The hollow mask illusion is a feat of optical witchcraft that tricks your brain into thinking that the inside of a rotating mask is exactly like the outside – a face with protruding features.
The hollow-mask optical illusion is a simple test for the neurological dysfunction associated with schizophrenia. The visual senses of a person with a healthy brain will be overwhelmed by the illusion; a schizophrenic person reliably sees right through it.
What is the hollow-mask illusion? When a hollow mask is turned away from you, it will appear to be facing you; the nose, for example, will appear to be protruding from the mask. The illusion is so powerful that even if a test subject is told in advance what to look for, and even if he watches the illusion unfolding, his senses will still deceive him.
Seeing through the illusion isn’t a completely reliable indicator of schizophrenia. Some alcoholic test subjects may not be fooled by the hollow mask illusion. Being under the influence of cannabis (marijuana) may also yield a false positive.
Article:
http://www.cracked.com/article_22412_6-tiny-things-that-indicate-youve-got-huge-medical-problems.html
http://www.newscientist.com/article/dn16911-schizophrenics-see-through-hollowmask-illusion.html#.VT3B07mdK70
#neuroscience #hollowmaskillusion #schizophrenia
Dammit...it's still protruding!! Chug Chug perhaps some 151 will do the trick? O.o ;)
ReplyDeleteThis one is bogus since the highlighting is designed to enhance the effect. In the real test, with real masks lighting cues help.
ReplyDeleteTook me a little bit to see through it. Pretty cool 3D model!
ReplyDeleteIt is similar to how people of opposite sex tend to appear more attractive, and you can't consciously control the interpretation. Neural circuits that formed in evolution, and are not subject to conscious management... But some are learned, for example, correct movement patterns to ride a bicycle (witchcraft: "Backwards Brain Bicycle" goo.gl/nVvxsC).
ReplyDeleteThis makes me think of the spinning dancer, who for some appears to rotate left and for others right (or even alternate). When you try to reverse an illusion, it certainly is a mental challenge
ReplyDeletePatrick Horgan I just looked at a real mask version of this illusion and it looked identical to me (if somewhat smoother and monochrome) - what highlighting enhancement are you claiming is not legitimate?
ReplyDeleteInteresting that not falling for the illusion gets to be called a symptom of pathology and "testing positive". Some might see an analogy with religious faith there.
ReplyDeleteThere is a study, data (fMRI) and control group (All the participants with schizophrenia could distinguish between the two types of photos, whereas control volunteers without the condition were fooled 99 per cent of the time) - pretty far from religion for me.
ReplyDeleteIn my opinion it's not "not falling for the illusion" but rather brain not functioning in the proper way.... what's explained in both newscientist article and abstract of the linked study.
Very cool. The hint is the apparent change in direction of rotation even as the rotation is consistent.
ReplyDeleteWhich is to say, thorough consideration of the situation must lead to one of two conclusions: either the mask is hollow on one side or else the rotation is changing direction. But the latter is impossible, hence the former must be the case. So mind can deduce the truth ... but eyes, naive of the nature of rotation, cannot. I suspect the schizoid brain has inverted the sensory and inductive faculties to some degree.
ReplyDeleteOlgierd Ziolko What's common with faith in God is that (1) many view it as an illusion and (2) where it is dominant, failure to succumb to it tends to be taken as a cause not to trust the person (example: when did last an avowed atheist get elected POTUS?). Close enough for me:)
ReplyDeleteBoris Borcic oh, sorry sir, I misunderstood you completely (but I still disagree - there's not "where it is dominant" or "where it's perceived", just naked facts).
ReplyDeleteAnd interesting thing you mentioned that: when did last an avowed atheist get elected POTUS - it get me bad thrills regardless of the fact I don't even live in the US (but still US shows interesting way of giving some basic rights for non-christians: http://www.huffingtonpost.com/2014/09/19/satanic-coloring-book_n_5846640.html )
Olgierd Ziolko "just naked facts" are irrelevant if nobody claims them as such... what's IMO the case of almost all "naked facts". Conversely, where there's consensus about it, the difference between an alleged fact and a true fact becomes academic. Whatever, I find the idea of taking this illusion as an analogy for faith intriguing, if only for how it offers to (non-schizophrenic) atheists a model of faith they can inhabit.
ReplyDeleteSean Walker a good example is the highlighting on the nose. It always makes it look like the nose is protruding and catching the light even on the reverse where the nose is supposed to be receding and couldn't possibly have a _high_light.
ReplyDeletePatrick Horgan Funnily enough, the one way I found to control/escape the illusion is to concentrate on the tip of the nose. Nothing else works. The highlight you criticize could pass as translucency of the material, light from above diffusing through.
ReplyDeletePatrick Horgan I saw the same effect with an actual mask being rotated - depends on how they set up the lights I believe.
ReplyDeleteThe chin works too, if I concentrate on the circular motion of either the tip of the nose or that of the chin, I can reliably dispel the illusion.
ReplyDeleteWell, I could, until I said so:)
ReplyDeleteCorina Marinescu Thanks again for your permanent seminar:) Is there any sense that the administration of the test of this illusion requires an amount of subject innocence that would make it inappropriate where the latter can't be assumed? I mean, is there any way to verify the tested don't fake their response/reaction? is the matter of someone being or not subject to the illusion, not purely one of self-reporting?
ReplyDelete> Seeing through the illusion isn’t a completely reliable indicator of schizophrenia. Some alcoholic test subjects may not be fooled by the hollow mask illusion. Being under the influence of cannabis (marijuana) may also yield a false positive.
This kind of spells a legal stake or challenge. Earlier today, I saw news of a pair of graduates devising a roadside test for THC, as if went without saying that where it is otherwise legal, drivers under the influence of THC had to be recorded and punished just like drivers under the influence of ethanol.
According to google-mediated documentation, in contrast to what's the case with drinking I'm sure, extensive statistics fail to show that driving under the influence of weed, by itself alone entails a raise of averaged road fatality risk. What's readily shown is a relative loss of function across much of the board, and a natural hypothesis to explain the paradoxical statistics (if they are real, I didn't really check) is to say the cannabis-influenced on average become more averse to risk in such proportion that it compensates for the relative losses of functions, where the ethanol-influenced on average become less averse to risk, which multiplies the impacts of the relative losses of functions.
The above conclusion (to the effect that is undue to presume smoking marijuana identical to drinking alcohol as far as road security is concerned) -- the above conclusion would seem sufficient but is possibly ill-defended against some sneakily moralistic way legal traditions may evolve to declare it irrelevant.
That's where the case you inform us of, of the substances inducing "false positives" for failure of hollow mask illusion could come into play to shake off an assumption on which to assert the (ipso facto inadequately) applied legal standards premised. These "false positives" are manifest cases of the substances inducing a relevant general sort of gain in function.
Then there's a ready narrative to separate weed from booze. While it may like weed sometimes induce a gain in some functions, with booze that will typically only add to a characteristic overinflation of self-confidence that is the main cause of added risk with moderate DUI (or so will we claim). Weed or cannabis at least appears and can likely be shown to promote tendencies capable to exploit relative gains in function, in ways that reduce overall risks. Maybe even not wholly on average, but part of the overall issue is the freedom to be a secret outlier along dimensions both significant and orthogonal to the central issue -- which is "here," that of road casualties.
Boris Borcic
ReplyDeleteI'm a bit "off" these days, because recently I've lost someone. I try to keep my mind busy by posting here and there and distract myself...but I do not feel like replying to comments or even talk.
Sorry to learn that, Corina Marinescu.
ReplyDeleteMes condoléances.