Read Welcome to Your Brain Online
Authors: Sam Wang,Sandra Aamodt
Tags: #Neurophysiology-Popular works., #Brain-Popular works
folklore does not have any experimental proof, but is likely to have its roots in the observation that
dreams often incorporate the daily concerns of the dreamer, combined with seemingly random or
senseless events. The existence of trains of thought in dreams and a degree of plot suggests that your
cortex has some ability to construct a coherent story from what it is given—though this may simply
reflect the action of the “interpreter” discussed in
Chapter 1
. In that respect, dreams may constitute a
means of sampling what’s lying around in your head. When we talk about our dreams, we focus on the
extent to which our dreams can be made coherent: waking up in class naked, sailing a ship, rolling a
big rock. But what if the random aspects of dreaming are an essential feature? What if randomly
sampling the brain’s contents as we sleep is a means for transferring our memories to a more
permanent place? Resampling could even be used to correct wrong memories that need to be erased.
Weird dreams may be the price, or perhaps an unintended benefit, of the mechanisms that our brains
use to remember the events of our lives.
A Pilgrimage: Spirituality
How religion is rooted in our biology has been a popular topic for recent books, especially among
atheists who are convinced that religious beliefs are irrational. Prime examples are
The God
Delusion
by biologist and bomb thrower Richard Dawkins and
Breaking the Spell: Religion as a
Natural Phenomenon
by philosopher Daniel Dennett. Considering how little is known about the
neuroscience of religion, it seems premature to claim that biologists have the issue all worked out.
Anthropologists have expressed a more positive view of religion: that it was a powerful early
instrument of group social bonding, which may have provided a survival advantage for religion itself
and for humans who shared the beliefs. Let’s start by reminding ourselves that organized religion is a
remarkable achievement, one of the most sophisticated cultural phenomena in existence. Consider the
basic elements of most religions: believers have elaborate cognitive representations of a supernatural
force that cannot be seen. We plead with the force to reduce harm, bring about justice, or provide
moral structure. We furthermore create an understanding with our fellow humans that this force sets
the same standards of morals, social norms, and religious rituals for all of us. It’s a complicated
business, unique to us among all living beings.
What can neuroscience contribute to our understanding of religion? In one sense, nothing: the
satisfaction derived from religion is unlikely to be changed much by knowing how the brain gives rise
to beliefs. Just as you can use words profitably for a lifetime without understanding formal grammar,
people can benefit from religious belief—and for that matter, many other systems analyzed in this
book—without understanding its basis in the brain. Still, if you’ve come this far, you might be
curious.
Two brain capabilities are particularly important in the formation and transmission of religious
belief. Many animals probably have some form of the first trait: the search for causes and effects. The
second trait, social reasoning, is unusually highly developed in humans. One of the core skills of the
human brain is the ability to reason about people and motives—what scientists call a theory of mind.
The combination of these abilities has generated key features of mental function that are part of
religious belief: our ability to make causal inferences and abstractions, and to infer unseen intentions,
whether they’re the intentions of a deity or some other entity. Neural mechanisms that favor the
formation of religious beliefs are also likely to favor the formation of organized belief movements of
other kinds, including political parties, Harry Potter fan clubs—and militant atheism.
What kind of god would it be who only pushed the world from the outside?
—Johann Wolfgang von Goethe
Most religions seek causes for events in the world. These explanations often take the form of
actions performed by a thinking entity. For example, small children either explicitly or implicitly
assign motives to inanimate objects. Developmental psychologists find that small children think a ball
rolls because it wants to. This way of thinking is so natural to us that we do not hesitate to think of
everyday objects as having personalities. We often assign cars or other machines personalities and
even names. Teakettles whistle cheerily, and storms rage. It seems natural, then, that early humans
might have applied such reasoning to the events of the natural world. This kind of reasoning is seen in
animist religions, which attribute a spirit to living and nonliving objects.
Applying the metaphor of conscious agency to natural events becomes something new when
combined with our intensely social nature. We dedicate considerable mental resources to
understanding others’ motivations and points of view. The growing complexity of a child’s view of
motivation can be seen in play, which starts with simple sensory activation but quickly blossoms into
first-order pretense (“I’m a wagon!”) to baroque role-playing (“Okay, now you pretend to be the
child, and I will pretend that I’m the teacher and the class is making too much noise”).
The attribution of imaginary motives to oneself and to others requires a theory of mind. This
ability allows children to engage in fictional play, like pretending that a toy soldier can fight. As they
acquire a theory of mind, children realize that others have motivations, which they can use in innocent
ways, such as games of hide-and-seek, but also to more nefarious ends, like misleading another
person. At later stages, the sophistication of pretense becomes even more complex; children develop
the ability to understand a staged drama. In
Chapter 24,
we explained that people with autism have
difficulty in understanding that others have motivations and desires, which has profound and
sometimes disastrous effects on their dealings with the world. So the theory of mind is central to our
sense of ourselves and of others.
Assessment of social scenarios requires activity in many cortical areas. One example is mirror
neurons, which fire both when a monkey performs a task and when he sees another monkey do the
same task (see
Chapter 24)
, suggesting that the monkey’s brain understands that the two actions share
something in common. In addition, social communication is impaired in monkeys with damage to the
amygdala (see
Chapter 16)
, a brain structure intimately involved in deriving the emotional
significance of objects and faces, and therefore critical in giving the brain access to knowledge of the
mental states of others. All this brain machinery is likely to be involved in our attempts to explain
things like natural events and complex relationships among nonhuman or inanimate objects.
Religious belief is made possible when the drive for causal explanations is combined with our
brains’ ability—and propensity—to provide advanced levels of social cognition. Together, these two
abilities allow us to generate complex cultural ideas ranging from jaywalking to justice, redemption
to the Resurrection. As we noted in
Chapter 3,
complex social reasoning is related to cortical size.
This strong relationship implies that social cognition requires some serious information-processing
horsepower. The brain arms race that rewarded our ability to cooperate with and outsmart our fellow
beings has also set the stage for religious mental constructs. As a consequence, we can imagine a
God, Yahweh, or Allah that is the cause of everything and judges us, yet who cannot be seen.
Did you know? Meditation and the brain
The Dalai Lama says that when scientific discoveries come into conflict with Buddhist
doctrine, the doctrine must give way. He also has a strong interest in exploring the neural
mechanisms underlying meditation. Like many practitioners, he divides meditation into two
categories: one focused on stilling the mind (stabilizing meditation) and the other on active
cognitive processes of understanding (discursive meditation). Neuroscience’s first pass at
studying meditation focused on the first category. Brain activity in highly skilled
practitioners of stabilizing Buddhist meditation was evaluated by a group of scientists,
including one with a Ph.D. in molecular biology who has since joined the Shechen
Monastery in Nepal as a disciple.
The group was able to draw eight long-term practitioners of Tibetan Buddhist
meditation away from their normal practice (which is spending all day in meditative
retreats). In the laboratory, the monks had electrodes placed on their heads to measure
patterns of electrical activity. At first, the patterns were no different than those of
volunteers meditating for the first time. The difference came when the monks were asked to
generate a feeling of compassion not directed at any particular being, a state that is known
as objectless meditation. Under this condition, the activity began varying in a coherent,
rhythmic manner, suggesting that many neural structures were firing in synchrony with one
another. The increase in the synchronized signal was largely at rates of twenty-five to forty
times per second, a rhythm known as gamma-band oscillation. In some cases, the gamma
rhythms in the monks’ brain signals were the largest ever seen in people (except in
pathological states like seizures). In contrast, naïve meditators couldn’t generate much
additional gamma rhythm at all.
How brains generate synchronization is not well understood, but gamma rhythms are
greater during certain mental activities, such as attending closely to a sensory stimulus or
during maintenance of working memory. This increased gamma-band rhythm may be a key
component of the heightened awareness reported by monks. Are monks born with a natural
ability to generate a lot of brain synchrony? Several types of rhythm seem to get stronger
with experience in novices who learn meditation, suggesting that the capacity is at least
partly trainable.
Brain scanning also identified regions that are active during discursive meditation
(focused attention on a visualized image). Anterior cingulate and prefrontal areas of the
cortex were very active, as they are when Carmelite nuns recall the feeling of mystical
union with God. This work fits with the involvement of these regions in attention. It
probably would also have been of interest to Pope John Paul II, who, in reference to
science and Catholic doctrine, said that they were both true and compatible with one
another because “truth cannot contradict truth.”
If theory of mind is a critical factor in the formation of religion, then animals that display some
kind of theory of mind might be capable of religious belief. Can animals form a mental model of what
others are thinking? In some species, the answer might be yes. For example, consider our friend
Chris’s dog Osa. Because of an injury, Osa was temporarily unable to climb stairs by herself, and
Chris had to carry her up and down. This persisted for months, with her waiting at the top or bottom
of the stairs to be carried. One day Chris came home at midday and was quietly puttering around in
the kitchen. Osa came down the stairs, walking. Halfway down, she saw Chris and froze with a look
that seemed to say, “I am so busted,” which, of course, she was. Osa appeared to be acting on the
assumption that if Chris knew she could walk down stairs, he would stop carrying her. This suggested
to Chris that she could visualize what made Chris tick, at least when it came to schlepping pets up and
down the stairs.
It’s a gigantic leap to assign a theory of mind based on a single look from a dog. One could just as
well say that the story demonstrates Chris’s own theory of mind. However, in more systematic
studies, dogs do appear to take into account other dogs’ attentional states when trying to persuade
them to participate in play, adjusting the signals they send according to what the other dog is doing.
Ethologists and anthropologists study the degree of sophistication of theory of mind by counting
how many levels of intention can be imagined. Osa’s desire to deceive sits at a relatively simple