What do
zombies and androids have in common? They're almost human, but not quite. That
disconnect is creepy, in a way that scientists are searching to understand.
The
uncanny valley is the idea that as a robot's appearance becomes more and more
humanlike, we don't always respond to it more positively. Rather, there's a
point on the scale between robot and human where we are repulsed. If it's
mechanical but not entirely human, a robot seems disturbing.
Why would
that be? It would make sense that as human likeness increases in a robot, so
would our comfort with it. But on a graph showing that relationship, there's a
"valley" where this familiarity dips down into creepiness, and then
comes back up again with more human characteristics.
You may
have experienced feeling this while watching animated movies that incorporate
humanlike forms. It's also the reason that you might get freaked out by clowns
or by photos of people with extreme plastic surgeries who don't look quite real
anymore. Our brains come to an impasse when we see something that resembles a
member of our species but just doesn't make the cut.
Some
animators sidestep the issue: in the movie "WALL-E," for example, the
main character has eyes but is not very humanlike otherwise; he is clearly a
robot. His friend, EVE, looks like a white shape with eyes. Both express
emotions clearly but don't try to mimic the human shape or form.
And HAL 9000
from "2001: A Space Odyssey" is just a red camera eye, but it too
conveys feelings.
But when
you get more humanlike, things get weird. Some reviewers were put off by
the characters in the film "Polar Express," for instance.
Then
there are the Na'vi in "Avatar," who have many physical human
characteristics in addition to morphed features and tails. But they are also
blue, creating a sense of "otherness" that may have made them less
distasteful to viewers -- in other words, they were sufficiently un-human.
Ayse
Saygin, professor at the University of California, San Diego, is using
cutting-edge brain science to understand this strange quirk of human nature.
Although the idea of the uncanny valley has been observed, there has not been
much rigorous scientific experimental work on it, partly because it's hard to
get at the heart of the matter objectively.
"Even
if we don't actually define it in words, we may be able to find signals for it
in the brain," Saygin said.
Saygin
and colleagues published a study last year using functional magnetic resonance
imagining (fMRI), looking at what's happening in the brain that might explain
the uncanny valley phenomenon.
They hypothesized that, at least in part, the
effect might result from a violation of the brain's predictions. When we
anticipate one thing but see another, we get an error, and that error makes us
shy away from the thing we're viewing.
The
researchers showed 20 participants some video clips of three "actors"
moving in the same ways: a human, an android modeled after the human, and a
stripped-down robot (the same android without its humanlike form). Although
this is a small sample of people, it is typical for neuroimaging studies, which
are expensive and time-intensive.
Something
interesting emerged in the results: "The network that normally processes
your body movements is more active when you view an android," compared
with when you look at a stripped-down robot or a human, Saygin explains.
This
could be because the brain has to combine conflicting information, she said.
"Your
brain's gonna be like, 'Hey, wait a minute, you told me this was a human, and
now this area told me that this is not moving like a human. So, I have to
really compute that,' " she said. "That's what we think the uncanny
valley might be partially caused by, and we have seen some brain activity that
looks like that."
The
uncanny valley phenomenon was put forth in an article in
"Energy" in 1970 by Japanese robotics expert Masahiro
Mori. But before that, Ernst Jentsch wrote about "the uncanny" in a
1906 essay, and Sigmund Freud followed up 13 years later.
Yet the
idea is largely based on anecdotes, and researchers such as Karl MacDorman,
associate professor of human-computer interaction at Indiana University, are
working on experiments to hone in on possible explanations. MacDorman briefly
worked with Saygin in Japan.
In his
view, the uncanny valley effect has to do with a mismatch in features of a
single animation or robot, with some parts appearing much more humanlike than others.
For instance, when a very human-looking head is placed on an obviously
mechanical body, that can be creepy. So can a human face with robotic eyes.
"When
there are elements that are both human or nonhuman, this mismatch can produce
an eerie sensation in the brain," MacDorman said. "It's when
different parts of the brain are coming to different conclusions at the same
time."There are
other factors that may play in, however.
The
uncanny valley effect could have to do with uncertainty about whether a robotic
character is truly alive or dead, and even play into our deep-seated fears of
death. Alternatively, it may be part of cognitive dissonance, which happens
when a person's beliefs are not in line with their behaviors -- for instance, a
smoker who berates other smokers.
From an
evolutionary perspective, humans have developed an aversion to sickness, and a
creepy-looking almost-human might tap into our internal system that warns us
against sources of disease. In relation, we evolved to choose mates who are
healthy, and weird robots may set off the same warning bells that told our
ancestors to stay away from unfit sexual partners.
MacDorman's
current focus is on the uncanny valley with respect to empathy: that is, is the
uncanny valley phenomenon related to a person's difficulty in identifying with
particular computer-animated or robotic characters in films? Does it relate to
the impression that these characters are somehow "soulless," and in
what ways?
Saygin's
ongoing studies make use of electroencephalography, or EEG, which measures
electrical activity along the scalp. While fMRI tells where in the brain
activity occurs, EEG is better for looking at when -- that is, when in viewing
agents with different degrees of humanness do people's brain patterns change.
EEG is also much more portable and less expensive. Rather than a big scanner,
it involves a cap worn on a person's head.
Researchers
may be able to understand the EEG patterns associated with the uncanny valley
effect, and people's comfort with various robotic forms. Eventually, this
information could be used to help robot developers or animators who don't want
their creations to scare people.
"Instead
of asking somebody, 'Do you like this robot?' we could get that information a
lot more directly, and faster perhaps, if we can develop these
technologies," she said.
Have
you ever experienced the uncanny valley effect? Share your thoughts in the
comments.
