New Scientist - USA (2022-04-09)

9 April 2022 | New Scientist | 23

Human brain

PEOPLE are better at navigating

environments that are similar

to those in which they grew up.

Hugo Spiers at University College

London and his colleagues have

previously used a mobile video

game called Sea Hero Quest to

work out that those who grew up

outside cities have a better sense

of direction than those who spent

their childhood in these urban areas.

To do this, Spiers’s team tracked

how efficiently players navigated

a virtual world after seeing a map.

Now, the team has analysed data

from nearly 10,000 people aged

19 to 70 who played all 75 levels

of the game, finding that those who

grew up in cities aren’t always

worse at navigation. They come

out on top when finding their way

around grid-like structures that

reflect the layout of many cities.

People who grew up in areas

outside cities are better on more

wiggly routes. Where people lived

when playing the game had no

effect (Nature, doi.org/hn36).

Spiers speculates that where

you grow up may affect the way

neurons called grid cells, part of the

brain’s positioning system, transmit

electrical signals during a critical

stage of development. These cells

and their pattern of activity may

then remain for life. Carissa Wong

Where you grew up affects

where you navigate best

SH

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Fish know how to

add and subtract

The zebra mbuna (pictured)

and ocellate river stingray

can respond to pictures

of colourful shapes in a

way that suggests they

understand addition and

subtraction. The fish

learned to add or subtract

“1” from a small total such

as 3 in order to obtain a

reward (Scientific Reports,

doi.org/hn3p).

Warm autumns are

bad for butterflies

The green-veined white

butterfly forms a pupa – or

chrysalis – in autumn and

enters a dormant state as

the weather turns cold.

Now lab tests show that

if the autumn is too mild,

the pupa remains active

and uses so much energy

that a butterfly is unable

to emerge in spring

(Functional Ecology,

doi.org/hn3q).

Floods after fire to

occur more often

Extreme rainfall events

following wildfires are set

to become more common

in the western US due to

climate change, according

to a model. The rainfall may

lead to floods, because the

vegetation that soaks up

water has been lost during

the fires (Science Advances,

doi.org/hn9r).

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Really brief

Solar system

PLUTO has huge ice volcanoes that

may still be active. An analysis of

data from NASA’s New Horizons

spacecraft has revealed that at

least 180,000 square kilometres of

Pluto’s surface is made of ice that

seeped out from underground via

cryovolcanism relatively recently.

This area, around two

mountains called Wright Mons

and Piccard Mons, is made up

of undulating hummocks of ice.

“There’s not really anything

anywhere else in the solar

system that looks like this,” says

Kelsi Singer at the Southwest

Research Institute in Colorado.

Singer’s team examined images,

data and maps of the area and

found that it was probably created

via effusive cryovolcanism. This is

when liquid or soft ice seeps out

from underground to gradually

create mountains. Wright Mons

and Piccard Mons appear to be

cryovolcanoes as large as the

biggest active volcanoes on

Earth, but there is no evidence

of explosive eruptions (Nature

Communications, doi.org/hn4c).

The lack of impact craters from

asteroids hints that the ice isn’t

that old. “It probably formed

within the last couple hundred

million years, but we’re not sure if

it’s still ongoing,” says Singer. LC

Pluto may have

active ice volcanoes

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Language

WHEN people use gender-neutral

words like “people” and

“humanity”, they tend to be

thinking of men rather than

women, in reflection of sexism

present in many societies,

according to an analysis of billions

of words published online.

The researchers behind the

work warn that this sexist bias

is being passed on to artificial

intelligence models that have

been trained on the same text.

April Bailey at New York

University and her colleagues used

a statistical algorithm to analyse a

set of 630 billion words contained

within 2.96 billion web pages,

gathered in 2017. It includes

informal text from discussion

forums and blogs as well as text

from the media, corporations and

governments, mostly in English.

The researchers used an

approach called word embedding

to derive the intended meaning

of a word from the frequency

it occurs with other words.

Words like “person”, “people”

and “humanity” were used in

contexts that better match the

context of words like “men”, “he”

and “male” than those of words

like “women”, “she” and “her”

(Science Advances, doi.org/hn9q).

The study says that people may

see the gender-inclusive words

as more male in their conceptual

meaning – a reflection of male-

dominated society. This evidence

of sexist bias is unsurprising, says

Bailey, but it should be concerning

because the same texts are used

to train AI tools that will inherit

this bias, including translation

websites and conversation bots.

Matthew Sparkes

‘People’ online

mostly means men