Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Article  Is this real life or is it just fantasy?

C C Offline

INTRO: Those aren’t just lyrics from the Queen song “Bohemian Rhapsody.” They’re also the questions that the brain must constantly answer while processing streams of visual signals from the eyes and purely mental pictures bubbling out of the imagination. Brain scan studies have repeatedly found that seeing something and imagining it evoke highly similar patterns of neural activity. Yet for most of us, the subjective experiences they produce are very different.

“I can look outside my window right now, and if I want to, I can imagine a unicorn walking down the street,” said Thomas Naselaris, an associate professor at the University of Minnesota. The street would seem real and the unicorn would not. “It’s very clear to me,” he said. The knowledge that unicorns are mythical barely plays into that: A simple imaginary white horse would seem just as unreal.

So “why are we not constantly hallucinating?” asked Nadine Dijkstra, a postdoctoral fellow at University College London. A study she led, recently published in Nature Communications, provides an intriguing answer: The brain evaluates the images it is processing against a “reality threshold.” If the signal passes the threshold, the brain thinks it’s real; if it doesn’t, the brain thinks it’s imagined.

Such a system works well most of the time because imagined signals are typically weak. But if an imagined signal is strong enough to cross the threshold, the brain takes it for reality.

Although the brain is very competent at assessing the images in our minds, it appears that “this kind of reality checking is a serious struggle,” said Lars Muckli, a professor of visual and cognitive neurosciences at the University of Glasgow. The new findings raise questions about whether variations or alterations in this system could lead to hallucinations, invasive thoughts or even dreaming.

“They’ve done a great job, in my opinion, of taking an issue that philosophers have been debating about for centuries and defining models with predictable outcomes and testing them,” Naselaris said... (MORE - details)
Magical Realist Offline
Quote:“Underneath our skull, everything is made up,” Muckli said. “We entirely construct the world, in its richness and detail and color and sound and content and excitement. … It is created by our neurons.”

That means one person’s reality is going to be different from another person’s, Dijkstra said: “The line between imagination and reality is just not so solid.”

Actual perception is always updating itself in terms of what images of its environment it is creating. The ability to move around and see objects change in their perspective is one confirmation method it probably relies on. Imaginary images generally remain in place and nonperspectival relative to the moving body.

Possibly Related Threads…
Thread Author Replies Views Last Post
  Is a hole a real thing, or just a place where something isn’t? C C 9 2,032 Jul 3, 2018 04:13 AM
Last Post: Zinjanthropos

Users browsing this thread: 1 Guest(s)