New Scientist - USA (2020-08-22)

22 August 2020 | New Scientist | 15

Ecology Mental health

Michael Le Page Clare Wilson

THE Bornean tufted ground squirrel
became known as the “vampire
squirrel” because of tales of it
slashing the jugular veins of small
deer. But the first study of the
animal’s feeding habits has found
it is a highly specialised seed eater.
Andrew Marshall at the
University of Michigan is part of
a team that has spent decades
studying species in the forests of
Gunung Palung National Park on
the island of Borneo. He and his
colleagues have now put together
all the data on the tufted ground
squirrels (Rheithrosciurus macrotis).
The squirrels have saw-like
incisors, unlike any other mammals,
and the most voluminous tail
relative to body size of any
mammal, making them seem
much larger than they are.
“It’s quite menacing, if a squirrel
can ever be said to be menacing,”
says Marshall.
The squirrels came to the
internet’s attention in 2014, after
a news story called them vampire
squirrels. This moniker was based
on stories told by the local Dayak
people, who say the squirrels jump
on the backs of deer, kill them
by slashing their jugular veins and
then disembowel and eat them.
But Marshall’s team hasn’t
seen this happen. On 60 of the
79 occasions that his team
observed the squirrels feeding,
they were eating the extremely
hard seeds of a big canopy tree
called Canarium decumanum.
On the other 19, they were eating
similar seeds produced by a few
other trees (bioRxiv, doi.org/d6nk).
While he thinks it is unlikely
that the tufted squirrels attack
deer, Marshall isn’t ruling out
the possibility that it happens
occasionally, given that other
Dayak stories have proved true
in the past. “People who spend a
lot of time in the forest see really
unusual things,” he says. ❚

Squirrel said to be

carnivorous actually

eats very hard seeds

MINDFULNESS and other types

of meditation are usually seen

as simple stress-relievers – but

they can sometimes leave

people worse off.

About one in 12 people

who try meditation experience

an unwanted negative effect,

usually a worsening in

depression or anxiety, or even

the onset of these conditions

for the first time, according to

the first systematic review of

the evidence.

“For most people, it works

fine, but it has undoubtedly

been overhyped and it’s not

universally benevolent,” says

Miguel Farias at Coventry

University in the UK, one of the

researchers behind the work.

There are many types of

meditation, but one of the

most popular is mindfulness,

in which people pay attention

to the present moment,

focusing on either their

own thoughts and feelings

or external sensations. It is

recommended by several

National Health Service bodies

in the UK as a way of reducing

depression relapses in people

who have experienced the

condition several times.

Enthusiasm for meditation

may partly stem from a growing

awareness of the side effects of

antidepressant medicines and

the difficulties some people

report in stopping taking them.

There have been some reports

of people experiencing worse

mental health after starting

meditation, but it is unclear

how often this happens.

Farias’s team combed

through medical journals and

found 55 relevant studies. Once

the researchers had excluded

those that had deliberately set

out to find negative effects, they

worked out the prevalence of

people who experienced harms

within each study and then

calculated the average, adjusted

for the study size, a common

method in this kind of analysis.

They found that about

8 per cent of people who try

meditation experience an

unwanted effect. “People have

experienced anything from an

increase in anxiety up to panic

attacks,” says Farias. They also

found instances of psychosis or

thoughts of suicide. The work

will appear in Acta Psychiatrica

Scandinavica.

The figure of 8 per cent

may be an underestimate, as

many studies of meditation

record only serious negative

effects or don’t record them

at all, says Farias.

Katie Sparks, a chartered

psychologist and a member

of the British Psychological

Society, says the figure could

have been pushed up by people

trying out meditation because

of undiagnosed anxiety or

depression. “Meditation has

been found to help people to

relax and refocus and help

them both mentally and

physically,” she says.

But sometimes when people

are trying to still their thoughts,

the mind can “rebel”, she says.

“It’s like a backlash to the

attempt to control the mind,

and this results in an episode of

anxiety or depression,” she says.

This doesn’t mean people

should stop trying meditation,

she says, but instead should

opt for guided sessions, led

by a teacher or an app with a

recorded narration, which she

believes is safer. “The current

study could stop people

participating in something

which can be of benefit in the

right context,” she says. ❚

Need a listening ear? UK

Samaritans: 116123

(samaritans.org). Visit bit.ly/

SuicideHelplines for hotlines

and websites for other countries

The hidden downsides

of mindfulness

MA

RK

O^ G

EB

ER

/GE

TT

Y^ IM

AG

ES

Some people experience

negative effects from

meditation

“ People have experienced

anything from an

increase in anxiety

up to panic attacks”