2 April 2022 | New Scientist | 9AN ARTIFICIAL intelligence
that mimics the operation of
a standard computer within its
neural network could speed up
certain calculations. Researchers
have used it to put an AI inside
an AI and play Pong.
If you want a computer to do
something, you have to write code
that manipulates bits of data. But
if you code an AI-driven neural
network, you have to train it with
feedback before it can do anything.
For instance, a neural network
can distinguish between photos
of cats and dogs after being
shown thousands of examples
and told if its guesses are correct.
Now Jason Kim and Dani Bassett
at the University of Pennsylvania
have a new approach, in which
a neural network runs a code,
just like an ordinary computer.
A neural network is a series
of nodes, or artificial neurons,
that takes an input and returns
a changed output. The pair
calculated what effect individual
artificial neurons had, and used
this to piece together a very simple
neural network that could carry
out basic tasks, such as addition.
Kim and Bassett then linked
several networks together in
chains so they could do more
complex operations, replicating
the behaviour of the logic gates
found in computer chips. These
chains were combined to make
a network that could do things a
classical computer can, including
running a virtual neural network
and a playable version of the game
Pong (arxiv.org/abs/2203.05032).The virtual neural network can
also drastically simplify splitting
up huge computational tasks.
These are often spread over many
processors to gain speed, but take
more power to be split into chunks
that can be run independently by
separate chips, then recombined.
An emerging breed of machine
called a neuromorphic computer,
designed to efficiently run AI
software, may also be able to
help these virtual networks work
faster. While a computer uses its
CPU to carry out tasks, and stores
data in memory, a neuromorphiccomputer uses artificial neurons to
both store and compute, lowering
the number of operations it
must carry out. Neuromorphic
computers may also make it easier
for software to accurately work
with continuous variables, such
as those in physics simulations.
Francesco Martinuzzi at Leipzig
University in Germany says neural
networks running code could
squeeze better performance out of
neuromorphic chips. “There will
definitely be specific applications
where these computers are going
to be outperforming standard
computers. And by far, I believe.”
Abdelrahman Zayed at Montreal
Polytechnic in Canada says this
could be exciting, so long as the
chains can avoid long calculations
failing if an algorithm forgets the
beginning as it is learning the end.
These neural networks would
also need to be scaled up.
“Computers don’t just have one
or two logic gates – a CPU will have
billions of transistors,” says Zayed.
“Just because it worked for two
or three gates, that doesn’t
necessarily mean that it will
scale up to billions.” ❚Technology
Matthew Sparkes
GIROSCIENCE/ALA
MYVirtual computer contained within an
AI could help crunch numbers faster
An abstract illustration
of a neuromorphic
computer chipGenetics
THE two genes for the protein that
is mainly responsible for allergic
reactions to cats have been deleted
from cat cells using CRISPR gene
editing. It is a first step towards
creating hypoallergenic cats, says
US-based company InBio.
“The estimated timeline for
this is several years,” says Nicole
Brackett, who leads the CRISPR
cat team at InBio.
About 15 per cent of people have
allergic reactions to cats. The main
cause of this is a small protein called
Fel d 1 that is secreted by salivary
and skin glands. It is spread over
cats’ fur when felines clean
themselves and can become
airborne as the fur dries.
Fel d 1 consists of two different
subunits, and there are two genes,
called CH1 and CH2, encoding
each subunit. When Brackett and
her colleagues compared the
sequences of the CH1 and CH
genes in domestic cats with those
in other cat species, such as lions,
tigers, cougars and fishing cats,
they found many changes.Because the sequences of genes
with key functions tend to change
little if at all, this suggests that
Fel d 1 isn’t essential. The only way
to find out for sure, however, will
be to see what happens to cats
that cannot produce any Fel d 1.
The team has now deleted either
the CH1 or the CH2 gene from cat
cells growing in culture using the
CRISPR genome editing technique
(The CRISPR Journal, doi.org/hnh8).The next step will be to delete
all copies of the two genes at once,
and to confirm that this prevents
cells making the Fel d 1 protein.
Only then will the team try to
create cats that lack the genes.
“[We have] no particular cat
breeds in mind at the moment,”
says Brackett.
In the 2000s, at least two other
companies announced plans to
modify moggies to eliminate Fel d 1,
but neither managed it. However,
achieving this is now more feasible
thanks to the development
of CRISPR in 2012. ❚Plans to use CRISPR
gene editing to make
hypoallergenic cats
“ Plans to modify moggies
to reduce allergic reactions
to cats are more feasible
thanks to CRISPR” Michael Le Page