Social: Why Our Brains Are Wired to Connect (26 page)

More recent data focused on children with autism, rather than adults, has suggested a dramatically different relationship between the amygdala and autism.
Children with autism actually have
larger
amygdalae
than typically developing children.
This has been seen in children as young as two to four years old
and in children up to age twelve.
This is a long time to be walking around with an enlarged mechanism for socioemotional sensitivity, and it is enlarged during one of the most critical socialization periods of our lives.

When we read that a brain region is larger in one group than in another, we assume it must be doing more of whatever it does.
Seeing that Einstein had an abnormally large parietal lobe
, a portion of the brain critical to spatial skills and mathematical ability, we understand his unfair advantage over the rest of us: he had a bigger better computer back in that part of his brain.
However, increased
brain volume does not necessarily mean that a brain region is performing better at what it usually does.
But for autistic individuals, the enlarged amygdala does actually parallel Einstein’s enlarged parietal lobe—more means more.

To the extent that an autistic child has a larger amygdala, that child will also tend to be more anxious—
a sign that they may be overwhelmed by the environment
.
Autistic children also show enhanced threat detection
, and their amygdalae do not habituate to faces (that is, calm down with repeated exposures) like the amygdalae of nonautistic children.
Critically,
increased amygdala volume at age three
is predictive of poorer social adjustment later at age six.
On top of all of this,
the visual pathways that feed potential threat information to the amygdala
also show evidence of hyperactivity in autistic individuals.
This unusual visual processing in autism may be an advantage when someone is performing perceptual tasks like the embedded-figures task shown in
Figure 7.2
, but it may also contribute to an overintensity of the inputs reaching the amygdala.
Some evidence also suggests that autistic individuals
are hypersensitive to sound and touch, in addition to visual inputs.

These results all paint a picture consistent with the intense world hypothesis.
This still leaves us scratching our heads about why autistic adults show less amygdala activity in response to seeing emotional faces.
Tracking the eye movements of autistic individuals when they are shown pictures of faces gives us a major clue.
When you or I see a face
, we spend most of our time looking two places—the eyes and the mouth, with our time disproportionately spent on the former.
These two spots are especially expressive and convey mountains of information about the emotional state of the other person.
When autistics look at a face, their eye movements suggest that they are looking at it very differently.
Autistics look almost randomly around the face, often looking at the least informative parts of the face.
Nonautistics spend nearly twice as much time looking at the eyes
of the target as individuals with autism do.

These differences in social gazing (that is, how we look at faces)
suggest that people with autism might show less amygdala activity when looking at faces because they don’t look at the emotional parts that typically activate the amygdala.
Richie Davidson’s research group at the University of Wisconsin tested this idea.
They found that when autistic adults looked at the eyes of an emotional target, they showed
greater
amygdala activity than nonautistic individuals, in contrast to the prior studies that had not controlled for the eye movements of the participants.
During development, autistic individuals may learn not to attend to sources of emotional information because it is distressing, and thus in adulthood are less responsive because they are deploying this coping mechanism.
I don’t mean to suggest this is a conscious choice, but many of us engage in self-protective strategies that we have learned through conditioning and have no idea we are using.

Autism is as complex as any known psychological disorder.
It has a complex etiology, involving multiple potential causes and developmental pathways.
But the intense world hypothesis looks promising.
It is counterintuitive because it suggests that what looks from the outside world like insensitivity to the social world is very different from how the autistic individual experiences the world.
It suggests that the autistic individual’s aversion to the social world is a coping mechanism for dealing with the most intense and unpredictable part of the world (that is, people), which overwhelms them, literally, in each encounter.
By missing out on countless social interactions early on, these children lose the opportunity to strengthen their mentalizing abilities during critical periods of brain development.
Many of the vicarious inputs that mature our social minds are simply never seen or heard by these children.

Social Cognition

In the three chapters in Part Three we have seen how miraculous our social mind can be, in both the heights it can reach and the
alienation it can produce when it does not function in the typical way.
Empathy represents the perfect storm of sympathetic sharing of another’s feelings, understanding what is likely being experienced and what kind of help or comfort is needed, and having the prosocial motivation to act on behalf of others without necessarily weighing the costs and benefits to oneself.
Autism too is a perfect storm, but a tragic one, in which overwhelmed young children may choose to protect their current well-being by forgoing training experiences that develop the mental machinery and facilitate connecting with others more effectively in adulthood.

So far we have seen that social pains and pleasures are real, are present in all mammals, and depend on some of the same neural machinery as physical pains and pleasures.
These produce the motivational urge to stay connected with those who can help us survive childhood and thrive the rest of our days.
We have also seen the social cognitive machinery that allows us to convert our urge for social connection into thoughtful and enduring relationships among friends, loved ones, and coworkers.
Using our mindreading abilities lets us proactively plan for how to get along well with others rather than always being a step behind, reactive and defensive.
Our ability to use the mirror neuron system to understand the psychological acts that others engage in, as well as to imitate how those acts are performed, is shared with at least monkeys and great apes.
In contrast, our most sophisticated capacity for mentalizing logically is partially shared by great apes and partially exclusive to us.

Now we turn to evolution’s third and most surprising bet.
The urge to connect and the ability to understand what others think and feel are critical to building an effective social creature.
The pièce de résistance is evolution’s building us to naturally adapt to the groups we are in and become the kind of people those people want to be around.
Here’s where evolution got sneaky.

Part Four
Harmonizing

CHAPTER 8
Trojan Horse Selves

I
n 1641, René Descartes published
Meditations on First Philosophy
, which presented his theory of
mind-body dualism
, later known simply as
Cartesian dualism.
According to Descartes, minds are animated by an immaterial soul distinct from the realm of the physical and all physical processes.
There is the mental and there is the physical, and never the twain shall meet.
A few decades later, J. J. Becher published
Physica Subterranea
, which similarly focused on an invisible entity.
Becher proposed that all flammable materials are ignitable because they contain
phlogiston
, a hypothetical substance without perceivable qualities such as color, odor, taste, or weight.
Like Descartes’ characterization of minds, fire too is animated by a seemingly immaterial substance in this scheme.
Both of these ideas were widely discussed and believed in their day.

Times have changed, and so have the fortunes of these two theories.
Whereas mind-body dualism has been one of the most entrenched ideas of the last millennium, informing policy discussions regarding the ethics of cloning, abortion, and the use of animals in laboratory tests, phlogiston is only occasionally mentioned in scientific circles and then only derisively as a cautionary tale of unscientific theorizing.
One might naturally assume that the reason Cartesian dualism endures while phlogiston has fallen out of favor is that the former has garnered scientific support while the latter has been refuted by science.
But such an assumption would be wrong.

In scientific circles neither theory is reputable, although scientists (including me) still regularly report their findings in dualistic language, referring to the mind as if it is separate from the body.
One of the fundamental tenets of the modern science of the mind is that the mind is a thoroughly biological and therefore material entity.
Nevertheless, people walk around with an ingrained belief in the simple but implausible form of mind-body dualism that Descartes described.
Consider the following dilemma.
Would you rather keep your body but no longer have a mind?
The body would go on acting just as you do, but the experiencing “you” would be gone.
You would no longer have thoughts, feelings, or memories.
Or would you prefer to keep your mind without having a body?
You would still have experience but no body with which to interact with the world.
Any answer to this question is a tacit endorsement of dualism.
The truth is that it is easier to think of ourselves as having both a mind and a body that are distinct from one another.

Me in the Mirror

Descartes’ belief about our dual nature—mind and body—was a profound error about the way nature works, but it was an accurate assessment of how our brains represent the world.
Hundreds of years before the neural data was discovered, Descartes recognized that there is a deep division in these two components of how we see our
self
, body and mind.
Does this mean we have two selves?
If so, which self do we recognize when we see our reflection?

In 1970, Gordon Gallup made a mirror available
to a group of chimpanzees.
He was interested in whether chimps were self-aware—if they had a self and knew they had a self.
The chimps couldn’t talk about themselves, but Gallup thought the way they responded to their own image in the mirror could reveal if they
had a sense of self.
Chimps are our closest genetic relatives so they are the best candidates to have something resembling our sense of self.

As the chimps spent time with the mirror, they engaged in two kinds of behaviors, suggesting a growing awareness of what the mirror image represented.
At first, the chimps acted toward the image as if it were another chimp, someone new in their presence.
By the third day, this behavior trailed off dramatically and was replaced by behaviors that were self-focused.
For instance, they used the mirror to guide themselves to pick food out of their teeth.
After ten days, the key test was performed.
While the chimps were asleep, Gallup placed an odorless red dye on each of their foreheads.
Later, when the chimps were awake, they were shown the mirror again, and chimps showed clear evidence of self-recognition as they saw the dye in the mirror and touched their own foreheads to investigate.
Paralleling work linking social interaction and self-awareness in humans
, Gallup also found that chimps who had been raised in isolation never showed evidence of mirror self-recognition.

Not without some controversy, results like these
from different species have been used to establish that chimps, dolphins, and elephants are self-aware.
Once fMRI became popular decades later, scientists examined self-recognition in the scanner to determine its neural bases.
Across more than a dozen studies a clear pattern has emerged.
When people see and recognize a picture of themselves, in contrast to pictures of friends, celebrities, or strangers, regions in the right prefrontal and parietal cortex on the lateral surface of the brain are more active (see
Figure 8.1
).
In addition, the parietal region that responds
to seeing one’s own face also responds to keeping track of one’s own body movements.

Figure 8.1 Regions in the Right Hemisphere Associated with Visual Self-Recognition

Neural Dualists

For forty years we have taken mirror self-recognition as a decisive sign of self-awareness in others, but the truth is more complicated.
In Cartesian terms, this test focuses on the recognition of our body as our body.
In Descartes’ meditation, it was the irreducibility of our minds that led to his famous maxim
“cogito ergo sum”
(“I think therefore I am”).
Long before Descartes, the Oracle at Delphi urged all to “know thyself,”
and Socrates exhorted us that “the unexamined life is not worth living.”
Westerners have taken on this call to action with increasing intensity over the past millennium.
When we urge people to know themselves, are we talking about the same kind of knowing that lets us know it’s us in the mirror?
Mirror self-recognition is a kind of self-awareness, but is it really representative of the deep kind of self-knowledge that we seek?