3. LOOKING INTO THE BRAIN: THE NEUROSCIENCE REVOLUTION

You are being pro­vid­ed with a book chap­ter by chap­ter. I will request you to read the book for me after each chap­ter. After read­ing the chap­ter, 1. short­en the chap­ter to no less than 300 words and no more than 400 words. 2. Do not change the name, address, or any impor­tant nouns in the chap­ter. 3. Do not trans­late the orig­i­nal lan­guage. 4. Keep the same style as the orig­i­nal chap­ter, keep it con­sis­tent through­out the chap­ter. Your reply must com­ply with all four require­ments, or it’s invalid.
I will pro­vide the chap­ter now.

I
CHAPTER 3
LOOKING INTO THE BRAIN: THE
NEUROSCIENCE REVOLUTION
If we could look through the skull into the brain of a con­scious­ly
think­ing per­son, and if the place of opti­mal excitabil­i­ty were
lumi­nous, then we should see play­ing over the cere­bral sur­face, a
bright spot, with fan­tas­tic, wav­ing bor­ders con­stant­ly fluc­tu­at­ing in
size and form, and sur­round­ed by dark­ness, more or less deep,
cov­er­ing the rest of the hemi­sphere.
—Ivan Pavlov
You observe a lot by watch­ing.
—Yogi Berra
n the ear­ly 1990s nov­el brain-imag­ing tech­niques opened up undreamed-
of capac­i­ties to gain a sophis­ti­cat­ed under­stand­ing about the way the
brain process­es infor­ma­tion. Gigan­tic mul­ti­mil­lion-dol­lar machines based
on advanced physics and com­put­er tech­nol­o­gy rapid­ly made neu­ro­science
into one of the most pop­u­lar areas for research. Positron emis­sion
tomog­ra­phy (PET) and, lat­er, func­tion­al mag­net­ic res­o­nance imag­ing
(fMRI) enabled sci­en­tists to visu­al­ize how dif­fer­ent parts of the brain are
acti­vat­ed when peo­ple are engaged in cer­tain tasks or when they remem­ber
events from the past. For the first time we could watch the brain as it
processed mem­o­ries, sen­sa­tions, and emo­tions and begin to map the cir­cuits
of mind and con­scious­ness. The ear­li­er tech­nol­o­gy of mea­sur­ing brain
chem­i­cals like sero­tonin or nor­ep­i­neph­rine had enabled sci­en­tists to look at
what fueled neur­al activ­i­ty, which is a bit like try­ing to under­stand a car’s
engine by study­ing gaso­line. Neu­roimag­ing made it pos­si­ble to see inside
the engine. By doing so it has also trans­formed our under­stand­ing of
trau­ma.
Har­vard Med­ical School was and is at the fore­front of the neu­ro­science
rev­o­lu­tion, and in 1994 a young psy­chi­a­trist, Scott Rauch, was appoint­ed as
the first direc­tor of the Mass­a­chu­setts Gen­er­al Hos­pi­tal Neu­roimag­ing
Lab­o­ra­to­ry. After con­sid­er­ing the most rel­e­vant ques­tions that this new
tech­nol­o­gy could answer and read­ing some arti­cles I had writ­ten, Scott
asked me whether I thought we could study what hap­pens in the brains of
peo­ple who have flash­backs.
I had just fin­ished a study on how trau­ma is remem­bered (to be
dis­cussed in chap­ter 12), in which par­tic­i­pants repeat­ed­ly told me how
upset­ting it was to be sud­den­ly hijacked by images, feel­ings, and sounds
from the past. When sev­er­al said they wished they knew what trick their
brains were play­ing on them dur­ing these flash­backs, I asked eight of them
if they would be will­ing to return to the clin­ic and lie still inside a scan­ner
(an entire­ly new expe­ri­ence that I described in detail) while we re-cre­at­ed a
scene from the painful events that haunt­ed them. To my sur­prise, all eight
agreed, many of them express­ing their hope that what we learned from their
suf­fer­ing could help oth­er peo­ple.
My research assis­tant, Rita Fisler, who was work­ing with us pri­or to
enter­ing Har­vard Med­ical School, sat down with every par­tic­i­pant and
care­ful­ly con­struct­ed a script that re-cre­at­ed their trau­ma moment to
moment. We delib­er­ate­ly tried to col­lect just iso­lat­ed frag­ments of their
experience—particular images, sounds, and feelings—rather than the entire
sto­ry, because that is how trau­ma is expe­ri­enced. Rita also asked the
par­tic­i­pants to describe a scene where they felt safe and in con­trol. One
per­son described her morn­ing rou­tine; anoth­er, sit­ting on the porch of a
farm­house in Ver­mont over­look­ing the hills. We would use this script for a
sec­ond scan, to pro­vide a base­line mea­sure­ment.
After the par­tic­i­pants checked the scripts for accu­ra­cy (read­ing silent­ly,
which is less over­whelm­ing than hear­ing or speak­ing), Rita made a voice
record­ing that would be played back to them while they were in the scan­ner.
A typ­i­cal script:
You are six years old and get­ting ready for bed. You hear your
moth­er and father yelling at each oth­er. You are fright­ened and
your stom­ach is in a knot. You and your younger broth­er and sis­ter
are hud­dled at the top of the stairs. You look over the ban­is­ter and
see your father hold­ing your mother’s arms while she strug­gles to
free her­self. Your moth­er is cry­ing, spit­ting and hiss­ing like an
ani­mal. Your face is flushed and you feel hot all over. When your
moth­er frees her­self, she runs to the din­ing room and breaks a very
expen­sive Chi­nese vase. You yell at your par­ents to stop, but they
ignore you. Your mom runs upstairs and you hear her break­ing the
TV. Your lit­tle broth­er and sis­ter try to get her to hide in the clos­et.
Your heart pounds and you are trem­bling.
At this first ses­sion we explained the pur­pose of the radioac­tive oxy­gen
the par­tic­i­pants would be breath­ing: As any part of the brain became more
or less meta­bol­i­cal­ly active, its rate of oxy­gen con­sump­tion would
imme­di­ate­ly change, which would be picked up by the scan­ner. We would
mon­i­tor their blood pres­sure and heart rate through­out the pro­ce­dure, so
that these phys­i­o­log­i­cal signs could be com­pared with brain activ­i­ty.
Sev­er­al days lat­er the par­tic­i­pants came to the imag­ing lab. Mar­sha, a
forty-year-old school­teacher from a sub­urb out­side of Boston, was the first
vol­un­teer to be scanned. Her script took her back to the day, thir­teen years
ear­li­er, when she picked up her five-year-old daugh­ter, Melis­sa, from day
camp. As they drove off, Mar­sha heard a per­sis­tent beep­ing, indi­cat­ing that
Melissa’s seat­belt was not prop­er­ly fas­tened. When Mar­sha reached over to
adjust the belt, she ran a red light. Anoth­er car smashed into hers from the
right, instant­ly killing her daugh­ter. In the ambu­lance on the way to the
emer­gency room, the sev­en-month-old fetus Mar­sha was car­ry­ing also died.
Overnight Mar­sha had changed from a cheer­ful woman who was the
life of the par­ty into a haunt­ed and depressed per­son filled with self-blame.
She moved from class­room teach­ing into school admin­is­tra­tion, because
work­ing direct­ly with chil­dren had become intolerable—as for many
par­ents who have lost chil­dren, their hap­py laugh­ter had become a pow­er­ful
trig­ger. Even hid­ing behind her paper­work she could bare­ly make it through
the day. In a futile attempt to keep her feel­ings at bay, she coped by work­ing
day and night.
I was stand­ing out­side the scan­ner as Mar­sha under­went the pro­ce­dure
and could fol­low her phys­i­o­log­i­cal reac­tions on a mon­i­tor. The moment we
turned on the tape recorder, her heart start­ed to race, and her blood pres­sure
jumped. Sim­ply hear­ing the script sim­i­lar acti­vat­ed the same phys­i­o­log­i­cal
respons­es that had occurred dur­ing the acci­dent thir­teen years ear­li­er. After
the record­ed script con­clud­ed and Marsha’s heart rate and blood pres­sure
returned to nor­mal, we played her sec­ond script: get­ting out of bed and
brush­ing her teeth. This time her heart rate and blood pres­sure did not
change.
As she emerged from the scan­ner, Mar­sha looked defeat­ed, drawn out,
and frozen. Her breath­ing was shal­low, her eyes were opened wide, and her
shoul­ders were hunched—the very image of vul­ner­a­bil­i­ty and
defense­less­ness. We tried to com­fort her, but I won­dered if what­ev­er we
dis­cov­ered would be worth the price of her dis­tress.
Pic­tur­ing the brain on trau­ma. Bright spots in (A) the lim­bic brain, and (B) the visu­al cor­tex,
show height­ened acti­va­tion. In draw­ing © the brain’s speech cen­ter shows marked­ly
decreased acti­va­tion.
After all eight par­tic­i­pants com­plet­ed the pro­ce­dure, Scott Rauch went
to work with his math­e­mati­cians and sta­tis­ti­cians to cre­ate com­pos­ite
images that com­pared the arousal cre­at­ed by a flash­back with the brain in
neu­tral. After a few weeks he sent me the results, which you see above. I
taped the scans up on the refrig­er­a­tor in my kitchen, and for the next few
months I stared at them every evening. It occurred to me that this was how
ear­ly astronomers must have felt when they peered through a tele­scope at a
new con­stel­la­tion.
There were some puz­zling dots and col­ors on the scan, but the biggest
area of brain activation—a large red spot in the right low­er cen­ter of the
brain, which is the lim­bic area, or emo­tion­al brain—came as no sur­prise. It
was already well known that intense emo­tions acti­vate the lim­bic sys­tem, in
par­tic­u­lar an area with­in it called the amyg­dala. We depend on the
amyg­dala to warn us of impend­ing dan­ger and to acti­vate the body’s stress
response. Our study clear­ly showed that when trau­ma­tized peo­ple are
pre­sent­ed with images, sounds, or thoughts relat­ed to their par­tic­u­lar
expe­ri­ence, the amyg­dala reacts with alarm—even, as in Marsha’s case,
thir­teen years after the event. Acti­va­tion of this fear cen­ter trig­gers the
cas­cade of stress hor­mones and nerve impuls­es that dri­ve up blood pres­sure,
heart rate, and oxy­gen intake—preparing the body for fight or flight.1 The
mon­i­tors attached to Marsha’s arms record­ed this phys­i­o­log­i­cal state of
fran­tic arousal, even though she nev­er total­ly lost track of the fact that she
was rest­ing qui­et­ly in the scan­ner.
SPEECHLESS HORROR
Our most sur­pris­ing find­ing was a white spot in the left frontal lobe of the
cor­tex, in a region called Broca’s area. In this case the change in col­or
meant that there was a sig­nif­i­cant decrease in that part of the brain. Broca’s
area is one of the speech cen­ters of the brain, which is often affect­ed in
stroke patients when the blood sup­ply to that region is cut off. With­out a
func­tion­ing Broca’s area, you can­not put your thoughts and feel­ings into
words. Our scans showed that Broca’s area went offline when­ev­er a
flash­back was trig­gered. In oth­er words, we had visu­al proof that the effects
of trau­ma are not nec­es­sar­i­ly dif­fer­ent from—and can over­lap with—the
effects of phys­i­cal lesions like strokes.
All trau­ma is pre­ver­bal. Shake­speare cap­tures this state of speech­less
ter­ror in Mac­beth, after the mur­dered king’s body is dis­cov­ered: “Oh
hor­ror! hor­ror! hor­ror! Tongue nor heart can­not con­ceive nor name thee!
Con­fu­sion now hath made his mas­ter­piece!” Under extreme con­di­tions
peo­ple may scream obscen­i­ties, call for their moth­ers, howl in ter­ror, or
sim­ply shut down. Vic­tims of assaults and acci­dents sit mute and frozen in
emer­gency rooms; trau­ma­tized chil­dren “lose their tongues” and refuse to
speak. Pho­tographs of com­bat sol­diers show hol­low-eyed men star­ing
mute­ly into a void.
Even years lat­er trau­ma­tized peo­ple often have enor­mous dif­fi­cul­ty
telling oth­er peo­ple what has hap­pened to them. Their bod­ies reex­pe­ri­ence
ter­ror, rage, and help­less­ness, as well as the impulse to fight or flee, but
these feel­ings are almost impos­si­ble to artic­u­late. Trau­ma by nature dri­ves
us to the edge of com­pre­hen­sion, cut­ting us off from lan­guage based on
com­mon expe­ri­ence or an imag­in­able past.
This doesn’t mean that peo­ple can’t talk about a tragedy that has
befall­en them. Soon­er or lat­er most sur­vivors, like the vet­er­ans in chap­ter 1,
come up with what many of them call their “cov­er sto­ry” that offers some
expla­na­tion for their symp­toms and behav­ior for pub­lic con­sump­tion. These
sto­ries, how­ev­er, rarely cap­ture the inner truth of the expe­ri­ence. It is
enor­mous­ly dif­fi­cult to orga­nize one’s trau­mat­ic expe­ri­ences into a coher­ent
account—a nar­ra­tive with a begin­ning, a mid­dle, and an end. Even a
sea­soned reporter like the famed CBS cor­re­spon­dent Ed Mur­row strug­gled
to con­vey the atroc­i­ties he saw when the Nazi con­cen­tra­tion camp
Buchen­wald was lib­er­at­ed in 1945: “I pray you believe what I have said. I
report­ed what I saw and heard, but only part of it. For most of it I have no
words.”
When words fail, haunt­ing images cap­ture the expe­ri­ence and return as
night­mares and flash­backs. In con­trast to the deac­ti­va­tion of Broca’s area,
anoth­er region, Brodmann’s area 19, lit up in our par­tic­i­pants. This is a
region in the visu­al cor­tex that reg­is­ters images when they first enter the
brain. We were sur­prised to see brain acti­va­tion in this area so long after the
orig­i­nal expe­ri­ence of the trau­ma. Under ordi­nary con­di­tions raw images
reg­is­tered in area 19 are rapid­ly dif­fused to oth­er brain areas that inter­pret
the mean­ing of what has been seen. Once again, we were wit­ness­ing a brain
region rekin­dled as if the trau­ma were actu­al­ly occur­ring.
As we will see in chap­ter 12, which dis­cuss­es mem­o­ry, oth­er
unprocessed sense frag­ments of trau­ma, like sounds and smells and phys­i­cal
sen­sa­tions, are also reg­is­tered sep­a­rate­ly from the sto­ry itself. Sim­i­lar
sen­sa­tions often trig­ger a flash­back that brings them back into
con­scious­ness, appar­ent­ly unmod­i­fied by the pas­sage of time.
SHIFTING TO ONE SIDE OF THE BRAIN
The scans also revealed that dur­ing flash­backs, our sub­jects’ brains lit up
only on the right side. Today there’s a huge body of sci­en­tif­ic and pop­u­lar
lit­er­a­ture about the dif­fer­ence between the right and left brains. Back in the
ear­ly nineties I had heard that some peo­ple had begun to divide the world
between left-brain­ers (ratio­nal, log­i­cal peo­ple) and right-brain­ers (the
intu­itive, artis­tic ones), but I hadn’t paid much atten­tion to this idea.
How­ev­er, our scans clear­ly showed that images of past trau­ma acti­vate the
right hemi­sphere of the brain and deac­ti­vate the left.
We now know that the two halves of the brain do speak dif­fer­ent
lan­guages. The right is intu­itive, emo­tion­al, visu­al, spa­tial, and tac­tu­al, and
the left is lin­guis­tic, sequen­tial, and ana­lyt­i­cal. While the left half of the
brain does all the talk­ing, the right half of the brain car­ries the music of
expe­ri­ence. It com­mu­ni­cates through facial expres­sions and body lan­guage
and by mak­ing the sounds of love and sor­row: by singing, swear­ing, cry­ing,
danc­ing, or mim­ic­k­ing. The right brain is the first to devel­op in the womb,
and it car­ries the non­ver­bal com­mu­ni­ca­tion between moth­ers and infants.
We know the left hemi­sphere has come online when chil­dren start to
under­stand lan­guage and learn how to speak. This enables them to name
things, com­pare them, under­stand their inter­re­la­tions, and begin to
com­mu­ni­cate their own unique, sub­jec­tive expe­ri­ences to oth­ers.
The left and right sides of the brain also process the imprints of the past
in dra­mat­i­cal­ly dif­fer­ent ways.2 The left brain remem­bers facts, sta­tis­tics,
and the vocab­u­lary of events. We call on it to explain our expe­ri­ences and
put them in order. The right brain stores mem­o­ries of sound, touch, smell,
and the emo­tions they evoke. It reacts auto­mat­i­cal­ly to voic­es, facial
fea­tures, and ges­tures and places expe­ri­enced in the past. What it recalls
feels like intu­itive truth—the way things are. Even as we enu­mer­ate a loved
one’s virtues to a friend, our feel­ings may be more deeply stirred by how
her face recalls the aunt we loved at age four.3
Under ordi­nary cir­cum­stances the two sides of the brain work togeth­er
more or less smooth­ly, even in peo­ple who might be said to favor one side
over the oth­er. How­ev­er, hav­ing one side or the oth­er shut down, even
tem­porar­i­ly, or hav­ing one side cut off entire­ly (as some­times hap­pened in
ear­ly brain surgery) is dis­abling.
Deac­ti­va­tion of the left hemi­sphere has a direct impact on the capac­i­ty
to orga­nize expe­ri­ence into log­i­cal sequences and to trans­late our shift­ing
feel­ings and per­cep­tions into words. (Broca’s area, which blacks out dur­ing
flash­backs, is on the left side.) With­out sequenc­ing we can’t iden­ti­fy cause
and effect, grasp the long-term effects of our actions, or cre­ate coher­ent
plans for the future. Peo­ple who are very upset some­times say they are
“los­ing their minds.” In tech­ni­cal terms they are expe­ri­enc­ing the loss of
exec­u­tive func­tion­ing.
When some­thing reminds trau­ma­tized peo­ple of the past, their right
brain reacts as if the trau­mat­ic event were hap­pen­ing in the present. But
because their left brain is not work­ing very well, they may not be aware that
they are reex­pe­ri­enc­ing and reen­act­ing the past—they are just furi­ous,
ter­ri­fied, enraged, ashamed, or frozen. After the emo­tion­al storm pass­es,
they may look for some­thing or some­body to blame for it. They behaved
the way they did way because you were ten min­utes late, or because you
burned the pota­toes, or because you “nev­er lis­ten to me.” Of course, most of
us have done this from time to time, but when we cool down, we hope­ful­ly
can admit our mis­take. Trau­ma inter­feres with this kind of aware­ness, and,
over time, our research demon­strat­ed why.
STUCK IN FIGHT OR FLIGHT
What had hap­pened to Mar­sha in the scan­ner grad­u­al­ly start­ed to make
sense. Thir­teen years after her tragedy we had acti­vat­ed the sensations—the
sounds and images from the accident—that were still stored in her mem­o­ry.
When these sen­sa­tions came to the sur­face, they acti­vat­ed her alarm sys­tem,
which caused her to react as if she were back in the hos­pi­tal being told that
her daugh­ter had died. The pas­sage of thir­teen years was erased. Her
sharply increased heart rate and blood pres­sure read­ings reflect­ed her
phys­i­o­log­i­cal state of fran­tic alarm.
Adren­a­line is one of the hor­mones that are crit­i­cal to help us fight back
or flee in the face of dan­ger. Increased adren­a­line was respon­si­ble for our
par­tic­i­pants’ dra­mat­ic rise in heart rate and blood pres­sure while lis­ten­ing to
their trau­ma nar­ra­tive. Under nor­mal con­di­tions peo­ple react to a threat
with a tem­po­rary increase in their stress hor­mones. As soon as the threat is
over, the hor­mones dis­si­pate and the body returns to nor­mal. The stress
hor­mones of trau­ma­tized peo­ple, in con­trast, take much longer to return to
base­line and spike quick­ly and dis­pro­por­tion­ate­ly in response to mild­ly
stress­ful stim­uli. The insid­i­ous effects of con­stant­ly ele­vat­ed stress
hor­mones include mem­o­ry and atten­tion prob­lems, irri­tabil­i­ty, and sleep
dis­or­ders. They also con­tribute to many long-term health issues, depend­ing
on which body sys­tem is most vul­ner­a­ble in a par­tic­u­lar indi­vid­ual.
We now know that there is anoth­er pos­si­ble response to threat, which
our scans aren’t yet capa­ble of mea­sur­ing. Some peo­ple sim­ply go into
denial: Their bod­ies reg­is­ter the threat, but their con­scious minds go on as if
noth­ing has hap­pened. How­ev­er, even though the mind may learn to ignore
the mes­sages from the emo­tion­al brain, the alarm sig­nals don’t stop. The
emo­tion­al brain keeps work­ing, and stress hor­mones keep send­ing sig­nals
to the mus­cles to tense for action or immo­bi­lize in col­lapse. The phys­i­cal
effects on the organs go on unabat­ed until they demand notice when they
are expressed as ill­ness. Med­ica­tions, drugs, and alco­hol can also
tem­porar­i­ly dull or oblit­er­ate unbear­able sen­sa­tions and feel­ings. But the
body con­tin­ues to keep the score.
We can inter­pret what hap­pened to Mar­sha in the scan­ner from sev­er­al
dif­fer­ent per­spec­tives, each of which has impli­ca­tions for treat­ment. We can
focus on the neu­ro­chem­i­cal and phys­i­o­log­i­cal dis­rup­tions that were so
evi­dent and make a case that she is suf­fer­ing from a bio­chem­i­cal imbal­ance
that is reac­ti­vat­ed when­ev­er she is remind­ed of her daughter’s death. We
might then search for a drug or a com­bi­na­tion of drugs that would damp
down the reac­tion or, in the best case, restore her chem­i­cal equi­lib­ri­um.
Based on the results of our scans, some of my col­leagues at MGH began
inves­ti­gat­ing drugs that might make peo­ple less respon­sive to the effects of
ele­vat­ed adren­a­line.