It's Mine, . . . It's Mine: Unsolicited Repetitions Are Reduced in Toddlers.

A phenomenon called "repetition reduction" can increase articulation rate in adults by facilitating phonetic and motor processes, which indicates flexibility in the control of articulation rate. Young children, who speak much slower, may not have the same speech motor flexibility resulting in the absence of the repetition reduction effect. In this study, we tested whether spontaneous repetitions of young children are produced with a faster articulation rate than their original utterances.

Early Speech Rate Development: A Longitudinal Study.

Purpose Our knowledge of speech rate development remains inadequate because of limited longitudinal data and lack of data from children under age 3;0 (years;months). The purpose of this longitudinal study was to test the pattern of speech rate development between ages 2;0 and 3;0. Method Speech rate was assessed at 4 time points between ages 2;0 and 3;0.

Quantum critical behaviour at the many-body localization transition.

Phase transitions are driven by collective fluctuations of a system's constituents that emerge at a critical point. This mechanism has been extensively explored for classical and quantum systems in equilibrium, whose critical behaviour is described by the general theory of phase transitions. Recently, however, fundamentally distinct phase transitions have been discovered for out-of-equilibrium quantum systems, which can exhibit critical behaviour that defies this description and is not well understood.

Probing entanglement in a many-body-localized system.

An interacting quantum system that is subject to disorder may cease to thermalize owing to localization of its constituents, thereby marking the breakdown of thermodynamics. The key to understanding this phenomenon lies in the system's entanglement, which is experimentally challenging to measure. We realize such a many-body-localized system in a disordered Bose-Hubbard chain and characterize its entanglement properties through particle fluctuations and correlations.

The Sequential Unfolding of First Phase Syntax: Tutorial and Applications to Development.

Purpose This tutorial is an introduction to first phase syntax (FPS; Ramchand, 2008 ). FPS provides a new, cross-linguistically motivated perspective on clause internal structure. A new sequence of syntactic development is proposed based on FPS with 4 levels of complexity: (0) verb particles and adjectives in the 1-word stage, (1) semantic relations of entity + location/attribution, (2) intransitive structures encoding change of location/state, and (3) transitive sentences with an internal argument that changes state/location and an external, causer argument.

Let's Be Explicit About the Psycholinguistic Bases of Developmental Measures: A Response to Leonard, Haebig, Deevy, and Brown (2017).

Purpose: The purpose of this letter is to clarify the psycholinguistic underpinnings of the tense marker total and tense agreement productivity score and to extend the discussion of when composite diversity and productivity measures are best used.

Conclusion: We encourage the use of composite diversity and productivity measures when assessing grammar early in development, but we discourage the use of composite accuracy measures until children demonstrate emergence of diverse tense/agreement morphemes across a sufficient number of low-frequency sentence frames.

Sentence Diversity in Early Language Development: Recommendations for Target Selection and Progress Monitoring.

Purpose: This clinical focus article describes how to assess and when to target diverse, simple sentences as part of early language intervention.

Method: The theoretical foundations and clinical motivations for assessing sentence diversity based on unique combinations of subjects and verbs are explained, followed by a description of how to compute the measure. Sentence diversity is then related to familiar developmental measures of lexical diversity, utterance length, and grammatical complexity in a sample of 40 typically developing toddlers at 30 months of age.

Changing the Subject: The Place of Revisions in Grammatical Development.

Purpose: This article focuses on toddlers' revisions of the sentence subject and tests the hypothesis that subject diversity (i.e., the number of different subjects produced) increases the probability of subject revision.

Input Subject Diversity Accelerates the Growth of Tense and Agreement: Indirect Benefits From a Parent-Implemented Intervention.

Purpose: This follow-up study examined whether a parent intervention that increased the diversity of lexical noun phrase subjects in parent input and accelerated children's sentence diversity (Hadley et al., 2017) had indirect benefits on tense/agreement (T/A) morphemes in parent input and children's spontaneous speech.

Method: Differences in input variables related to T/A marking were compared for parents who received toy talk instruction and a quasi-control group: input informativeness and full is declaratives.

Microscopy of the interacting Harper-Hofstadter model in the two-body limit.

The interplay between magnetic fields and interacting particles can lead to exotic phases of matter that exhibit topological order and high degrees of spatial entanglement. Although these phases were discovered in a solid-state setting, recent innovations in systems of ultracold neutral atoms-uncharged atoms that do not naturally experience a Lorentz force-allow the synthesis of artificial magnetic, or gauge, fields. This experimental platform holds promise for exploring exotic physics in fractional quantum Hall systems, owing to the microscopic control and precision that is achievable in cold-atom systems.

Input Subject Diversity Enhances Early Grammatical Growth: Evidence from a Parent-Implemented Intervention.

Purpose: The current study used an intervention design to test the hypothesis that parent input sentences with diverse lexical noun phrase (NP) subjects would accelerate growth in children's sentence diversity.

Method: Child growth in third person sentence diversity was modeled from 21 to 30 months ( = 38) in conversational language samples obtained at 21, 24, 27, and 30 months. Treatment parents ( = 19) received instruction on strategies designed to increase lexical NP subjects (e.

Quantum thermalization through entanglement in an isolated many-body system.

Statistical mechanics relies on the maximization of entropy in a system at thermal equilibrium. However, an isolated quantum many-body system initialized in a pure state remains pure during Schrödinger evolution, and in this sense it has static, zero entropy. We experimentally studied the emergence of statistical mechanics in a quantum state and observed the fundamental role of quantum entanglement in facilitating this emergence.

Ultra-precise holographic beam shaping for microscopic quantum control.

High-resolution addressing of individual ultracold atoms, trapped ions or solid state emitters allows for exquisite control in quantum optics experiments. This becomes possible through large aperture magnifying optics that project microscopic light patterns with diffraction limited performance. We use programmable amplitude holograms generated on a digital micromirror device to create arbitrary microscopic beam shapes with full phase and amplitude control.

Toddlers' Verb Lexicon Diversity and Grammatical Outcomes.

Purpose: The goals of this study were to quantify longitudinal expectations for verb lexicon growth and to determine whether verb lexicon measures were better predictors of later grammatical outcomes than noun lexicon measures.

Method: Longitudinal parent-report measures from the MacArthur-Bates Communicative Development Inventory (Fenson et al., 2007) from ages 21 to 30 months from an archival database were used to model growth in common noun and verb lexicon size for 45 typically developing toddlers.

Diversity matters: parent input predicts toddler verb production.

The contribution of parent input to children's subsequent expressive verb diversity was explored in twenty typically developing toddlers with small verb lexicons. Child developmental factors and parent input measures (i.e.

Measuring entanglement entropy in a quantum many-body system.

Entanglement is one of the most intriguing features of quantum mechanics. It describes non-local correlations between quantum objects, and is at the heart of quantum information sciences. Entanglement is now being studied in diverse fields ranging from condensed matter to quantum gravity.

Strongly correlated quantum walks in optical lattices.

Full control over the dynamics of interacting, indistinguishable quantum particles is an important prerequisite for the experimental study of strongly correlated quantum matter and the implementation of high-fidelity quantum information processing. We demonstrate such control over the quantum walk-the quantum mechanical analog of the classical random walk-in the regime where dynamics are dominated by interparticle interactions. Using interacting bosonic atoms in an optical lattice, we directly observed fundamental effects such as the emergence of correlations in two-particle quantum walks, as well as strongly correlated Bloch oscillations in tilted optical lattices.

Growth of finiteness in the third year of life: replication and predictive validity.

Purpose: The authors of this study investigated the validity of tense and agreement productivity (TAP) scoring in diverse sentence frames obtained during conversational language sampling as an alternative measure of finiteness for use with young children.

Method: Longitudinal language samples were used to model TAP growth from 21 to 30 months of age for 37 typically developing toddlers. Empirical Bayes (EB) linear and quadratic growth coefficients and child sex were then used to predict elicited grammar composite scores on the Test of Early Grammatical Impairment (TEGI; Rice & Wexler, 2001) at 36 months.

Are some parents' interaction styles associated with richer grammatical input?

Purpose: Evidence for tense marking in child-directed speech varies both across languages ( Guasti, 2002; Legate & Yang, 2007) and across speakers of a single language ( Hadley, Rispoli, Fitzgerald, & Bahnsen, 2011). The purpose of this study was to understand how parent interaction styles and register use overlap with the tense-marking properties of child-directed speech. This study investigated how parent interaction style, measured by utterance function, and parent register use when asking questions interacted with verb forms in child-directed input to identify interaction styles associated with the richest grammatical input.

Sequence and system in the acquisition of tense and agreement.

Purpose: The relatedness of tense morphemes in the language of children younger than 3 years of age is a matter of controversy. Generativist accounts predict that the morphemes will be related, whereas usage-based accounts predict the absence of relationships. This study focused on the increasing productivity of the 5 morphemes in the tense productivity score (copula BE, third-person singular present - 3s, past - ed, auxiliary DO, auxiliary BE; Hadley & Short, 2005) and their relationship to one another.

Predictors of morphosyntactic growth in typically developing toddlers: contributions of parent input and child sex.

Purpose: Theories of morphosyntactic development must account for between-child differences in morphosyntactic growth rates. This study extends Legate and Yang's (2007) theoretically motivated cross-linguistic approach to determine if variation in properties of parent input accounts for differences in the growth of tense productivity.

Method: Fifteen toddlers (and parents) participated.

The growth of tense productivity.

Purpose: This study tests empirical predictions of a maturational model for the growth of tense in children younger than 36 months using a type-based productivity measure.

Method: Caregiver-child language samples were collected from 20 typically developing children every 3 months from 21 to 33 months of age. Growth in the productivity of tense morphemes, centered at 21 months, was examined using hierarchical linear modeling.

Stalls and revisions: a developmental perspective on sentence production.

Purpose: The purpose of this research was to test the empirical validity of the stall-revision distinction and to provide a characterization of the development of sentence production using this distinction.

Method: The stall-revision dichotomy for sentence disruptions was studied in 20 typically developing children. The children's production of short sentences was observed from 21 to 33 months of age.

When children reach beyond their grasp: why some children make pronoun case errors and others don't.

This research addresses the question of why some children are disposed to making a large number of pronoun case errors and others are not. The answer proposed is that when pronoun paradigm building outstrips the development of INFL, children become especially vulnerable to erring in the choice of pronominal word form, resulting in pronoun case error. On the other hand, when pronoun paradigm building proceeds more conservatively, the risk of error is reduced.