ADVANCES
18 Scientific American, May 2022Sumiko Scott/Getty ImagesCOGNITIONDon’t Overthink It
Reducing reasoning may help to learn language
Children often learn new languages more easily than adults do,
but it’s unclear why. Some hypothesize that grasping a language
requires absorbing subtle patterns unconsciously and that adults’
superior conscious reasoning interferes. New research suggests
that, indeed, grown-ups might just be too smart for their own good.
For a recent study in the Journal of Experimental Psychology:
General , a group of Belgian adults simultaneously read and heard
strings of four made-up words (such as “kieng nief siet hiem”).
Specific consonants always appeared at the beginning or end of a
word if the word contained a certain vowel. Participants next read
the sequences aloud quickly. Their ability to avoid mistakes doing
so indicated how well they absorbed the consonant-vowel patterns.
But before exposure to the new words, the participants had
carried out a separate test: pressing keys to
react to letters and numbers. Some
got a much faster, more mentally
draining version of this test.
Those who tackled the difficult
version claimed greater cogni-
tive fatigue afterward—but
performed better on the sub-
sequent language task. The
researchers hypothesize that
tired learners used less con-
scious analysis on the word rules:
they were free to learn like a child.
For a related paper, in the Proceed-
ings of the National Academy of Sciences
USA , the team had English-speaking adults listen to streams of syl-
lables secretly clustered into three-syllable “words.” Later, they
played pairs of three-syllable clusters; one word in the pair came
from the stream, and one was a new combination. The participants
guessed which word was familiar, then rated their confidence.
In one participant group, some had first done the original men-
tally draining test. In another, some had received magnetic pulses
to disrupt activity in a brain area that previous research has linked
to executive control. In both groups, these interventions improved
participants’ performance on the syllable task when they were
unsure about their answers, indicating unconscious parsing of
speech. (Confident answers suggested conscious recall instead.)
Georgetown University neuroscientist Michael Ullman, who
was not involved in either paper, likes that the studies taxed cogni-
tive control differently and measured different skills. “That’s really
good in science because you’ve got converging evidence,” he says,
adding that he would like to see higher language skills such as
grammar studied this way.
Ghent University psychologist Eleonore Smalle, who spear-
headed both papers, offers advice based on her team’s findings.
When beginning to learn a language, she says, immerse yourself in
its sounds, even—or especially—while distracted. “Have a good
glass of wine while listening to a podcast in Italian,” she suggests
with a laugh. “Why not? It could help.” — Matthew Hutson
VIROLOGYPollen Passengers
Hundreds of viruses travel through plant pollination
There’s more than just pollen riding on a springtime breeze. Just
as some human viruses spread when humans reproduce, plant vi-
ruses can use pollen to hitch a ride from flower to flower. A study
in Nature Communications shows how plentiful pollen-borne virus-
es are—and suggests that human activity may help them spread.
University of Pittsburgh evolutionary ecologist Tia-Lynn Ash-
man and her colleagues used genetic sequencing to catalog virus-
es on wildflower pollen from four different environments: Califor-
nia grasslands, the California coast, an agricultural area in Pennsyl-
vania and the Appalachian Mountains. The team found 22 known
viruses—some of which have serious effects on crops. They also
found evidence of hundreds of viruses scientists had never seen.
The findings match results across microbiology, says University
of Florida plant virologist Amit Levy, who was not part of the study:
“There’s just way more viruses everywhere than we expected.”
The team also discovered an interesting correlation. Flowers
from the agricultural site carried genome snippets from more than
100 different viruses, whereas flowers from the California grass-
lands (where human activity is lowest among the areas studied)
had only around a dozen. The other sites had intermediate viral di-
versity. The researchers hypothesize that plant homogeneity within
crop fields could encourage more viruses to inhabit these areas—
once a virus evolves to infect a crop, it finds many compatible hosts.
Although this link is preliminary, Levy says it makes sense that
industrial agriculture might breed plant pathogens. With plants
packed together, “there’s no social distancing between the crops.”
Ashman wonders if honeybees, which farmers often breed,
could also exacerbate plant virus spread in agricultural areas. Hon-
eybees are less choosy about which plants to visit than most native
bees, potentially carrying viruses between wildflowers and crops.
Hernan Garcia-Ruiz, a virologist at the University of Nebraska–
Lincoln who was not involved with the new study, says it grabbed
his attention because the authors uncovered a plethora of viruses
even in plants that did not appear sick. But such microbes may not
be as benign if transmitted from wild plants to crops. Garcia-Ruiz
cites sugarcane mosaic virus—a serious sugarcane and corn path o-
gen that hides in wild grasses in between crop seasons. “As soon as
the corn is available, insects move the virus back into corn,” he says.
Ashman agrees that it is important to understand viruses’
effects on a variety of plants, especially if humans are encourag-
ing spread from natural habitats to agriculture and back. As a
scientific hypothesis, she finds this prospect “tantalizing”—but
“possibly frightening.” — Saima May SidikHoneybee visits a California golden poppy.