I am currently working as a TA for the Summer Science
Program (SSP) which takes high school students that have been bored with their
regular class work and show exceptional interest and talent in math or science
and gives them five and a half weeks of lectures in astronomy, physics,
computer science, and calculus, alongside a project to track and determine the
orbit of a near Earth asteroid. All of
the TAs are allowed to give a guest lecture during the program. I decided to do mine on a few of the ways our
brains trick us. This post will focus on
pareidolia, with the other examples from my lecture to follow in later
posts. Some of the larger effects that I
draw out from individual phenomena are actually the result of multiple
psychological and biological factors working together. I have still included them as examples because
they are at least partially caused by the brain trick I am exploring. There are too many logical fallacies and
human biases to cover all of them in a 50 minute lecture.
While I have not done any original research on this topic
(yet!), I’ve found that I am very interested in skepticism and critical
thinking and what happens when we have a lack thereof. The
scientific method has critical thinking built into it. It mandates that we must make our hypotheses
before we see our data and that we use the rules of statistics and probability
to interpret our data. Common practices
such as double-blinded studies help minimize the effect human biases have on
experimental results. But what happens
once we leave the laboratory? Surely our
brains don’t stop being biased. They
don’t stop interpreting things subjectively.
How are they tricking us when we stop paying attention?
One example of our brains tricking us is “pareidolia,” the
phenomenon of seeing patterns in random noise.
Our brains are excellent at pattern recognition, and, generally, this is
a good thing. It lets us learn
languages, play music, do science and math, make art, and develop social
skills. But our brains overdo it. They see patterns where ever they can. This may be a leftover evolutionary
trait. Back when we still had to worry
about being eaten, if you heard a rustle in the tall savanna grass, you had
better recognize the pattern that the last time and the time before that, a
rustle in the grass meant there was a lion and you’d better run. It is much better to accept a false positive
in this case (I run away because I think there is a lion, but it was really
just the wind rustling the grass) than a false negative (I stay because I
figure it’s just the wind and end up being eaten by a lion). So extending this grass rustling/lion pattern
makes sense.
Recognizing facial expression patterns is also very
important. If you want to get along with
the people in your group, you have to know if they’re upset with you or happy
or worried. So our brains love to see
faces. They are looking for any piece of
information that will tell them what is going on, if there is any danger, if
anybody looks like they are angry.
That’s why when faced with pure random noise, our brains try so hard to
find a clue about what is going on, and they start to see things that aren’t really
there. Bam! Pareidolia.
What this leads to in the wider scheme of things is cultural
beliefs in things like Bigfoot, aliens, and ghosts. One famous example of pareidolia is the “Face
on Mars.”
(Image from Wikipedia)
In 1976, the spacecraft Viking I took
an image of a Martian rock outcropping that resembles a face. Some people interpret this as evidence for
intelligent life on Mars. Others might
recognize that seeing such a pattern in Martian rocks is just a result of
pareidolia and our brains’ tendency to see faces when none are there.
More recently, the Mars rover, Spirit, took an image of a
Martian rock formation that resembles a large, hairy, upright walking ape.
(Image from abclocal.go.com)
This is claimed to be evidence of Bigfoot on
Mars. Such patterns tend to disappear once images are taken with better equipment or from a different angle. When the Face on Mars was imaged again in 2001 by the Mars Global Surveyor, it's facial features are no longer visible.
(Image from http://www.msss.com/)
Interesting.
There is also auditory pareidolia. Our brains gather information from the sounds
around us, so they are also expecting auditory patterns. This leads to exciting results such as
listening to clips from skeptoid.com of arbitrary sine waves which sound like nothing at first…
But once we are given a suggestion of what could be there…
But once we are given a suggestion of what could be there…
And listen to the original clip again…
We start to hear patterns, intelligible speech, that wasn’t
there before. All our brains need is a
little bit of a clue as to what we might be hearing in that random bit of noise
and that’s enough for them to latch on to a pattern. Our brains will take any bit of information
they can get to make sense of the world around us, even if it means constructing
an artificially ordered world.
But now that you know it happens, you can take care not to
fall into the same trap. Just as you
wouldn’t think that because a cloud is in the shape of a bunny rabbit, it is
actually a bunny rabbit, you need not think that because there appears to be
what looks like Bigfoot on Mars, it is actually Bigfoot on Mars. And not all
rock musicians have secret messages to Satan that can be revealed by playing
their songs backward.
But sometimes Darth Vader really is on your toast:
(Image from coolest-gadgets.com)
