Alissa L. Ferry

The ability to compare plays a key role in how humans learn, but words that describe relations between objects, like comparisons, are difficult to learn. We examined how children learn size comparison words, and how their interpretations of these change across development. One-hundred-and-forty children in England (36–107 months; 68 girls; majority White) were asked to build block structures that were bigger, longer, smaller, shorter, or taller than an experimenter's. Children were most successful with words that refer to size increases. Younger children were less accurate with smaller and shorter, often building bigger structures. The dimensional aspect of taller emerged gradually. These findings suggest that children's interpretation of the meaning of size comparison words changes and becomes more precise across development.

During language acquisition children generalise at multiple layers of granularity. Ambridge argues that abstraction-based accounts suffer from lumping (over-general abstractions) or splitting (over-precise abstractions). Ambridge argues that the only way to overcome this conundrum is in a purely exemplar/analogy-based system in which generalisations are based on similarity to individual exemplars. However, to move our understanding forward, radical exemplar theory must include clearly specified mechanisms for analogy and similarity computation, and must account for changes in children’s generalisations across development.

To learn a language infants must learn to link arbitrary sounds to their meaning. While words are the clearest example of this link, they are not the only component of language; morphological regularities (e.g., the plural -s suffix in English) carry meaning as well. Comprehensive theories of language acquisition must account for how infants build links between these other parts of language and their meaning. Here, we investigated the acquisition of morphology in infants learning Italian, a language with a rich inflectional morphology that marks both gender and number on both the article and final vowel of nouns. We demonstrate that infants can build these links between concepts and morphological regularities much earlier than previously thought. Italian-learning 12-18- and 24-month-olds were shown pairs of images of faces that differed either in number (1 female vs. 2 females; 1 male vs. 2 males) or gender (1 female vs. 1 male; 2 females vs. 2 males). On each trial infants were directed to look at one of the images with the morphological regularities as the only distinguishing cue. Overall, across all ages, the infants looked to the labeled image, indicating that they had at least some understanding of the morphology. While infants succeeded on both gender comparisons, they only showed evidence of understanding the feminine number distinction. These results indicate that in the early stages of language acquisition, infants are able to identify recurring morphemes and to map those morphological regularities to the concepts that they mark in the language. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Before infants can learn words, they must identify those words in continuous speech. Yet, the speech signal lacks obvious boundary markers, which poses a potential problem for language acquisition (Swingley,Philos Trans R Soc Lond. Series B, Biol Sci364(1536), 3617–3632, 2009). By the middle of the first year, infants seem to have solved this problem (Bergelson & Swingley,Proc Natl Acad Sci109(9), 3253–3258, 2012; Jusczyk & Aslin, Cogn Psychol29, 1–23, 1995), but it is unknown if segmentation abilities are present from birth, or if they only emerge after sufficient language exposure and/or brain maturation. Here, in two independent experiments, we looked at two cues known to be crucial for the segmentation of human speech: the computation of statistical co‐occurrences between syllables and the use of the language's prosody. After a brief familiarization of about 3 min with continuous speech, using functional near‐infrared spectroscopy, neonates showed differential brain responses on a recognition test to words that violated either the statistical (Experiment 1) or prosodic (Experiment 2) boundaries of the familiarization, compared to words that conformed to those boundaries. Importantly, word recognition in Experiment 2 occurred even in the absence of prosodic information at test, meaning that newborns encoded the phonological content independently of its prosody. These data indicate that humans are born with operational language processing and memory capacities and can use at least two types of cues to segment otherwise continuous speech, a key first step in language acquisition.

Near-infrared spectroscopy (NIRS) is an optical technique offering a noninvasive and safe method to study the human brain, allowing both a functional approach and the evaluation of its optical (absorption and reduced scattering coefficients μa and μs′, respectively) or physiological baseline characteristics. Since Jöbsis1 demonstrated that, by exploiting the transparency of biological media to the near-infrared light, it was possible to assess the oxygenation of cerebral tissues, an increasing interest has been focused on the use of NIRS for adult and infant brain measurements.2 In fact, if one considers the hemoglobin as the main absorbing chromophore at the operating wavelengths, the information about oxy- and deoxyhemoglobin concentrations (cO2Hb and cHHb, respectively) inside a tissue can be easily derived from the measurement of its absorption properties. Furthermore, because the light diffuses inside tissues, measurements in reflectance configuration are possible, making feasible a flexible and experiment-designed configuration of optodes.

Experience puts people in touch with nonsolid substances, such as water, blood, and milk, which are crucial to survival. People must be able to understand the behavior of these substances and to differentiate their properties from those of solid objects. We investigated whether infants represent nonsolid substances as a conceptual category distinct from solid objects on the basis of differences in cohesiveness. Experiment 1 established that infants can distinguish water from a perceptually matched solid and can correctly predict whether the item will pass through or be trapped by a grid. Experiments 2 and 3 showed that infants extend this knowledge to less familiar granular substances. These experiments indicate that concepts of cohesive and noncohesive material appear early in development, apply across several types of nonsolid substances, and may serve as the basis of later knowledge of physical phases.

This research asks whether analogical processing ability is present in human infants, using the simplest and most basic relation—the same–different relation. Experiment 1 (N = 26) tested whether 7- and 9-month-olds spontaneously detect and generalize these relations from a single example, as previous research has suggested. The attempted replication failed. Experiment 2 asked whether infants could abstract the relation via analogical processing (Experiment 2, N = 64). Indeed, with four exemplars, 7- and 9-month-olds could abstract the same–different relation and generalize it to novel pairs. Furthermore, prior experience with the objects disrupted learning. Facilitation from multiple exemplars and disruption by individual object salience are signatures of analogical learning. These results indicate that analogical ability is present by 7 months.

To understand language, humans must encode information from rapid, sequential streams of syllables – tracking their order and organizing them into words, phrases, and sentences. We used Near‐Infrared Spectroscopy (NIRS) to determine whether human neonates are born with the capacity to track the positions of syllables in multisyllabic sequences. After familiarization with a six‐syllable sequence, the neonate brain responded to the change (as shown by an increase in oxy‐hemoglobin) when the two edge syllables switched positions but not when two middle syllables switched positions (Experiment 1), indicating that they encoded the syllables at the edges of sequences better than those in the middle. Moreover, when a 25 ms pause was inserted between the middle syllables as a segmentation cue, neonates’ brains were sensitive to the change (Experiment 2), indicating that subtle cues in speech can signal a boundary, with enhanced encoding of the syllables located at the edges of that boundary. These findings suggest that neonates’ brains can encode information from multisyllabic sequences and that this encoding is constrained. Moreover, subtle segmentation cues in a sequence of syllables provide a mechanism with which to accurately encode positional information from longer sequences. Tracking the order of syllables is necessary to understand language and our results suggest that the foundations for this encoding are present at birth.

Language is a signature of our species and our primary conduit for conveying the contents of our minds. The power of language derives not only from the exquisite detail of the signal itself but also from its intricate link to human cognition. To acquire a language, infants must identify which signals are part of their language and discover how these signals are linked to meaning. At birth, infants prefer listening to vocalizations of human and nonhuman primates; within 3 mo, this initially broad listening preference is tuned specifically to human vocalizations. Moreover, even at this early developmental point, human vocalizations evoke more than listening preferences alone: they engender in infants a heightened focus on the objects in their visual environment and promote the formation of object categories, a fundamental cognitive capacity. Here, we illuminate the developmental origin of this early link between human vocalizations and cognition. We document that this link emerges from a broad biological template that initially encompasses vocalizations of human and nonhuman primates (but not backward speech) and that within 6 mo this link to cognition is tuned specifically to human vocalizations. At 3 and 4 mo, nonhuman primate vocalizations promote object categorization, mirroring precisely the advantages conferred by human vocalizations, but by 6 mo, nonhuman primate vocalizations no longer exert this advantageous effect. This striking developmental shift illuminates a path of specialization that supports infants as they forge the foundational links between human language and the core cognitive processes that will serve as the foundations of meaning.