Word Learning in Bilingual Typical and Late Talking Children: The Role of Meaning and Input

NCT07600242 | Recruiting

• 1 other identifier: K23DC022006
• Study Type: interventional
• Target: 80
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this clinical trial is to understand how different types of word categories, along with the language children hear from their parents, support bilingual toddlers' word learning. This study will address two main questions: (1) How are the words toddlers know related to the words their parents use? and (2) How does what toddlers already know help them learn new words in two languages? The investigators will compare bilingual toddlers with typical development to those with language delay to determine whether they learn new words in similar ways. Children's vocabulary knowledge will be assessed using standardized parent-report checklists. To examine how different types of categories support learning, the study will focus on two early-acquired categories: animals and clothing. The investigators will compare what parents report about their children's vocabulary with how children learn new words within each category. To understand the role of parent input, children and their parents will engage in shared book reading and play activities using materials from one of the target categories. Parent-child interactions will be video recorded. Children will also complete an eye-tracking task in which they learn new words in two languages within the same category.

Conditions

Bilingualism; Vocabulary Acquisition; Late Talkers; Network Science

Keywords

bilingualism; late talkers; parent input; toddlers; word learning; vocabulary

Outcome Measures

Primary Outcomes (3)

• Word learning

  The researchers will assess learning through participants' looking behavior via experimental eye-tracking paradigms. Specifically, the researchers will measure how accurately and quickly participants look to the target object after hearing its name.

  Day 1

• Vocabulary Network Properties

  The researchers will characterize participants' vocabulary size and structure using the MacArthur-Bates Communicative Development Inventories (MB-CDI). Vocabulary size will be calculated using the raw number of words produced (range: 0-680 words) and their age-matched percentile score from the MB-CDI (range: 0-100). Higher scores indicate larger vocabulary sizes.The researchers will also calculate how many words each participant knows in in two categories on the MB-CDI (i.e., animals \[0-43 words\] and tools \[0-28 words\]) across the languages they are learning (i.e., English and Spanish). Network properties may include the number of words in a category and the number of connections between words in a category.

  Day 1

• Parent Language Input

  The researchers will calculate the number of words the parent says to their child during book reading and toy play activities. Language input will be defined as the total number of nouns and verbs (tokens) and the number of unique nouns and verbs (types).

  Day 1

Study Arms (2)

Toddlers with typical language development

EXPERIMENTAL

Children who have typical vocabulary sizes and do not have a history of hearing or vision impairment, neurodevelopmental disorders, or neurological or cognitive delays/disorders.

Behavioral: Large Semantic Category Condition; Behavioral: Small Semantic Category Condition

Toddlers with language delay

EXPERIMENTAL

Children whose vocabulary size is atypically small for their age in the absence of hearing impairment, neurodevelopmental disorders, or other cognitive delays.

Behavioral: Large Semantic Category Condition; Behavioral: Small Semantic Category Condition

Interventions

Large Semantic Category Condition BEHAVIORAL

Participants will learn new words that refer to objects that belong to a category from which toddlers know many words (i.e., animals). They will learn new animal words in two different language conditions: a single language context and a dual language context. In the single language context, they will learn new English-like words in a learning environment where they only hear one language (i.e., English). In the dual language context, they will learn new English-like and Spanish-like words in a learning environment where they only hear both languages. Participants and their parents will also read books about animals and play with animal toy sets.

Toddlers with language delay; Toddlers with typical language development

Small Semantic Category Condition BEHAVIORAL

Participants will learn new words that refer to objects that belong to a category from which toddlers know few words (i.e., clothing). They will learn new clothing words in two different language conditions: a single language context and a dual language context. In the single language context, they will learn new English-like words in a learning environment where they only hear one language (i.e., English). In the dual language context, they will learn new English-like and Spanish-like words in a learning environment where they only hear both languages. Participants and their parents will also read books about clothes and play with toy sets that include clothing.

Toddlers with language delay; Toddlers with typical language development

Eligibility Criteria

• Age: 24 Months - 30 Months
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• At least 10% exposure to both English and Spanish or at least 90% exposure to English and another language

You may not qualify if:

• Hearing impairment
• Uncorrected visual impairment
• Neurological impairment
• Genetic syndromes
• Neurodevelopmental disabilities (e.g. autism)
• More than 10% exposure to a language other than English or Spanish

Sponsors & Collaborators

• Boston University Charles River Campus: lead
• National Institute on Deafness and Other Communication Disorders (NIDCD): collaborator

Study Sites (1)

Boston University

Boston, Massachusetts, 02215, United States

RECRUITING

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: A mixed-factor design where each child will be randomly assigned to one of two word learning conditions (animal or clothing). Within each condition, children will learn words in single and dual language conditions. The clinical group (toddlers with late talking) is compared to the control group (toddlers with typical development) on these conditions.

Study Record Dates

• First Submitted: May 7, 2026
• First Posted: May 20, 2026
• Study Start: December 16, 2025
• Primary Completion (Estimated): July 31, 2028
• Study Completion (Estimated): July 31, 2029
• Last Updated: May 20, 2026

Record last verified: 2026-05

Locations

US (1)