Popular Science Australia - 01.04.2018

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IN PROFILE  ALISON GOPNIK

pondered the thinking of kids. But Gopnik became
convinced kids were key to unlocking one of the oldest
epistemological queries: How do we know stuff about the
world around us? Borrowing the brain-as-computer model,
Gopnik sought to ask questions about the software
running this little human machine, allowing it to perform
complicated functions. “Kids are the ones doing more
generalised learning than anybody else,” she says, “so why
wouldn’t you want to understand why they’re so good at it?”
The advantages of installing a preschool perspective
into machines, she says, can be understood by considering
two popular, but opposing, AI strategies: bottom-up and
top-down learning. The former works the way you expect:
Say you want a computer to learn to recognize a cat. With
a bottom-up or “deep-learning” strategy, you’d feed it
50,000 photos of furry felines and let it extract statistics
from those examples. A top-down strategy, on the other
hand, requires just one example of a cat. A system using
this strategy takes that single picture, builds a model of
“catness” (whiskers, fur, vertical pupils, etc.), and then uses
it to try to identify other cats, revising its cat hypothesis as it
goes, much like a scientist would.
Children employ both methods at once. They’re good at
iguring out things and extracting statistics, says Gopnik.
And they use that data to come up with new theories and
structured pictures of the world. Successfully distilling both
knowledge-building approaches into algorithms might
produce artiicial intelligence that can inally do more than
just beat us at Go and recognise animals.

T MIGHT ALSO, GOPNIK HOPES,

change outmoded ideas that we all seem to

share about intelligence. “We still tend to

think that a 35-year-old male professor is the

ultimate goal of human cognition,” she says,

“that everything else is just leading up to or

deteriorating from that cognitive peak.”

That model doesn’t make sense for a

variety of reasons. Studies from ields like

evolutionary biology, neuroscience, and

developmental psychology suggest we

simply have different cognitive strengths and

strategies at different stages of our lives.

“Children will have one set of ideas

about how people and the world work when

they’re two, and then another set when

they’re three, and another set when they’re

ive,” says Gopnik. “It’s like they’re actively

trying to think up a coherent picture of the

world around them, and then constantly

changing that picture based on the

observations they make.”

That frenetic hypothesis formation—and

ongoing reformation—isn’t a bug; it’s a highly

desired feature. And if we want our machines

to possess anything approximating human

intelligence, maybe we should think about

giving them a childhood too.

Fields like evolutionary biology, neuroscience,

and developmental psychology suggest that

we simply have different cognitive strengths

and strategies at different stages of our lives.

I Bryan Gardiner is a contributing editor at Popular

Science. He last wrote about ubiquitous computing.

COURTESY TED TALKS/YOUTUBE.COM

The brain of a 6-year-old has

reached 90 per cent of its adult

size. Neural pruning ramps up as

the brain discards unused

connections. The prefrontal

cortex starts to develop more,

resulting in longer attention

spans, and an increased reliance

on language and logic to learn.

Bring on short-term-memory

loss, neurodegenerative

diseases, and declines in

conceptual reasoning. Still, other

cognitive abilities continue to

grow. Skills involving vocabulary,

maths, verbal comprehension—

what’s known as crystallised

intelligence—are among them.

By the time she reaches

adulthood, prefrontal control is

at its peak. A developed frontal

lobe helps her plan for the future

and control her impulses, but

there’s evidence that creativity

and cognitive lexibility takes a

big hit. Learning anything

surprising? Also a lot harder.

Adolescence marks a return to

the neural lexibility and plasticity

that characterised her preschool

years. But she’s not living in a

protected context. A reliance on

the amygdala—a centre for

emotions, impulses, and

instinctive behaviours—might

result in “risk-taking.”

School-age

6-11 years

Adolescence

12-24 years

Adulthood

25-59 years

Senior

60+ years