
A Magician Explains Why We See What’s Not There - dnetesn
http://nautil.us/issue/70/variables/a-magician-explains-why-we-see-whats-not-there
======
csmeder
In the field of UX/Psychology there is a term “suffice”. Our brains are
constantly sufficing rather that perceiving all data and interpretating it. If
we had to do the latter end of the spectrum, our heads would need to be
bigger, to the point birth wouldn’t be possible based on current female
autonomy. You wouldn’t have survived child birth.

As a result when a person visits a page on a website for the first time people
in average scan the page only reading a few words (I’ve hear 7 on average
claimed). However, most beginner designers will not realize this and put a
couple hundred words on a page with out proper typographic hierarchy. Better
designers (same is true for poster designers) use typography and visual
hierarchy (Font sizing, spacing/white-space, color, font weight, alignment) to
create a design that is easy to scan for a sufficing human brain.

The less scannable the page is the more the brain needs to work to make sense
of what is being displayed (higher cognitive load), and the less of a chance
the user will read the highest priority data first (the context or hook data).

If the user reads the data in the wrong order, it will likely be confusing
noise. The goal of a designer is to present the data in such a way that the
signal to nose ratio is high, as they scan and dig deeper into a presented
page or poster.

~~~
pier25
I've always said that the most important job of a UI designer (or graphic
designer in the case of posters) is how you communicate with your users.

Unfortunately it's too common that people, specially designers, put aesthetics
first.

To put it bluntly, users don't care about the drop shadow of a button if they
can't find the damn button or if they don't understand in advance what the
button will do.

~~~
DINKDINK
>the most important job of a UI designer [...] is how you communicate with
your users.

>[...] it's too common that people [...] put aesthetics first.

While aesthetics don't need to come first in a design, they do allow a large
amount of information -- that you're trying to communicate -- to be encoded in
a way that's processed subconsciously and quickly:

A stranger dressed in "war paint" approaches you to sell you a coffee is going
to perform worse than a Nanny wearing a warm, fuzzy, cozy, looking sweater.

~~~
eridius
Dressing in "war paint" vs dressing in a sweater is a form of communication.

------
have_faith
The next stage from this is how a spectator remembers a magic trick later on.
Good magicians work backwards from this understanding in designing an act or
trick. "He put the card in the middle of the deck, and it appeared in his
pocket". This is about as granular as the average spectator remembers a magic
trick only minutes or even seconds later. It says a lot about how lossy our
memory really is even when we are concentrating our hardest. Maybe counter
intuitively the harder someone looks the easier it is to direct their
attention.

I would recommend anyone learn a simple magic trick or two, if only to help
you design your products better. All of the information you learn about how
people move through the phases of a trick seem transferable to lots of
disciplines.

~~~
klenwell
On this topic, one of my favorite HN comments compares magic tricks to hacking
someone's brain:

 _Magic tricks are hacking! You are hacking someone 's mind, particularly
their assumptions and attention. The exploits to human psychology and
attention are just as sure as the exploits to crack or unlock a smartphone and
many other software exploits. The difference is that software can be patched
but the evolved behaviors that are the root of the exploits used by magicians
are very hard to "patch"..._

Full comment:
[https://news.ycombinator.com/item?id=4992826](https://news.ycombinator.com/item?id=4992826)

~~~
YinglingLight
Now replace the word 'Magic tricks' with 'Persuasion'

------
bobosha
The neuroscience explanation for this is "Predictive coding". These talks are
fascinating.

related:

[https://www.youtube.com/watch?v=CvAbPtbjxhw&t=1135s](https://www.youtube.com/watch?v=CvAbPtbjxhw&t=1135s)

[https://www.youtube.com/watch?v=P0yVuoATjzs](https://www.youtube.com/watch?v=P0yVuoATjzs)

~~~
bobbiechen
Cool videos!

A nice written introduction to the topic of predictive coding is Scott
Alexander's book review of "Surfing Uncertainty" by Andy Clark:
[https://slatestarcodex.com/2017/09/05/book-review-surfing-
un...](https://slatestarcodex.com/2017/09/05/book-review-surfing-uncertainty/)

~~~
skosch
I have found that book to be an impressive example of poor scientific writing
– one long, convoluted, intentionally obtuse sentence after another, as if the
author was constantly trying to make the reader feel like an idiot.

I have found some more technical articles (e.g. [0]) very useful, but if
anyone knows of a comprehensive introduction that takes more of an
experimental psychology angle, similar to Surfing Uncertainty but less
frustrating, I definitely want to know about it.

[0]
[https://www.sciencedirect.com/science/article/pii/S002224961...](https://www.sciencedirect.com/science/article/pii/S0022249615000759)

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tyingq
_" simply looking at the ball. This, however, was not the case: Although they
looked at the ball once it had been thrown in the air, they spent a lot of
time looking at my face, particularly before the ball reached the top of the
screen."_

I wonder if self driving car tech thinks about this kind of thing. How often,
for example, at intersections, we look at the faces of other drivers and
pedestrians for context.

It's interesting to me both as data for the self driving car, and the obvious
lack of data for human drivers looking at a self driving car.

~~~
fjfaase
It is my experience that I often know what a driver before me is going to do
even before they have started to do so. Probably because I pick up very small
changes in their behavior, as like reducing their speed a little, even before
I have become conscious of them doing so. In theory you could train a neural
network to do the same, but it would probably require a neural network much
larger than the 'electronic' ones that are being used. I guess our
'biological' neural networks are still much more efficient, energy and size
wise, than there 'electronic' versions.

~~~
InitialLastName
I'm not saying it is, and I'm not saying it isn't, and I definitely have felt
the same thing, but it seems to me that the sensation you're calling out is
very susceptible to both confirmation bias and post-hoc reasoning. For
example, I'm sure your brain fires harder when your "expectation" is met than
when it isn't or in all those situations where you just don't make a distinct
prediction.

------
empath75
I got bored a couple of years ago and decided to start learning some magic.

If anyone wants to learn card magic, there are an unbelievable amount of
tutorials on YouTube.

All you need to do some very impressive tricks is a single move — the double
lift.

~~~
tobr
> All you need to do some very impressive tricks is a single move — the double
> lift.

As someone who has had a casual interest in card magic and sleight of hand,
here’s an observation about how so many different tricks can come out of such
a seemingly simple sleight.

There’s a fairly simple formula that makes it possible to be very creative and
come up with endless new tricks and variations.

At the heart of any trick is some sleight, such as the double lift, where the
illusionist creates a seemingly trivial rift between reality as the audience
perceives it, and reality as it actually is.

The illusionist can then get creative with what to do with this difference.

Usually you maintain the facade and do things that would be possible in both
realities. From the audience’s point of view, it’s like the trick hasn’t
started, when in a sense it is already over. Then, at a safe distance from the
original sleight of hand, in terms of time and attention, the illusionist can
now seem to break the rules of the reality the audience believes in, simply by
revealing the difference between the two realities.

This allows you to amplify an underwhelming “Ok, so I couldn’t see that you
picked up two cards” to a very impressive “Wow, my card magically reappeared
at the top of the deck after you put it into the middle of the deck and let me
shuffle it”.

~~~
reitanqild
Really nice explanation, I kind of knew the idea in practice, but can't
remember having seen it so well explained before!

Here's a thing I still wonder about:

I used to practice forcing, so I get the general idea. What I used to do was
mind-reading etc, but there's one particular event that stands out for me,
here is what I think I saw:

A pro magician shows up in a birthday party showing a deck of cards, asks the
host to _think_ of a card, shuffles the deck and shows the card, confirming
with the host that it is correct, then goes on to do all kinds of amazing
tricks where this card shows up again and again.

In my mind, there are only a few options here:

\- they agreed on it (too risky. This bloke does _big_ jobs, won't do that in
an ordinary birthday.)

\- somehow influenced the host ahead of the selection process (how? when? Is
this _actually_ possible with NLP or something? Something about the setup of
the deck?)

\- maybe he tricked us into thinking he had a full deck and all there ever was
was 4 of clubs? (Sounds crazy, bit not impossible for a guy who'll pickpocket
the craziest things, walk around with a flying piece of furniture while
exposed to 180 degrees of audience, non staff on the stage and a TV crew
filming.)

\- somehow guessed it based on eye movements (what I used to _tell_ when I did
stupid "mind reading" tricks that was only stupid forces)

\- somehow tricked the host into thinking this was the chosen card even if it
was another (again how?)

Anyone wants to share pointers? A few words, links to books, web sites,
anything?

~~~
dkersten
How many times did you see this magician perform? If just the once, then it’s
also possible that the magician just lucked out. I know of magicians who will
always ask an audience member to think of a card as the first thing, just in
case they happen to pick the card that the magician knows is the top card (by
briefly peeking or by having it set up). If it is, then the magician looks
amazing. If not, then the magician performs another trick instead and the
audience is non the wiser.

I don’t know how what you described was performed, but I know that magicians
often leave themselves multiple outs in case the audience doesn’t do what they
want them to.

------
darkerside
[https://www.youtube.com/watch?v=6YIPtJlCbIA](https://www.youtube.com/watch?v=6YIPtJlCbIA)

Here's the hollow mask illusion, one of the most fascinating parts of the
article for me.

~~~
eridius
My favorite part of that is the fact that the perception of the hollow mask
rotates in the opposite direction as the actual hollow mask does.

------
wdutch
> What this shows is that participants used my face to predict where I would
> throw the ball

Being someone who likes to avoid eye contact, this explains why when I'm
walking I always end up doing the get-past-you shuffle.

~~~
asadjb
I had; and to a certain degree, still have this issue.

But I got my rate of doing the "get-past-you shuffle" down quite a bit after
learning a simple trick.

While I avoid eye contact, most people do not. Most people, when they see an
on-coming person, judge which side (left/right) to pass them by looking at
their gaze.

The trick is to look in the direction you want to pass the other person in. So
if you're going to take the left side, look to your left.

Most people will then pass you on your right side.

~~~
feintruled
Another good technique is to commit to avoidance early, and stick to it. For
example, when you notice the collision course, start bearing left immediately
- the other person may have started to move in that direction, which would
normally start the 'shuffle' as you both shift to your right, but you short-
circuit that by not reciprocating - keep left. Seems like it might be rude,
but in practice it doesn't seem so, the relief outweighs any ill feeling (or
so I imagine!)

~~~
kqr
Another is to just stop, stand still, and wait for the other person to solve
the situation. I've realized how terrible I am at dealing with those
situations so that's what I've started to do.

------
falsedan
> _One of my other truly astonishing skills involves throwing a ball one meter
> into the air and catching it._

A true miracle of coordinated tracking, movement, and prediction. I'm
delighted to see such a seemingly-trivial thing called out as the remarkable
feat it is.

If you feel it is quite mundane, consider how much work it would be to
automate.

------
cr0sh
He mentions people looking at his face to aid in predicting what the ball's
trajectory will be.

I wonder what eye tracking data from those with high-functioning autism (or
whatever they call what we used to call Aspergers) would reveal, since "face
blindness" and the inability to interpret facial expressions are typical
hallmarks in those individuals?

That is, do such individuals experience a degradation in coordination in such
tasks, and/or related tasks, due to such inabilities?

Or do they make up for it in other ways?

~~~
syn0byte
The example of Agnosia cited in the article indicates that there wouldn't be
any degradation. Proprioception and physical interaction seem to have their
own dedicated pathway.

If not being able to tell vertical from horizontal didn't affect the patient's
ability to interact with the world, why would not being able to tell if a face
is "happy" or "sad" have an impact?

------
blancheneige
This reminds me of an old legend (probably made up but what do I know) that
when early European explorers first reached North America, some native
American tribes, then settled on the shore, were unable to see the ships
coming on the horizon, until one of their shamans pointed at them, because
only they had the necessary conditioning and open mindedness to perceive and
anticipate things that were unfathomable to others.

~~~
krapp
I'm 100% certain that didn't happen, and /r/askhistorians seems to agree[0].
Humans just don't work that way.

[0][https://old.reddit.com/r/AskHistorians/comments/3lh0kz/is_it...](https://old.reddit.com/r/AskHistorians/comments/3lh0kz/is_it_true_that_when_the_indians_saw_ships_for/)

~~~
blancheneige
Thanks for the link. Sounded a bit hard to believe indeed (although if it
_were_ true it would more likely come from Native American folklore rather
than the other side, for I can hardly imagine how they'd be able to recollect
that story from their viewpoint).

------
winchling
We don't really 'see' things. Rather our eyes are just one of the means by
which we correct our _guesses_ about what's out there.

------
PavlikPaja
One must always marvel at the mental gymnastics neurotypical people go to to
explain why their hallucinations are actually a good thing.

~~~
wlib
Implying that said hallucinations, tailored by evolution, are actually a bad
thing.

~~~
PavlikPaja
People outside the WEIRD (Western, Educated, Industrialized, Rich, Democratic)
populations don't experience them. They are not shaped by evolution, but
likely by the excess iron in western food that gets into the brain and shifts
the brain chemistry towards a psychosis like state. (you can look up studies
on rats, or I can look up some if you want)

People who are immune to it have Asperger's or something similar "on the
spectrum".

Anyway, here is one:
[https://www.ncbi.nlm.nih.gov/pubmed/6138953](https://www.ncbi.nlm.nih.gov/pubmed/6138953)

~~~
mrunkel
I'm totally shocked that a wacky theory proponent (complete with zany
acronym!) would link an article talking about iron deficiency to promote their
wacky theory that excess iron causes a psychosis like state.

~~~
PavlikPaja
That acronym is well established in psychology.

