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ลำดับตอนที่ #107 : The man who can´t trust his own brain
A few
months after his brain surgery, Matthew returned to work as a computer
programmer. He knew it was going to be a challenge – he had to explain to his
boss that he was living with a permanent brain injury.
“What
actually happened at the meeting was that the employers said, ‘How can we help
you, how can we make you fit back into work and get back on your feet again?’”
Matthew explains. “That’s what they said. But my recollection the next day was that they were going
to fire me – there was no way they could allow me back into work.”
The
memory was very vivid
– he says – just as believable as anything that had actually happened. Yet it
was completely false. Today, Matthew knows it was one of the first signs that
he was suffering from “confabulation” as a result of his brain injury.
Confabulators don’t mean to lie or mislead, but some fundamental problems with
the way they process memories mean they often struggle to tell fact from a
fiction concocted
by their unconscious mind.
The
discovery was another painful blow to Matthew (whose name has been changed to preserve his privacy). “I
was really scared – I thought I can’t trust what’s actually happened.”
His dilemma, although
extreme, can help us all to understand the frailties of our memories, and the ways our minds
construct their own versions of reality.
Today,
Matthew volunteers at Headway East London, a
charity that supports people with brain injury. I first came across him when he
gave a talk at the Wellcome Collection in London, and keen to know more, I
later interviewed him about his experiences.
He is
quietly spoken and conscientious
as he talks about his past, often turning to confirm details with his colleague
Ben Graham, who he has known for most of the 10 years since his operation. Even
before his injury, Matthew had been very ambitious and driven in the face of
hardship. He was born in Birmingham in the UK, but spent most of his childhood
abroad before moving to live with relatives in London at the age of 17. After
around a month, however, he was kicked out of their home.
He
ended up homeless before living with a Franciscan friar. Going to college in the day and
working evenings and weekends to pay for his keep, he eventually earned a place
at University College London to study mathematics and computer science, and
graduated to find a job as a computer programmer.
It
should have been time for him to reap the rewards of that hard work, but after a few months in
the new job, he started noticing some strange things happening to his body: a
loss of sensation in his fingertips, excruciating headaches and double vision. He often had to work
all day with one eye closed.
A CT
scan revealed that the problem lay at the entrance of one of the brain’s ventricles – the cavities that aid the circulation of cerebrospinal fluid
around our neural
tissue. In Matthew’s brain a little sac of tissue called a “colloid cyst” had grown
to block the entrance of the ventricle, stopping the cerebrospinal fluid from
escaping. “The pressure is building up inside this space in the brain, and the
fluid starts to crush your brain against the side of the skull,” says Vaughan Bell,
a neuroscientist at University College London, who discussed Matthew’s injury
at the Wellcome Collection event. The expanded ventricle was also pressing on
the optic nerve, leading to the double vision.
The
doctors performed emergency surgery, cutting a hole in the skull, around the
hairline, to remove part of the cyst and drain
the excess fluid. Recovering in hospital, he knew that the injury had left him
with serious memory deficits.
He would forget having seen people enter or leaving the room, meaning it seemed
as if they had somehow teleported
in front of him. “I could just remember people appearing in my field of vision and then
disappearing,” he says. Bell says this may have come from damage to the “mammillary bodies” – a
pair of small round nodes
of tissue (hence
the name) that are known to be involved with recollection.
The
mind doesn’t seem to like a blank space, however, and over the course of the
recovery, Matthew’s memory started creatively filling in the gaps left by this amnesia. He once sent an
angry email to the neuropsychiatrist, for instance, asking why he had been
asked to leave rehab. “I can assure you I'm not very well at all, there's
something very wrong with me,” he told them. It was only later that he found
out that he had discharged himself – the decision had been completely his own.
Yet he had a clear memory that the staff had sent him away.
Discovering
this tendency for confabulation was deeply unsettling; it was as if he had discovered his
mind was no longer his own. “Your brain is not just a reality-creating
machine,” Matthew says. “There’s a difference between the things you perceive
and the things the brain creates for you to understand the world you live in.”
Often
the false memories would be built around a preconceptions of the way an event would have
turned out. When he had returned to work, for instance, he had worried that his
bosses would not be sympathetic to his difficulties. “I knew my employers were hardnosed business
people, quite harsh,
very strict with work. So my brain had already put them in a specific box and
expected that they were going to react in a certain way.” Thanks to his
amnesia, he could not remember the details of the meeting – and so his brain
had somehow filled that blank space to match those expectations.
In
some ways, this constructive process could be seen as exaggeration of the ways
we all remember. Whenever we try to recall the past, the brain appears to
reconstruct the event, selecting the details that seem most likely to have
happened. “Behind the scenes the brain is doing a lot of things in selecting
and testing information,” he says. “It’s testing out how strong should those
memories seem and then suppressing
the ones that aren’t relevant.”
None
of us do this with complete accuracy; we can accidentally pull the wrong
information to mind, forming “false memories” in which we remember details that
never happened. Indeed, even for the healthy mind false memories are
surprisingly easy to implant.
In one experiment, psychologists in New Zealand and Canada secretly doctored subjects’ photos
to suggest that they had been on a
hot-air balloon ride. When interviewed about the photo, 50% of
the participants concocted a story about the event, innocently believing that
it had actually occurred.
We are
mostly correct about the important details, however, but thanks to Matthew’s
brain injury, the reality check has gone awry, so a far greater number of memories are
false – though he is by no
means the most extreme case that Bell has come across. “Some people have
memories for things that are impossible – for example, they’ll say, ‘I built a
spaceship and flew around the Moon’.” One visitor to the Headway East London
centre woke up from a coma convinced his girlfriend had been expecting twins.
He clearly remembered seeing the ultrasound scan, and taking photos of the baby
bump – yet she had never been pregnant. “I’d recall those ‘memories’ like I’d
remember something from my childhood: there’s literally no distinction for me,” he
says.
Matthew
now keeps a diary to help him record factual details – where he was, what he
ate, what people said – offering a kind of scaffolding around which he can rebuild a picture
of a day’s events. Even so, he still finds that the false memories can creep
in. “Quite often the confabulation happens when Matthew’s quite anxious and
they take the form of what he’s worried about,” says Ben Graham, Matthew’s
colleague at Headway.
When
they spend time together, Matthew often checks facts with Graham. It’s a delicate task – Graham is
conscious that he may accidentally sow the seeds of a false memory in the way
he phrases something. “You can plant an idea – it’s something I have to be
careful about.”
Despite
these ongoing difficulties, Matthew claims it is not the amnesia and confabulation
that bothers him as much as a constant tiredness that continues to follow the
surgery years down the line. “If the fatigue goes away then I’m happy. Then I can cope
with the memory loss.”
With
his prognosis still uncertain, he’s had to learn to accept the small blessings
in life. When he’s got enough energy, he enjoys getting on his bike and going
for long cycle rides. And although he would like to return to computer
programming full-time, he’s learned not to take the future for granted and to enjoy
the present moment. “Now is good. It’s all you have.”
recollection
(n.)
a memory of
something
the ability to remember things:
vivid (adj.)
Vivid descriptions, memories, etc. produce very clear,
powerful, and detailed images in
the mind:
concocted (v.)
to invent an excuse,
explanation, or story in order to deceive someone:
preserve (v.)
to keep something as it is, especially in order to preventit from decaying or being damaged or destroyed:
dilemma (n.)
a situation in which a difficult choice has to be made between
two different things you could do:
frailties (n.)
weakness and lack of
health or strength:
conscientious
(adj.)
putting a lot of effort into your work:
Franciscan
(n.)
a person belonging to a Christian group originallyestablished by St Francis of
Assisi in 1209
friar. (n,)
a man belonging to one of
several Roman Catholic religiousgroups,
whose members often promise to stay poor
excrucuating = extremely painful
cavities (n,)
a hole, or an empty space between two surfaces:
circulation (n.)
the process in which something such as information, money,
or goods passes from
one person to another:
the number of
people that a newspaper or magazine is regularly sold to
the movement of blood around
the body:
cerebrospinal
(adj.)
relating to both the brain and the spine:
cyst (n.)
a round mass growing just under the skin or deeper in the body, that contains liquid:
drain (v.)
If you drain something, you remove the liquidfrom
it, usually by pouring it away or allowing it to flowaway,
and if something drains, liquid flows away or out of it:
Deficits (n.)
the total amount by which money spent is more than money received:
nodes (n.)
a lump (= raised area) or
swelling on or in a living object:
hence (adv.) therefore
that is the reason or explanation for:
from this time: from now on
amnesia (n.)
a medical condition that makes you unable to rememberthings:
unsettling (Adj.)
preconceptions (n.)
an idea or opinion formed before enough information is available to form it correctly:
hardnosed (adj.)
practical and determined:
harsh (adj.)
unpleasant, unkind, cruel, or more severe than is necessary:
too strong, bright, loud, etc.:
suppress (v,)
to prevent something from being seen or expressed or from operating:
to end something by force:
relevant.(adj)
connected with what is happening or being discussed:
correct or suitable for a particular purpose:
implant (v.)
to put an organ, group of cells, or device into the bodyin a medical operation:
Doctor (v,)
to change a document in order to deceive people:
to secretly put a harmful or poisonous substance into foodor drink:
awry(adj.)
not in the intended way
by no means = certainly not
distinction (n.)
a difference between two similar things:
the quality of being excellent:
the quality of being special or different:
scaffolding (n.)
a structure of metal poles and wooden boards put against a building for workers to stand on when they want to reach the higher parts of the building:
delicate (Adj.)
needing careful treatment, especially because easilydamaged:
needing to
be done carefully:
fatigue (n.)
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