A USER’S GUIDE TO 114 | NewScientist: TheCollection| TheHumanBrain CHAPTER NINE The human mind is the most complex information processing system we know. It has all sorts of useful design features but also many glitches and weaknesses. The problem is, it doesn’t come with a user’s manual. You just have to plug and play. But if anyone knows how to get the best out of our brains, it’s neuroscientists. So we asked some of the best to explain how the human brain performs many of its most useful functions and how to use them to the max. By Caroline Williams 1 on bottom-up distractions by turning off email notifications, putting your phone on silent and so on, Nilli Lavie, a cognitive neuroscientist at University College London, suggests actually giving your brain more to do. Lavie’s work has shown that better control otop-down attention comes not by reducing the number oinputs, but by increasing them. Her load theory says that once the brain reaches its limit osensory processing it can’t ta ke anything else in, including distractions. This seems to work or both distractions and mind wandering, says Lavie. In real lie, she suggests thinking about adding visual aspects to a task that make it more attention-grabbing without making it more difficult – putting a colourul boarder around a blank document and making the bit you are working on purple, perhaps. It works with all the senses, she says, so choosing somewhere with a bit obackground noise might also help. There are also signs that cognitive training might help. Researchers working with people with attention- deficit hyperactivity disorder (ADHD) and brain injuries have ound that cognitive training combined with non- invasive magnetic brain stimulation, can improve ocus on a task t hat needs sustained attention. Wider studies are under way, and initial results seem to suggest that the riht kind obrain training could help more or less anyone. While we wait, the next best option is learning to chill out in exactly the right way. Long-term meditators have been shown to have thicker parts othe brain associated with attention, while other studies have ound that attention test scores improved afer a short course omeditation. So learning to ocus better may be as simple as making time to sit still and ocus on not very much. “Top-downattention is prone to losing focus, or being rudelyinterrupted”Almost every useul eature oyo ur brain begins with attention. Attention determines what you are conscious oat any given moment, and so controlling it is just about the most important thing that the brain can do. To make any sense othe world around us we need to filter out almost everything and ocus solely onwhat is relevant. Not only that, but ocused attention is essential or learning or memorising. So it ollows that iyou can boost your ability to pay attention, you can improve at almost anything. In simple terms, the brain has two attention systems. One, the “bottoms up” system, automatically snaps awareness to potentially important new inormation, such as moving objects, sudden noises or sensations otouch. The system is ast, unconscious and always on (at least when you are awake). The other, the “top down” system, is deliberate, ocused attention, which zooms in on whatever we need to think about, and, hopeully, stays there long enough to get the job done. This is the orm oattention that is useul or doing tasks that require concentration. Unortunately distractibility comes as both a bug and adesign eature. Top- down attention requires effort and so is prone to losing ocus, or being rudely interrupted by the bottom-up system. The good news is that we can tweak our attention settings to stay ocused more easily. As well as cutting down THE MIND MAKE THE MOST OF IT 2 3 4 5 6 7 ATTENTION WORKING MEMORY LOGICAL & RATIONAL THOUGHT LEARNING KNOWLEDGE CREATIVITY INTELLIGENCE 1 ATTENTION TheHumanBrain| NewScientist: TheCollection| 115 N I G E L S U S S M A N
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The human mind is the most complex information processingsystem we know. It has all sorts of useful design features butalso many glitches and weaknesses. The problem is, it doesn’tcome with a user’s manual. You just have to plug and play.
But if anyone knows how to get the best out of our brains, it’sneuroscientists. So we asked some of the best to explain howthe human brain performs many of its most useful functionsand how to use them to the max. By Caroline Williams
1on bottom-up distractions byoff email notifications, puttinphone on silent and so on, Na cognitive neuroscientist at UCollege London, suggests actgiving your brain more to do
Lavie’s work has shown thacontrol o top-down attentionot by reducing the number but by increasing them. Her lsays that once the brain reachlimit o sensory processing it anything else in, including d
This seems to work or botdistractions and mind wandeLavie. In real lie, she suggesabout adding visual aspects tthat make it more attention-g without making it more diffi
putting a colourul boarder ablank document and makingyou are working on purple, pIt works with all the senses, sso choosing somewhere withbackground noise might also
There are also signs that cotraining might help. Research working with people with attdeficit hyperactivity disorderand brain injuries have oundcognitive training combined invasive magnetic brain stimcan improve ocus on a task tsustained attention.
Wider studies are under winitial results seem to suggesriht kind o brain training comore or less anyone.
While we wait, the next be
is learning to chill out in exaright way. Long-term meditabeen shown to have thicker pbrain associated with attentiother studies have ound thatest scores improved afer a scourse o meditation. So learto ocus better may be as simmaking time to sit still and onot very much.
“Top-down attention is proneto losing focus,or being rudely
interrupted”
Almost every useul eature o yourbrain begins with attention. Attentiondetermines what you are consciouso at any given moment, and socontrolling it is just about the mostimportant thing that the brain can do.
To make any sense o the worldaround us we need to filter outalmost everything and ocus solelyonwhat is relevant. Not only that,but ocused attention is essentialor learning or memorising. So itollows that i you can boost yourability to pay attention, you canimprove at almost anything.
In simple terms, the brain has twoattention systems. One, the“bottoms up” system, automaticallysnaps awareness to potentially
important new inormation, suchas moving objects, sudden noisesor sensations o touch. The systemis ast, unconscious and always on(at least when you are awake).
The other, the “top down” system,is deliberate, ocused attention, whichzooms in on whatever we need to thinkabout, and, hopeully, stays there longenough to get the job done. This is theorm o attention that is useul ordoing tasks that require concentration.
Unortunately distractibility comesas both a bug and adesign eature. Top-down attention requires effort and sois prone to losing ocus, or being rudelyinterrupted by the bottom-up system.
The good news is that we can tweakour attention settings to stay ocusedmore easily. As well as cutting down
Learning is what your brain does naturally.In act, it has been doing it every waking
minute since about a month beore you were
born. It is the process by which you acquire
and store useul (and useless) inormation
and skills. Can you make it more efficient?
The answer lies in what happens
physically as we learn. As it processes inormation,
the brain makes and breaks connections, growing
and strengthening the synapses that connect
neurons to their neighbours, or shrinking them
back. When we are actively learning, the making
o new connections outweighs the breaking o old
ones. Studies in rats have shown that this rewiring
pricess can happen very quickly – within hours o
learning a skill such as reaching through a hole to
get a ood reward. And in some parts o the brain,
noteably the hippocampus, the brain grows new
brain cells as it learns.
But once a circuit is in place, it needs to be usedi it is going to stick. This largely comes down to
myelination – the process whereby a circuit that
isstimulated enough times grows a coat o atty
membrane. This membrane increases conduction
speed, making the circuit work more efficiently.
What, then, is the best way to learn things and
retain them? The answer won’t come as a huge
surprise to anyone who has been to school: ocus
attention, engage working memory and then, a bit
later, actively try to recall it.
Alan Baddeley o the University o York, UK, says it is
a good idea to test yoursel in this way as it
causes your brain to strengthen the new connection.
He also suggests consciously trying to link new bits o
inormation to what you already know. That makes
the connection more stable in the brain and lesslikely to waste away through underuse.
The learning process carries on or lie, so why is
it so much harder to learn when we reach adulthood?
The good news is that there seems to be no physiological
reason or the slowdown. Instead, it seems to be a lot to
do with the act that we simply spend less time learning
new stuff, and when
we do, we don’t do it with the same potent mix
o enthusiasm and attention as the average child.
Part o the problem seems to be that adults
know too much. Research by Gabriele Wul at the
university o Nevada, Las Vegas, has shown that
adults tend to learn a physical skill, like hitting a
gol ball, by ocusing on the details o the movement.
Children, however, don’t sweat the details, but
experiment in getting the ball to go where they
want. When Wul taught adults to learn more like
kids, they picked up skills much aster.
This also seems to be true or learning inormation. As adults we have a vast store o mental shortcuts
that allow us to skip over details. But we still have the
capacity to learn new things in the same way as
children, which suggests that i we could resist the
temptation to cut corners, we would probably learn a
lot more.
A more tried-and-tested method is to keep active.
Ageing leads to the loss o brain tissue, but this
may have a lot to do with how little we hare about
compared with youngsters. With a little exercise, the
brain can spring back to lie. In one study, 40 minutes
o exercise three times a week or a year increased the
size o the hippocampus – which is crucial or learning
and memory. It also improved connectivity across the
brain, making it easier or new things to stick.
One o the brain’s most useuleatures is the ability to absorbpieces o inormation and makeconnections between them.Knowledge really is power: a littlecan be a dangerous thing andthe more you know the betterequipped you are to deal with lie.
But what exactly is knowledge?How are acts stored, organisedand recalled when needed?
Knowledge obviously relies
on memory – in particular thetype o memory that storesgeneral inormation aboutobjects, places, acts and people,known as semantic memory.This is the part o memory whichknows that Paris is the capital oFrance, a constitutional republicin western Europe – but not thepart which stores memories o a weekend break there.
Knowledge isn’t so much about what inormation you store ashow you organise it to create arich and detailed understandingo the world that connectseverything you know.
The sight o a dog, or example,automatically activates otherbits o inormation about dogs:how they look, smell, soundand move, the act that they aredomesticated wolves, the nameso similar dogs you know, andyour eelings about dogs.
How the brain achieves thisgargantuan eat is ar rom clear. A recent proposal is that it hasa “hub” that tags categoriesto everything we know and
encounter, allowing us to connectrelated things.
In 2003, Tim Rogers, acognitive psychologist now atthe University o Wisconsin-Madison, proposed the anteriortemporal lobe (ATL) as the hub.The ATL is badly affected inpeople with semantic dementia, who progressively lose theirknowledge o the meanings o words and objects but retaintheir skills and autobiographicalmemories. Experiments sincethen have backed this up – whenthe ATL is temporarily knocked
out by a small electromagneticpulse, people lose the ability toname objects and understand themeanings o words.
Rogers says that withoutthis system we would spend alot o time being conused abouthow things fit together. “How would you iner, or instance,that when making a collage withyour kids, i you run out o stickytape you can use the glue stickinstead?” he says. “The tape isnot similar to the glue stick inits shape, colour or how you useit. You need a representationthat specifies similarity o kind.”
The good news is that thereseems to be no limit to the
knowledge hat can fit into abrain. As ar as we know no onehas ever run out o storage space.
But it seems you can knowtoo much. Michael Ramscarat Tubingen University inGermany reckons that anyone who lives long enough eventuallyhits that point just by virtue oa lietime’s knowledge. Hesuggests that cognitive skillsslow down with age not becausethe brain withers but becauseit is so ull. And that – like anoverused hard drive – takeslonger to sif through.
J.K. Rowling has said that theidea or Harry Potter popped
into her head while she was
stuck on a very delayed train.
We have all had similar –
although probably less
lucrative – “aha” moments,
where a lash o inspiration
comes along out o the blue.
Where do they come rom?
And is there any way to order
them on demand?
Experiments led by John
Kuonios, a neuroscientist
at Drexel University in
Philadelphia, suggests that
the reason we aren’t all
millionaire authors is that
some brains come better set
up or creativity than others.EGG measurements taken
Intelligence hasalways been tricky toquantiy, not leastbecause it seems toinvolve most o thebrain and so isalmost certainly not
one “thing”. Even so, scoresacross different kinds o IQtests have long shown thatpeople who do particularly well – or badly – on oneseem to do similarly on all.This can be crunched intoa single general intelligenceactor, or “g”, whichcorrelates pretty well withacademic success, income,health and liespan.
So more intelligence isclearly a good thing, but where does it come rom? A large part o the answerseems to be genetics. In1990, the firs twin studiesshowed that the IQ scoreso identical twins raisedapart are more similar toeach other those o non-identical twins raisedtogether. Since then, a ewgenes have been linked toIQ, but all o them seem tohave a tiny effect and thereare probably thousandsinvolved (or more on this,see Chapter 3, page 42).
That doesn’t mean theenvironment plays nopart, at least in childhood.While the brain isdeveloping, everythingrom diet to education andstimulation plays a hugepart in developing thebrain structures neededor intelligent thought.Children with a bad dietand poor education may
never ulfil their geneticpotential.
But even or educatedand well-ed children, theeffects o environment wear off over time. Byadulthood, genes accountor 60 to 80 per cent o thevariance in intelligencescores, compared with lessthan 30 per cent in youngchildren. Like it or not, we
get more like our closeamily members the older we get.
So i genes play such abig part, is there anythingadults can do to improveIQ? The good news is thatone type o intelligencekeeps on improvingthroughout lie. Mostresearchers distinguishbetween fluid intelligence, which measures the abilityto reason, learn and spot
patterns, and crystallisedintelligence, the sum o allour knowledge so ar. Fluidintelligence slows down with age, but crystallisedintelligence doesn’t. So while we all get a littleslower to the party as we get older, we can restassured that we are stillgetting cleverer.
The brain is a ickle least – at some times
as sharp as a tack, at others like a uzzy ball
o wool. At least some o that variation can
be explained by luctuations in circadian
rhythms, which means that, in theory, i you
do the right kind o task at the right time o day,
lie should run a little more smoothly.
The exact timing o these luctuations
varies by about 2 hours between morning
and evening types, so it is difficult to give any
one-size-its-all advice. Nevertheless there area ew rules that it’s worth bearing in mind
whatever your natural waking time.
It’s an idea not to do too much that
involves razor-sharp ocus in the irst couple
o hours afer waking up. Depending on how
much sleep you have had it can take anything
rom 30 minutes to 4 hours to shake off
sleep inertia – also known as morning
grogginess. I you want to think creatively,
though, groggy can be good (see “Creativity”,
page 119).
I hard work can’t wait, though, the good
news is that researchers have backed up
what most o us already know – a dose o
caffeine helps you shake off sleep inertia and
get on with some work.
Another tip is to time your mental
gymnastics to coincide with luctuations in
body temperature. Studies measuring variationin everything rom attention and verbal
reasoning to reaction times have shown that
when our core temperature dips below 37°C
the brain isn’t at its best.
By this measure, the worst time to do
anything involving thinking is, unsurprisingly,
between midnight and 6am. It is almost as bad
in the afernoon slump between 2pm and 4pm,
which has more to do with body temperature
than lunch – studies o people who have no
lunch or just a small one have the same
problem. All in all, the best time to get stuck in
is between mid-morning and noon and then again
between 4pm and 10pm.
There may be a way to hack the system,
though. Studies have shown that body
temperature changes and alertness also
work independently o the internal clock, so
a well-timed bit o exercise or hot shower canwork wonders.