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Seeing Things That Aren't There? That's Just Your Brain Functioning Normally
"Pay attention to that alley over there. A gorilla in a clown suit is going to come out of it in a second." If I said that to you, and the ape subsequently appeared, you would (rightly) conclude that I'd helped you see the beast by focussing your attention on the right place at the right time. Suppose, though, that I'd said to look at the alley after the gorilla rushed by. And then you realized, hey, I saw a gorilla over there! That would be weird right? After all, if awareness is a straightforward record of what we've seen, then you either see the gorilla or you miss it. Outside of dreams, there's not supposed to be "miss the gorilla, look where it was, then change the record to say that you saw it." But, this paper suggests, intuition is wrong, and this dreamlike revising is indeed a part of everyday waking perception. In other words, it isn't always seeing a gorilla that makes you focus on the alley. Sometimes, focussing on the alley makes you see the gorilla.
In the study, published last month in the journal Current Biology, Claire Sergent and her colleagues had 18 volunteers look at a computer screen on which were two circles. After a moment, one of the two circles filled with fuzzy parallel lines for a mere 20th of a second. The volunteers then had to say which circle contained the lines and how they were oriented (vertical, horizontal or various kinds of diagonal). People's ability to answer correctly was much enhanced if they had a cue—if the correct circle dimmed a bit just before the lines appeared—thus drawing their attention.
Remarkably, though, people also did better on the task if the relevant circle dimmed about a half second after the lines had appeared. As Sergent et al. write, "this suggests that, contrary to a commonly held assumption, postcueing can influence perception itself."
You might think that this cueing effect was a sort of hallucination—that people could have imagined lines only because, and wherever, they'd seen the circle dim. But Sergent et al. eliminated that possibility by dimming both circles in one set of tests. In this case, people still saw the lines in the place where they had really appeared before the cue. They weren't following the cue alone to imagine something wherever it appeared; rather, the focussing device was leading them to see something that really had appeared—but which was no longer visible when they realized they had seen it.
There has been a lot of research over the years on perceptions that never reach awareness. For example, people whose visual cortex is damaged are unaware of seeing anything, yet they often react to things in their field of vision. Sergent et al.'s study is significant because it's not about these kinds of perceptions outside of consciousness. Instead, it's a demonstration that the mind can edit perceptions before they reach consciousness. Therefore Sergent et al. also had to eliminate the possibility that these results were a kind of blindsight, in which people were giving correct answers without knowing how or what they knew.
To address this, the researchers ran the experiment on another 18 people, and this time, added a measure of their awareness: in addition to saying where the lines were and how they were oriented, volunteers also had to rate how visible they were. There was a certain amount of projection, or "response bias," here, with people reporting better visibility wherever there was a cue (even when no actual lines had appeared). Despite that noise, though, there were "drastic improvements" the reported visibility of lines that had appeared and vanished just before the attention-focussing cues. In other words, post-event cues weren't just causing people to see lines in the right places; those cues were also causing people to know that they'd seen something. Which suggests that the reality you see around you isn't a "raw feed" of data coming from the eyes and visual centers of the brain, but a product that has been edited—and (as Dan Dennett points out here) is still being edited, by "you," even as "you" consume it.
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Sergent, C., Wyart, V., Babo-Rebelo, M., Cohen, L., Naccache, L., & Tallon-Baudry, C. (2013). Cueing Attention after the Stimulus Is Gone Can Retrospectively Trigger Conscious Perception Current Biology, 23 (2), 150-155 DOI: 10.1016/j.cub.2012.11.047
The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.
- In Italy, a team of scientists is using a highly sophisticated detector to hunt for dark matter.
- The team observed an ultra-rare particle interaction that reveals the half-life of a xenon-124 atom to be 18 sextillion years.
- The half-life of a process is how long it takes for half of the radioactive nuclei present in a sample to decay.
A study looks at the ingredients of a good scare.
Catching fear in a bottle<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzg1Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyOTQwMTcyMn0.WtpJ1E_dhK2o09fBpKARynj4_p5NXeklgsXsbd7xr9w/img.jpg?width=980" id="8ff51" class="rm-shortcode" data-rm-shortcode-id="f10dd9188b173f4a36e85e9325507c6b" data-rm-shortcode-name="rebelmouse-image" />
Credit: Photo Boards/Unsplash<p>Previous studies have tracked physiological signs of fear arousal, but none have established a one-to-one correlation between that arousal and specific, actual fear events.</p><p>Andersen says that much of the research has been conducted in lab settings with weak fear stimuli, observing subjects as they experience things like scary videos. Scares in these situations tend to be weak and difficult to measure. Even harder to track in these situations is the link between enjoyment and fear. </p>
Eyes everywhere<iframe src="https://player.vimeo.com/video/109695164" width="100%" height="480" frameborder="0" scrolling="no" class="rm-shortcode" data-rm-shortcode-id="267ba87cfb8591ed5830499574d2272a"></iframe><p>Andersen and his colleagues conducted their experiments at <a href="https://dystopia.dk" target="_blank" rel="noopener noreferrer">Dystopia</a> Haunted House, a commercial attraction in Vejle, Denmark constructed in an old, run-down factory. The Recreational Fear Lab has a long-standing partnership with the spook shack.</p><p>They outfitted 100 volunteers with heart monitors and sent them on their terrifying way through the 50-room horror mansion. The facility incorporates a number of fright mechanisms including frequent jump scares in which a sudden threat takes a visitor by surprise.</p><p>Researchers surreptitiously observed their participants on closed-circuit video as they made their way through the attraction. They tracked each individual's scares, scoring them for intensity according to their visible reactions. After exiting the attraction, individuals self-reported their experiences in the haunted house.</p><p>Combining these self-reports with observer notes and each participant's heart-rate data gave the researchers subjective, behavioral, and physiological insights into the ways in which fear is experienced, and when it's a good thing or not.</p>
A pair of inverted U-shapes<p>In analyzing their data, the researchers saw two separate inverted u-shape curves. One depicted participants' enjoyment based on their self-reports and observed behavior. A similar u-curve was detected in their heart rates showing that just the right amount of heartbeat acceleration is associated with fun, but too much is too much. It's the terror Goldilocks zone.</p><p>Says Andersen, "If people are not very scared, they do not enjoy the attraction as much, and the same happens if they are too scared. Instead, it seems to be the case that a 'just-right' amount of fear is central for maximizing enjoyment."</p><p>The research suggests that being scared is enjoyable when it represents just a quick minor physiological deviation from one's normal state. When it goes on too long, however, or triggers too severe a physiological change, it becomes disturbing. Game over.</p><p>Andersen notes that this is not dissimilar to the factors known to make interpersonal play enjoyable: just the right amount of uncertainty and surprise. These are, maybe not coincidentally, also the ingredients of a successful joke.</p>
A meteorite that smashed into a frozen lake in Michigan may explain the origins of life on Earth, finds study.
- A new paper reveals a meteorite that crashed in Michigan in 2018 contained organic matter.
- The findings support the panspermia theory and could explain the origins of life on Earth.
- The organic compounds on the meteorite were well-preserved.
Meteor streaks through Michigan sky<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="80b7f30820153b35fc515592d7475f53"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/EPu2qnqMYBo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The meteorite that smashed into Strawberry Lake carried pristine extraterrestrial organic compounds.
Credit: Field Museum