By 9-months infants are sensitive to native-language sound combinations. Our studies show that while younger infants discriminate clusters, they are not sensitive to differences in statistical frequency. Thus, the emergence of phonotactic knowledge is driven by experience with the frequency of occurrence of the sound combinations in one’s language.
Twelve- and 15-month-old infants who received simple verbal cues at encoding and retrieval exhibited superior representational flexibility on an imitation task compared to infants who did not receive those cues. Verbal cues can help early-verbal infants overcome perceptual dissimilarity and express knowledge in novel situations.
During the past ten years, research using Near-infrared Spectroscopy (NIRS) to study the developing brain has provided groundbreaking evidence of brain functions in infants. This paper presents a theoretically-oriented review of this wealth of evidence, summarizing recent NIRS data on language processing, without neglecting other neuroimaging or behavioral studies in infancy and adulthood. We review three competing classes of hypotheses (i.e. signal-driven, domain-driven, and learning biases hypotheses) regarding the causes of hemispheric specialization for speech processing. We assess the fit between each of these hypotheses and neuroimaging evidence in speech perception and show that none of the three hypotheses can account for the entire set of observations on its own. However, we argue that they provide a good fit when combined within a developmental perspective. According to our proposed scenario, lateralization for language emerges out of the interaction between pre-existing left-right biases in generic auditory processing (signal-driven hypothesis), and a left-hemisphere predominance of particular learning mechanisms (learning-biases hypothesis). As a result of this completed developmental process, the native language is represented in the left hemisphere predominantly. The integrated scenario enables to link infant and adult data, and points to many empirical avenues that need to be explored more systematically.
Conclusion: Although our effect sizes were small, breastfeeding for four months or longer was associated with improved developmental outcomes for children aged one to three years after adjustment for multiple confounding factors.
from Acta Paediatrica
Communicative Function Demonstration induces kind-based artifact representation in preverbal infants
Human infants grow up in environments populated by artifacts. In order to acquire knowledge about different kinds of human-made objects, children have to be able to focus on the information that is most relevant for sorting artifacts into categories. Traditional theories emphasize the role of superficial, perceptual features in object categorization. In the case of artifacts, however, it is possible that abstract, non-obvious properties, like functions, may form the basis of artifact kind representations from an early age. Using an object individuation paradigm we addressed the question whether non-verbal communicative demonstration of the functional use of artifacts makes young infants represent such objects in terms of their kinds. When two different functions were sequentially demonstrated on two novel objects as they emerged one-by-one from behind a screen, 10-month-old infants inferred the presence of two objects behind the occluder. We further show that both the presence of communicative signals and causal intervention are necessary for 10-month-olds to generate such a numerical expectation. We also found that communicative demonstration of two different functions of a single artifact generated the illusion of the presence of two objects. This suggests that information on artifact function was used as an indicator of kind membership, and infants expected one specific function to define one specific artifact kind. Thus, contrary to previous accounts, preverbal infants’ specific sensitivity to object function underlies, guides, and supports their learning about artifacts.
An imitation procedure was used to investigate the impact of demonstrator familiarity and language cues on infant learning from television. Eighteen-month-old infants watched two pre-recorded videos showing an adult demonstrating a sequence of actions with two sets of stimuli. Infants’ familiarity with the demonstrator and the language used during the demonstration varied as a function of experimental condition. Immediately after watching each video, infants’ ability to reproduce the target actions was assessed. A highly familiar demonstrator did not enhance infants’ performance. However, the addition of a narrative, developed from mothers’ naturalistic description of the event, facilitated learning from an unfamiliar demonstrator. We propose that the differential effect of demonstrator familiarity and language cues may reflect the infants’ ability to distinguish between important and less important aspects in a learning situation.
CONCLUSION. Television viewing in infancy does not seem to be associated with language or visual motor skills at 3 years of age.