPJ), the insula and the frontal-parietal cortex.
In previous studies, Blanke’s team had linked the TPJ with out-of-body experiences and the insula with the doppelgänger hallucination. Normally, these brain regions integrate sensory signals from outside and inside the body, to create the sense of an embodied self. In out-of-body experiences and other such conditions, the integration of these multisensory signals is compromised, leading to hallucinations.
The new study shows that FoP involves disruptions not just in the integration of external and internal sensations in the TPJ and insula, but also signals related to movement (which are processed in the frontal-parietal cortex).
Armed with this knowledge, Blanke’s team turned to a robot to see if they could use it to disrupt the normal brain processes and induce a feeling of presence.
WATCH VIDEO & CONTINUE READING: www.newscientist.com/article/dn26516-ever-felt-a-ghostly-presence-now-we-know-why/?utm_campaign=Echobox&utm_medium=Social&utm_source=Twitter&cmpid=SOC|NSNS|2017-Echobox#link_time=1509532068
Chill factors: The everyday things that make us see ghosts www.newscientist.com/article/mg23631500-700-chill-factors-the-ingredients-that-make-up-a-haunting/?intcmp=PAC|NSNS|2017-inlinelink_ghostly-presence&utm_medium=PAC&utm_source=NSNS&utm_campaign=inlinelink_ghostly-presence