Distinct
patterns of activity—which may indicate a predisposition to care for
infants– appear in the brains of adults who view an image of an infant
face—even when the child is not theirs, according to a study by
researchers at the National Institutes of Health and in Germany, Italy,
and Japan.
Seeing
images of infant faces appeared to activate in the adult’s brains
circuits that reflect preparation for movement and speech as well as
feelings of reward.
The
findings raise the possibility that studying this activity will yield
insights into care giving behavior, but also in cases of child neglect
or abuse.
“These
adults have no children of their own. Yet images of a baby’s face
triggered what we think might be a deeply embedded response to reach out
and care for that child,” said senior author Marc H. Bornstein, Ph.D.,
head of the Child and Family Research Section of the Eunice Kennedy
Shriver National Institute of Child Health and Human Development, the
NIH institute that collaborated on the study.
While
the researchers recorded participants’ brain activity, the participants
did not speak or move. Yet their brain activity was typical of patterns
preceding such actions as picking up or talking to an infant, the
researchers explained. The activity pattern could represent a biological
impulse that governs adults’ interactions with small children.
From
their study results, the researchers concluded that this pattern is
specific to seeing human infants. The pattern did not appear when the
participants looked at photos of adults or of animals—even baby animals.
Along
with Bornstein, the research was carried out by first author Andrea
Caria, Ph.D., of the University of Tuebingen, in Germany; Paola Venuti
of the Department of Cognitive Science of University of Trento in Italy;
Gianluca Esposito of the RIKEN Brain Science Institute in Saitama,
Japan; researchers from the Max Planck Institute for Biological
Cybernetics and Eberhard Karls University, in Tuebingen, Germany.
Their findings appear in the journal NeuroImage.
To
collect the data, the researchers showed seven men and nine women a
series of images while recording their brain activity with a functional
magnetic resonance imaging scanner. In the scanner, participants viewed
images of puppy and kitten faces, full-grown dogs and cats, human
infants and adults.
When
the researchers compared the areas and strength of brain activity in
response to each kind of image, they found that infant images evoked
more activity than any of the other images in brain areas associated
with three main functions:
- Premotor
and preverbal activity: The researchers documented increased activity
in the premotor cortex and the supplemental motor area, which are
regions of the brain directly under the crown of the head. These regions
orchestrate brain impulses preceding speech and movement but before
movement takes place. - Facial
recognition: Activity in the fusiform gyrus—on each side of the brain,
about where the ears are—is associated with processing of information
about faces. Activity the researchers detected in the fusiform gyrus may
indicate heightened attention to the movement and expressions on an
infant’s face, the researchers said. - Emotion
and reward: Activity deep in the brain areas known as the insula and
the cingulate cortex indicated emotional arousal, empathy, attachment
and feelings linked to motivation and reward, the researchers said.
Other studies have documented a similar pattern of activity in the
brains of parents responding to their own infants.
Participants
also rated how they felt when viewing adult and infant faces. They
reported feeling more willing to approach, smile at, and communicate
with an infant than an adult. They also recorded feeling happier when
viewing images of infants.
Taken
together, the researchers contend, the findings suggest a readiness to
interact with infants that previously has been only inferred, and only
from parents. Such brain activity in nonparents could indicate that the
biological makeup of humans includes a mechanism to ensure that infants
survive and receive the care they need to grow and develop.
However,
signs of readiness to care for a child that appear in the brains of
some or even most adults do not necessarily mean the same patterns will
appear in the brains of all adults, Bornstein said. “It’s equally
important to investigate what’s happening in the brains of those who
have neglected or abused children,” he said. “Additional studies could
help us confirm and understand what appears to be a parenting instinct
in adults, both when the instinct functions and when it fails to
function.”
