# Age of acquisition effects on sign language development and brain processing

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2020 · $637,695

## Abstract

Project Summary
Age of acquisition effects on sign language development and brain processing
Age of first-language age of acquisition, L1 AoA, has lifelong effects on language abilities and brain language
processing. Infants born deaf often first experience language at a variety of ages due to an inability to
perceive spoken language and not being exposed to sign language until older ages. We use this naturally
occurring variation in L1 AoA to model the critical period for language. In a series of studies, ask what the
language and neural correlates of the critical period might be. We test the hypothesis the organization of the
brain language system is an emergent property arising from interactive effects between language experience
and acquisition and post-natal brain growth. We test the hypothesis with two developmental paradigms,
retrospective and longitudinal. The retrospective studies test deaf adults whose ASL acquisition is complete.
These studies investigate whether L1 AoA effects between the ages of 1-8 are linear with respect to the level
of syntactic complexity acquired, the locus and distribution of neurolinguistic processing, and characteristics
of the dorsal and ventral white matter tracts. The longitudinal studies test deaf adolescents whose ASL
acquisition may be ongoing and whose L1 AoA began in infancy, or in early or late childhood. The
adolescents are tested annually for three consecutive years with same experiments as used in the adult
study. The language experiments are designed to test the comprehension and production of ASL sentence
structure as a function of syntactic complexity. The experimental paradigms are sentence-to-picture
matching, elicited imitation, syntactic priming, and spontaneous production. The neurolinguistic experiments
use fMRI to investigate sentence and lexical processing. The brain structure studies use DTI to investigate
dorsal and ventral white matter tract development. If the brain language system requires linguistic experience
during early post-natal brain growth to become fully functional, then levels of syntactic development should
correspond with the distribution and location of neurolinguistic processing in the brain as well as with the
robustness of white matter tract development in the brain language network.

## Key facts

- **NIH application ID:** 9828633
- **Project number:** 5R01DC012797-07
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Rachel I Mayberry
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $637,695
- **Award type:** 5
- **Project period:** 2012-12-01 → 2023-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9828633

## Citation

> US National Institutes of Health, RePORTER application 9828633, Age of acquisition effects on sign language development and brain processing (5R01DC012797-07). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9828633. Licensed CC0.

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