A baby's most likely
first words are based upon their visual experience, laying the
foundation for a new theory of infant language learning, observed Indiana University psychologists. The findings also suggest new possibilities for the treatment of children with language deficits and autism.
Drawing on theories of statistical learning, IU researcher Linda
Smith and colleagues found that the number of times an object enters an
infant's field of vision "tips the scales" in favor of associating
certain words with certain objects.
‘Children's first words are predictable based on their visual experience with objects and the prevalence of those objects in their visual world’
The research appears in the journal of the Royal Society Philosophical Transactions B
in a special issue on statistical learning.
"We think that children's first words are predictable based on their
visual experience with objects and the prevalence of those objects in
their visual world," said Smith, a professor in the IU Bloomington
College of Arts and Sciences' Department of Psychological and Brain
Sciences and senior author on the study.
"Visual memory may be the initial key to getting words stuck on
objects - familiar visual objects like table, shirt, bottle or spoon,"
she added. "It's an aggregated experience; those very first words may be
learned - slowly and incrementally - for a few visually pervasive
objects. This may be how infants begin to break into language before
their first birthday."
The study's results could also help inform interventions for children with delayed speech and other language disorders.
"Difficulty learning words could stem from visual processing
problems," Smith added. "Children who are late talkers have slow or
age-delayed visual processing skills for objects, for example. Children
with autism have object-processing problems as well."
Although many researchers have studied infants' first words to
understand learning, Smith said none have approached the question from
the visual side.
"While studying language acquisition from the 'word side' may
benefit those studying later stages of language learning - at the ages
of 18 months to three years - it cannot account for how children break into
language," she said.
Under the new theory, which Smith and colleagues call the
Pervasiveness Hypothesis, a few highly prevalent objects stand out to
infants among the "clutter" of other less frequent objects to become
their first words.
To conduct their study, IU researchers looked at videos that showed
the visual field of eight children - five girls and three boys -
between eight and 10 months old, the period before children engage in verbal
interactions with parents and caregivers.
The videos came from head-mounted cameras worn by the children an
average of 4.4 hours. Caregivers were told the cameras would observe
children's daily activities, not words or objects specifically.
Caregivers could choose when to activate the camera.
For the purpose of the study, researchers observed mealtime scenes,
defined as any eating by anyone at any time or location - in cars, at
playtime or in a high chair, for example. The recordings yielded 917,207
mealtime frames, with one image sampled every five seconds. Five
objects were recorded for each frame: a total of 745 objects.
Using an accepted method to index child vocabulary, the researchers
then divided the named objects into "first nouns," which are acquired by
half of all 16-month-olds; "early nouns," which are known by half of
all 30-month-olds; and "late nouns," which are acquired at later stages
First nouns include words such as table, shirt, chair, bowl, cup, bottle, food, spoon and plate.
The study's results revealed a strong correlation between the most
frequently appearing objects and "first nouns," with the top 15 of these
words appearing in the images collected by the study.
"The comparison of first and early nouns was particularly striking,
since both sets of object names are acquired quite early in childhood
and refer to objects common in households with infants," said Elizabeth
Clerkin, a Ph.D. student in the IU Bloomington Department of
Psychological and Brain Sciences and first author on the study.
"That infants' visual environment during mealtime consistently
involves a very small number of objects - and the names of these
high-frequency objects are among those normally learned first by infants
- suggests visual experience is doing the heavy lifting in very early
word learning," she added.
Whether children who experience speech disorders are not picking up
visual regularities in the environment or simply live in households with
fewer regularities, Smith said it's vital to explore the role of both
words and vision in language learning.
"Taking account of the visual brings a whole new dimension of
word-learning into view," she added. "If all you ever worry about is the
word side of word-learning, you may be missing half the problem: visual
cues that aid language learning."