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
not only into the caregiver response, but also when the response fails, such as in
instances 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 Dr. 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, Dr. 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."
About the Eunice Kennedy Shriver National Institute of Child Health and Human
Development (NICHD): The NICHD sponsors research on development, before and after birth;
maternal, child, and family health; reproductive biology and population issues; and
medical rehabilitation. For more information, visit the Institute's website at www.nichd.nih.gov.
About the National Institutes of Health (NIH): NIH, the nation's medical research
agency, includes 27 Institutes and Centers and is a component of the U.S. Department of
Health and Human Services. NIH is the primary federal agency conducting and supporting
basic, clinical, and translational medical research, and is investigating the causes,
treatments, and cures for both common and rare diseases. For more information about NIH
and its programs, visit www.nih.gov.
