Nicole Altvater-Mackensen

Word‐form familiarity bootstraps infant speech segmentation

At about 7 months of age, infants listen longer to sentences containing familiar words - but not deviant pronunciations of familiar words (Jusczyk & Aslin, 1995). This finding suggests that infants are able to segment familiar words from fluent speech and that they store words in sufficient phonological detail to recognize deviations from a familiar word. This finding does not examine whether it is, nevertheless, easier for infants to segment words from sentences when these words sound similar to familiar words. Across three experiments, the present study investigates whether familiarity with a word helps infants segment similar-sounding words from fluent speech and if they are able to discriminate these similar-sounding words from other words later on. Results suggest that word-form familiarity may be a powerful tool bootstrapping further lexical acquisition.

Children's altruistic behavior in context: The role of emotional responsiveness and culture

Altruistic behavior in humans is thought to have deep biological roots. Nonetheless, there is also evidence for considerable variation in altruistic behaviors among individuals and across cultures. Variability in altruistic behavior in adults has recently been related to individual differences in emotional responsiveness to fear in others. The current study examined the relation between emotional responsiveness (using eye-tracking) and altruistic behavior (using the Dictator Game) in 4 to 5-year-old children (N = 96) across cultures (India and Germany). The results revealed that increased altruistic behavior was associated with a greater responsiveness to fear faces (faster fixation), but not happy faces, in both cultures. This suggests that altruistic behavior is linked to our responsiveness to others in distress across cultures. Additionally, only among Indian children greater altruistic behavior was associated with greater sensitivity to context when responding to fearful faces. These findings further our understanding of the origins of altruism in humans by highlighting the importance of emotional processes and cultural context in the development of altruism.

A cross-linguistic perspective on the acquisition of manner of articulation contrasts in the productions of Dutch and German children

The present article investigates the acquisition of Manner of Articulation (MoA) contrasts in child language production. We analyzed spontaneous longitudinal speech data of four German and six Dutch 1- to 3-year-olds. The data suggest that the acquisition of MoA contrasts is influenced by various co-occurrence constraints at the word level. Interestingly, developmental patterns are very similar across languages. However, children seem to follow different strategies to introduce MoA contrasts: They either introduce MoA contrasts in word-initial position in monosyllables as well as in disyllables, or they introduce MoA contrasts in noninitial position in both types of words. We couch the data in a lexical framework assuming that early lexical representation fits templates that evolve in the course of development.

Neural correlates of infants’ sensitivity to vocal expressions of peers

Responding to others’ emotional expressions is an essential and early developing social skill among humans. Much research has focused on how infants process facial expressions, while much less is known about infants’ processing of vocal expressions. We examined 8-month-old infants’ processing of other infants’ vocalizations by measuring event-related brain potentials (ERPs) to positive (infant laughter), negative (infant cries), and neutral (adult hummed speech) vocalizations. Our ERP results revealed that hearing another infant cry elicited an enhanced negativity (N200) at temporal electrodes around 200 ms, whereas listening to another infant laugh resulted in an enhanced positivity (P300) at central electrodes around 300 ms. This indexes that infants’ brains rapidly respond to a crying peer during early auditory processing stages, but also selectively respond to a laughing peer during later stages associated with familiarity detection processes. These findings provide evidence for infants’ sensitivity to vocal expressions of peers and shed new light on the neural processes underpinning emotion processing in infants.

Phonological Features Mediate Object-Label Retrieval and Word Recognition in the Visual World Paradigm

While there are numerous studies that investigate the amount of phonological detail associated with toddlers’ lexical representations of words and their sensitivity to mispronunciations of these words, research has only recently begun to address the mechanisms guiding the use of this detail during word recognition. The current chapter reviews the literature on experiments using the visual world paradigm to assess infant word recognition, in particular, the amount of attention infants pay to phonological detail in word recognition. We further present data from a novel study using a visual priming paradigm to assess the extent to which toddlers retrieve sub-phonemic detail during lexical access. The results suggest that both the retrieval of an object’s label and toddlers’ recognition of a word involve activation of not only phonemic but also sub-segmental information associated with the lexical representation of this word. We therefore conclude that lexical access in toddlers is mediated by sub-phonemic information.