Scientific American Mind

44 Pages·2019·8.923 MB·English

MARCH /APRIL 2019 | SCIENTIFICAMERICAN.COM/MINDMAGAZINE
SPECIAL REPORT
THE NEW
SCIENCE OF
CONSCIOUSNESS
What is it? A stream of
unconscious thought,
synced vibrations or
just an illusion?
PLUS
THE LEGACY OF NAZI PARENTING
THE NEUROSCIENCE OF CREATIVITY
WITH COVERAGE FROM
IS YOUR SMARTPHONE MAKING YOU DUMB?
FROM
THE
EDITOR
Your Opinion Matters!
Help shape the future
of this digital magazine.
Let us know what you
think of the stories within
these pages by emailing us:
S
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M [email protected].
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The Illusion of Mind
It may be one of the greatest scientific mysteries yet to be solved: What is consciousness? It’s an explana-
tory gap that still plagues neuroscientists—that is, what forges the relationship between the brain and the
subjective sensations we call “feelings” or “awareness?” In a special report in this issue, we include several
fresh takes on what gives humans, at the very least, consciousness. In one article, Peter Carruthers sits
down with editor Steve Ayan to explain his hypothesis that consciousness is mostly an illusion (see “There
Is No Such Thing as Conscious Thought”); the thoughts and feelings that arise in your mind are a result of
unconscious mental processes operating behind the scenes. You feel you know your own mind, but it’s
truly operating automatically. Dare I say the mind has a mind of its own?
Ayan further explores this idea in his article “The Brain’s Autopilot Mechanism Steers Consciousness.”
Consciousness is only an impression of immediacy, he writes. We become aware of our consciousness
when the brain’s background activities and predictions conflict with reality. Another fun idea that has come
together in the past decade is that synchronized vibrations among living creatures are at the heart of hu-
man consciousness. Read more in Tam Hunt’s article “The Hippies Were Right! It’s All about Vibrations,
Man!” As always, I hope you enjoy this issue, as much as your conscious mind allows. S
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On the Cover M
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The New Science of Consciousness T
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Andrea Gawrylewski What is it? A stream of G
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Collections Editor unconscious thought, synced D
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[email protected] vibrations or just an illusion? O
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WHAT’S
March/April 201 9
Volume 30• No. 2
INSIDE
NEWS FEATURES OPINION
4. 11. 34.
How Dad’s Stresses There Is No Such Thing as Conscious Thought Don’t Make Me One
Get Passed Along to Philosopher Peter Carruthers insists that con- with Everything
Offspring scious thought, judgment and volition are illu- The mystical doctrine
Mouse studies show sions. They arise from processes of which we of oneness has creepy
tiny intercellular pods are forever unaware implications
15. 36.
convey to sperm a
legacy of a father’s The Brain’s Autopilot Mechanism Can Intelligence Buy
hard knocks in life Steers Consciousness You Happiness?
6. Freud’s notion of a dark, libidinous unconscious New research suggests
Deep-Brain Recordings is obsolete. A new theory holds that the that higher IQ leads to
May Show Where brain produces a continuous stream of greater well-being by
Unhappiness Lives unconscious predictions enabling one to acquire
21.
New recordings of elec- the financial and
trical activity in the brain The Hippies Were Right: It’s All about Vibrations, educational means
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help reveal the underpin- GE Man! necessary to live a
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nings of bad moods Y I A new theory of consciousness better life
8. TT 15 24. 39.
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Bad First Impressions Harsh Nazi Parenting Guidelines May In the Nature-Nurture
Are Not Set in Stone Still Affect German Children of Today War, Nature Wins
People are more willing The Nazi regime urged German mothers to ignore Environmental influences
to change their mind their toddlers’ emotional needs—the better to are important, too, but
about people they raise hardened soldiers and followers. Attachment they are largely
initially deem “nasty” researchers say that the harmful effects of that unsystematic, unstable
versus those they teaching may be affecting later generations and idiosyncratic
29. 41.
deem “nice”
9. The Neuroscience of Creativity: Is Smart Technology
Alzheimer’s Attack Q&A with Anna Abraham Making Us Dumb?
on the Brain May Vary The latest state of the field of the neuroscience Yes and no: there are
with Race of creativity reasonable arguments
A new study finds Afri- on both sides of the
can-Americans with question
dementia have less
buildup of certain toxic S
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proteins in their brains A
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than do whites Y I
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A STRESSED-OUT and traumatized acids, these particles ejected from a gets there,” says Tracy Bale, a
How Dad’s Stresses
father can leave scars in his chil- cell act like a postal system that neurobiologist at the University of
Get Passed Along dren. New research suggests this extends to all parts of the body, Maryland School of Medicine.
to Offspring happens because sperm “learn” releasing little packages known as Preliminary research by Bale and
paternal experiences via a mysteri- extracellular vesicles. Their contents others, announced in November at
Mouse studies show tiny intercellu-
ous mode of intercellular communi- seem carefully chosen. “The cargo the annual meeting of the Society for
lar pods convey to sperm a legacy of
cation in which small blebs break off inside the vesicle determines not just Neuroscience in San Diego, shows S
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a father’s hard knocks in life G
one cell and fuse with another. where it came from but where it’s how extracellular vesicles can MA
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Carrying proteins, lipids and nucleic going and what it’s doing when it regulate brain circuits and help T
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diagnose neurodegenerative diseas- The big question is cell, she reasoned, could then relay whose dads had experienced stress
es—in addition to altering sperm to that information to sperm cells to before mating. That showed extracel-
how information
disrupt the brain health of resulting transmit at fertilization. She focused lular vesicles act as the conduit for
offspring. on a population of cells that interact transmitting paternal stress signals
about the paternal
Striking evidence that harsh with developing sperm by releasing to the offspring, Chan says.
environment reaches
conditions affect a man’s children molecules that help sperm grow and The findings are “novel and of very
came from crop failures and war-rav- mature. They also secrete extracellu- high impact, especially when we
the womb in the
aged Europe more than a century lar vesicles—and Chan showed it is consider the impact of military
ago. In those unplanned human first place. these vesicles whose contents fuse service or other work environments
experiments, prolonged famine with sperm cells, instilling memories that can confer high stress,” says
appeared to set off a host of health of a dad’s prior stress. Robert Rissman, a neuroscientist at
changes in future generations, Morgan, a postdoc in Bale’s lab who In one set of experiments Chan the University of California, San
including higher cholesterol levels helped create the mouse model. stressed a group of male mice, let Diego, who was not involved with the
and increased rates of obesity and The big question is how informa- them mate and looked at stress research. “I think it would be impor-
diabetes. To probe the inheritance of tion about the paternal environment responses in the pups. The clincher tant to better understand the speci-
such changes at the cellular level, reaches the womb in the first place. was a set of in vitro fertilization–like ficity of the effect and how different
Bale and her co-workers performed After all, Morgan says, the “dad is experiments in which she collected types of stressors or strength of
a series of mouse experiments. only in there for one night, perhaps sperm from a male mouse that had stressors can modulate this system.”
It is pretty easy to stress out a just a few hours.” Could his sperm never experienced induced stress. As a first step toward translating
mouse. Stick one into a tube it carry memories of prior trauma? The Half his sperm went into a lab dish the findings to people, Morgan is
cannot wriggle out of, soak its idea seemed reasonable yet contro- with vesicles previously exposed to collaborating with University of Penn-
bedding or blast white noise—and versial. Because DNA is packed so stress hormones. The other half was sylvania psychiatrist Neill Epperson
stress hormone levels shoot up, tightly in the nucleus of a sperm cell, cultured with vesicles that had no to track protein and RNA changes in
much as they do in people worrying “the thought that [the cell] would contact with stress hormones. human sperm samples. At the
about finances or facing incessant respond to anything in the environ- Chan injected sperm cells from neuroscience meeting, Morgan
pressure at work. Remarkably, the ment really boggled people’s minds,” each batch into eggs from a non- presented data from a six-month
way a mouse physiologically re- says Jennifer Chan, a former Ph.D. stressed female, then implanted the study of 20 undergraduate and
sponds to stress looks noticeably student in Bale’s lab who is now a fertilized eggs—zygotes—into the graduate students. Each month the
different if—months before concep- postdoc at Icahn School of Medicine same foster mom. The pups from participants came in and gave a
tion—its father endured a period of at Mount Sinai in New York City. nonstressed zygotes developed sperm donation. They also completed
stress. Somehow “their brain devel- Rather, there must be some other normally. Pups from stress-exposed a same-day survey asking how
ops differently than if their dad hadn’t kind of cell whose DNA does react zygotes, however, showed the same stressed they were feeling. Prelimi-
experienced that stress,” says Chris to environmental changes—and that abnormal stress response as those nary data suggest just several
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months after a student reports
stress, his sperm shows changes in
“small noncoding RNAs”—RNA
molecules that do not get translated
to protein but instead control which
genes get turned on or off.
Analyzing sperm from this group
of healthy young men, the research-
ers plan to build a basic understand-
ing of molecular changes linked with
mild stresses such as taking final
exams. In the future Bale and her
colleagues hope to compare these
baseline fluctuations with changes
induced by more prolonged life
stressors such as post-traumatic
stress disorder or neurological
diseases such as autism and
schizophrenia.
The molecular signatures in
extracellular vesicles may also help
researchers discover new ways to
noninvasively diagnose or predict
adverse health outcomes in off-
spring, says Gerlinde Metz, who NEUROSCIENTISTS ARE coming years ago? Wow, I really am a loser.”
studies transgenerational inheri- Deep-Brain Record- closer to understanding why some The spiral into such a mood may
tance of stress responses at the ings May Show Where bad moods seem to tumble uncon- occur in a brain network that
University of Lethbridge in Alberta trollably through your head like a connects two key regions involved
Unhappiness Lives
and was not involved with the collapsing chain of dominoes. One with memory and negative emotions,
research. If so, the vesicles could New recordings of electrical activity misbegotten thought after another says psychiatrist Vikaas Sohal of the
become the basis for a pioneering in the brain help reveal the under- drives you to imagine frightful things University of California, San Francis- ES
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type of stress test. pinnings of bad moods to come or to relive your shameful co. In a study he co-authored, M
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—Esther Landhuis past: “Remember that one thing five published in November in Cell, Sohal T
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says he was able to tell if someone’s report their moods every few hours, “People have a very Sohal says his team’s findings
mood was getting worse just by the researchers hoped they could use spark ideas about how the brain
vague idea of what
looking at whether this network was the electrodes to get a rare window generates negative moods. It is
active or not. into emotion and the deep brain. “We possible, for example, that when
it means to perceive
Psychiatrists have previously used know that mood is somewhere in the these two brain regions work togeth-
or have an emotion
MRI scans to probe the human brain brain,” Sohal says. His goal was “to er they create a vicious cycle that
and the world of emotions within it. see if we can find patterns of activity drags you down a bad road. “It’s easy
in the brain.”
This technology can show how brain that tell us what mood is.” to imagine that you might be feeling
activity changes within a few seconds, Chang implanted electrodes on the —Brendon Watson bad, and then remembering bad
but the brain tends to work a lot surfaces and inside the brains of 21 experiences, and then feeling worse,”
faster than that—neurons can fire patients with epilepsy, recording the Sohal says. “It’s speculative, but that’s
dozens of times a second. MRI organs’ activity continuously for seven regions created synchronized electri- really at the heart of how we think
readings might miss things that to 10 days. Then Sohal scoured the cal pulses that fluctuated between 13 about experiences related to depres-
happen too quickly. Implanted recordings for instances when to 30 times a second, people report- sion and anxiety.”
electrodes, however, can measure electrodes in different parts of a brain ed their moods getting worse. “We If that is right, doctors might figure
changes in brain activity up to 1,000 showed identical measurements of basically found that when there is out how to interrupt that cycle with
times a second. So when U.C.S.F. electrical activity. “Electrical activity of less activity in this network, mood is deep-brain stimulation or electro-
neurosurgeon Edward Chang popped the brain looks like wiggles” from more positive. When there’s a lot of shock therapy for people with major
into Sohal’s office with an idea to use each electrode when displayed on a activity in this network, mood is depressive and anxiety disorders,
internal electrodes to elucidate the graph, Sohal says. “You ask, ‘Okay, do negative,” Sohal says. Watson says. “If this is the part of
neurological underpinnings of mood, the size of those wiggles and the The finding brings scientists closer the brain that makes you feel bad,
Sohal was delighted. locations of the peaks go up together to understanding how the brain maybe you could reverse how that’s
The brain surgery needed to in sync across two electrodes?’” If creates bad moods, says Brendon firing and get yourself to feel better,”
implant electrodes is too risky to they do, it suggests those brain Watson, a psychiatrist and neurosci- he says, adding it will be a long slog
perform on healthy individuals for a regions are communicating. “We call entist at the University of Michigan before this knowledge could be
study like this—but Chang works on that a network,” Sohal says. who was not involved with the study. used in the clinic. “You would need
epilepsy patients who need them One particular network connecting “There’s a major open question in to show that the network correlates
anyway. When other treatments do the hippocampus (an area linked to psychiatry: How do you construct with depression and bipolar epi-
not work, temporarily implanted recollection) and the amygdala (an emotion or mood? People have a very sodes,” he says, “Then study [this
electrodes can show what part of the area linked to negative feelings) vague idea of what it means to therapy] in rats and maybe, if you
brain is causing seizures, allowing began appearing over and over, Sohal perceive or have an emotion in the could convince patients, try studying
Chang to cut that section out during says. “That was our first big ‘Aha!’ brain,” he says, calling the new study it in people.”
surgery. By asking such patients to moment.” Whenever these two brain “a great step for neuroscience.” —Angus Chen
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and their predictions of how many
Bad First Impressions
shocks that person would give
Are Not Set fluctuated more. In other words, their
beliefs about the “bad” subject were
in Stone
more changeable. “A well-designed
People are more willing to brain system would not write some-
change their mind about people one off completely at the first sign of
they initially deem “nasty” versus trouble,” says Molly Crockett, a
those they deem “nice” psychologist at Yale University, who
co-authored a paper about the new
set of studies, published in October
COMMON WISDOM HOLDS that in Nature Human Behaviour. An
negative first impressions are hard open mind helps people forgive and
to shake—and some research backs form bonds, Crockett adds.
this up. But such studies often The test scenarios are a far cry
unfairly compare impressions based from real-world interactions. Still, the
on immoral deeds that are extreme experiment offers “a really elegant
and relatively rare (such as selling paradigm that drills down on a
drugs to kids) with impressions question that’s so central to our
based on kindnesses that are more everyday human life,” says Peter
common (such as sharing an umbrel- Mende-Siedlecki, a psychologist at
la). A new set of studies involving the University of Delaware, who was
precisely balanced behaviors finds not involved in the study. Crockett
that people are more willing to money. One fictional subject re- every three decisions the fictional suspects the findings about social
change their mind about individuals quired more money per shock than subject made, participants rated the impressions reflect a general mental
who initially come off as selfish than the average person did to inflict pain individual on a scale from “nasty” to process of absorbing more informa-
about those they deem selfless. on others. The other’s price-per- “nice,” then specified their confi- tion in threatening situations. She
In three of the experiments, 336 shock threshold was comparably dence in the rating. describes the resultant social
laboratory and online participants lower than the average person’s. As expected, participants rated the tendency as a double-edged sword:
read about two people who each Study participants read about each person who gave shocks for a lower “It’s very good for conflict resolu-
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made a series of 50 decisions subject’s decisions one at a time. price as nastier than the higher-price tion—but at the same time it could H
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regarding how many electric shocks Before seeing each decision, they shocker. But they expressed less trap you in a bad relationship.” S
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to give someone in exchange for predicted what it would be. After confidence in the “nasty” ratings, —Matthew Hutson O
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Alzheimer’s Attack
on the Brain May
Vary with Race
A new study finds African-Ameri-
cans with dementia have less
buildup of certain toxic proteins in
their brains than do whites
RESEARCH ON Alzheimer’s has
mainly focused on Caucasians. New
findings, however, suggest the
disease process that leads to
dementia may differ in Afri-
can-Americans. According to a
study published in January in JAMA
Neurology, the brains of Afri-
can-Americans diagnosed with
Alzheimer’s have less buildup of a
protein called tau—one of the two
hallmark proteins that characterize
the disease.
It is not clear why African-Ameri-
cans would have less tau while still The study also suggests race might in the mid-1980s, has largely been For the moment, the differences
suffering from Alzheimer’s, says affect other aspects of the disease’s of white people,” he notes. “The U.S. detected in the disease’s pathology
neurologist John Morris, who led the pathology, says Morris, who directs in general and the older adult will not change existing treatment
research. But the finding is signifi- the Knight Alzheimer Disease portion of the U.S. population is protocols, which do not yet look at
cant because it means the medical Research Center at Washington increasingly diverse, so we really do certain aberrant proteins to make a
community needs to exercise University in Saint Louis. “The study need to study all populations to try diagnosis. Physicians today diag- ES
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caution when defining Alzheimer’s of Alzheimer’s disease, which really to understand the disease and its nose Alzheimer’s largely based on a M
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by measures of tau buildup alone. began formally in the United States forms.” patient’s neuropsychological charac- T
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teristics. But once researchers have Alzheimer’s occurs more often in African-Americans are known to participants to make the findings
developed a more practical way to black Americans, even if the gene have a different response to inflam- statistically valid. The race a person
measure levels of key proteins itself is more benign. Morris says mation than whites, he says. “There checks off on a form is a crude
involved in the disease, such differ- some blacks may be more likely to may be a different inflammatory biological measure. Eventually, he
ences could be crucial for accurate wait until advanced stages of the response that would lead to a says, this type of study will define
diagnoses, Morris says. Brain scans disease before seeking medical care. different tau-based response.” groups by genetic makeup rather
can detect tau as well as amyloid Other research has suggested In the new research, tau was than self-described race to account
beta—another protein that builds up APOE4 provides some protection measured in cerebrospinal fluid. for the many individuals of mixed
in the brains of Alzheimer’s suffer- against infectious diseases including Patients also underwent PET brain heritage.
ers—but the scans are expensive malaria, and that the gene is more scans to measure amyloid buildup, Morris also urges more investiga-
and not widely available. common in people whose ancestors MRIs to gauge brain volume, genetic tion to understand how Alzheimer’s
The study found no racial differ- came to the U.S. from tropical testing for APOE4 status and other acts in diverse groups of people. “I
ence in amyloid levels. Afri- climates where those diseases are clinical evaluations. “This is a critically hope this publication will stimulate
can-American study participants, more frequent. Among the Saint important study as we move toward the need for our research efforts to
though, had a much lower concen- Louis study participants, African- the goal of individualized medicine,” become more welcoming to people
tration of tangled clumps of the tau Americans were just as likely to Hu says. of color,” he says, “and not settle for
protein, whether or not they had have the APOE4 gene as were If lower levels of the tau protein enrolling individuals who are fairly
dementia. The research looked at Caucasians. But in an earlier study mean a patient has less Alzhei- easy to enroll: upper-class whites.”
1,255 people—some with Alzhei- in Atlanta that also looked at tau mer’s-related damage to the brain, as Keith Fargo, the director of
mer’s, some cognitively normal—in- and APOE4, black Americans with research suggests, African-Ameri- scientific programs and outreach for
cluding 173 African-Americans. dementia were far more likely to cans with these relatively low levels the Alzheimer’s Association, says
The study also found that a variant carry APOE4. African-Americans had might be more responsive to drugs the study is a reminder that measur-
of a gene called APOE4, which lower levels of tau in both studies. that are being developed to attack ing protein levels in the brain and
confers a high risk of Alzheimer’s in Tau may accumulate differently in amyloid, Hu says. Amyloid tends to other advances should not be used
whites, seemed to be less of a peril the brains of African-Americans aggregate before tau in the disease yet in physicians’ offices until they
for African-Americans. The latter because of genetic differences process. are better understood. “It’s a good
tended to have much lower tau levels between the races or because of These regional research efforts, idea to continue to measure these
if they had the APOE4 variant, the chronic stress of racism and oth- Hu says, should spur a nationwide biomarkers in all different kinds of
suggesting they suffered less er factors, notes William Hu, a study that examines how race people—and not get too far ahead of
neurological damage because of the neurologist and researcher at Emory affects various aspects of disease ourselves in terms of clinical prac-
lesser tau exposure. “The mechanism University School of Medicine who progression. Such a study, he adds, tice,” he says.
may be different in AfrIcan-Ameri- led the earlier study. It is unclear should be designed with a propor- —Karen Weintraub
cans than it is in whites,” Morris says. what the mechanism might be, but tionally higher number of black
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