Developmental psychology focuses on how psychological constructs change with age. In cognitive development research, however, the specifics of this emergence is often underspecified. Researchers often provisionally assume linear growth by including chronological age as a predictor in regression models. In this work, we aim to evaluate this…

Language is the basis of human communication and is the most important key to complete mental development and thinking. Therefore, children must learn to communicate using appropriate language. For this to happen, the development of language in the child must be understood as a biological process, complete with internal laws and with marked stages…

By 12 months of age, infants exhibit behavioral sensitivity to sound symbolism (e.g. sound-shape correspondences) when they hear universally sound symbolic pseudowords (e.g. "bouba," "kiki"). Here, we investigated whether infant's sensitivity to sound-shape correspondences is affected when they hear language-specific sound…

Infancy is a period of significant change for both the brain and behavior. During the first two years of life, the brain experiences an explosion of synaptic connections and myelination, alongside rapid development in motor, linguistic, and social behavioral abilities. Understanding the relationship between brain development and behavioral…

Each language has its unique way to mark grammatical information such as gender, number and tense. For example, English marks number and tense/aspect information with morphological suffixes (e.g., -"s" or -"ed"). These morphological suffixes are crucial for language acquisition as they are the basic building blocks of syntax,…

Infant-directed speech (IDS) is characterized by a range of register-typical characteristics. Many of those can be objectively measured, such as acoustic-prosodic and structural-linguistic modifications. Perceived vocal affect, however, is a socio-emotional IDS characteristic and is subjectively assessed. Vocal affect goes beyond acoustic-prosodic…

Recent studies have found that infants show relational learning in the first year. Like older children, they can abstract relations such as "same" or "different" across a series of exemplars. For older children, language has a major impact on relational learning: labeling a shared relation facilitates learning, while labeling…

The goal of this intensive longitudinal study was to trace the developmental trajectories of infant pointing production, through consideration of the modality (i.e. pointing alone vs pointing-vocal coupling) and the communicative intention (i.e. imperative vs declarative). Multilevel analysis was used to model the normative trend and the…

This paper examines the acquisition of demonstratives (e.g., "that," "there") from a cross-linguistic perspective. Although demonstratives are often said to play a crucial role in L1 acquisition, there is little systematic research on this topic. Using extensive corpus data of spontaneous child speech, the paper investigates…

Around their first birthdays, infants begin to point, walk, and talk. These abilities are appreciable both by researchers with strictly standardized criteria and caregivers with more relaxed notions of what each of these skills entails. Here, we compare the onsets of these skills and links among them across two data collection methods: observation…

The ability to map similar sounding words to different meanings alone is far from enough for successful speech processing. To overcome variability in the speech signal, young learners must also recognize words across surface variations. Previous studies have shown that infants at 14 months are able to use variations in word-internal cues (i.e.,…

Using a large sample of longitudinal assessment data from children in publicly funded infant/toddler care, preschool, and kindergarten (analytic N = 453,468), this study modeled language and literacy trajectories from early infancy through kindergarten for dual language learners (DLLs) from homes representing many different languages and their…

Purpose: We aimed to provide novel information on utterance duration as it relates to vocal type, facial affect, gaze direction, and age in the prelinguistic/early linguistic infant. Method: Infant utterances were analyzed from longitudinal recordings of 15 infants at 8, 10, 12, 14, and 16 months of age. Utterance durations were measured and coded…

Social feedback is a driving force for speech development. A recent study provided a key finding to explain how contingent responses influence developmental change: infant speech-related vocalizations are contingent on responses to prior speech-related vocalizations (Warlaumont "et al.," 2014). However, the study did not distinguish…

The association between developmental trajectories of language-related white matter fiber pathways from 6 to 24 months of age and individual differences in language production at 24 months of age was investigated. The splenium of the corpus callosum, a fiber pathway projecting through the posterior hub of the default mode network to occipital…