Karin Stromswold - US grants

9875168
Stromswold

Some apparently normal children inexplicably have difficulty acquiring
language. Specific language impairment (SLI) is the term for severe
developmental delays in the production and/or comprehension of
language that do not seem to be due to hearing loss, mental
retardation, motor deficits, neurological or psychiatric disorders, or
lack of exposure to language. In this project, three types of studies
will be conducted on normally-developing and SLI children: 1) analyses
of longitudinal spontaneous speech samples; 2) analyses of
cross-sectional elicited speech samples; and 3) analyses of imitated
sentences that systematically vary in phonological, syntactic and
lexical complexity. Through careful analyses of these data, we will
address the following questions:

* What is the nature of the linguistic deficit(s) in SLI?
* To what extent are some components of language (e.g., syntax, phonology,
lexicon) spared relative to others in SLI?
* To what extent do performance factors play a role in SLI children's
deficits? To what extent does SLI and normal children's performance
on language tasks degrade as performance load increases?
* Do SLI and normal children have a single (limited) pool of performance
resources for all language tasks, or does each subcomponent of
language have its own dedicated resources? Does increased performance
load in one area of language lead to decreased performance in just
that area or in other areas of language as well?

Although many linguists argue that all languages share a common universal grammar, superficially languages vary tremendously. For example, some languages such as English allow only one basic word order (fixed word order languages), while languages such as Turkish permit many word orders. In addition, there are isolating languages such as Mandarin in which grammatical relationships are expressed through word order, and not by adding to or changing morphological structure of words, and languages such as Turkish in which grammatical relationships are expressed via sequences of inflectional particles, each of which expresses a specific grammatical meaning. Despite differences which exist among languages, most language acquisition research has concentrated on languages that are fixed word order and either isolating or inflecting. Investigations of agglutinative, free word order languages are necessary if we are to test explanatory and descriptive adequacy of theories of acquisition.

In this project we will use data from comprehension, imitation and judgment experiments to study the acquisition of Turkish as a first language by children between 1.5 and 6 years of age. These data will be used to address the following fundamental questions about language acquisition:

1. Are young children predisposed to assume that the language they are acquiring has a fixed word order?
2. Do they know the structural restrictions on a free word order language?
3. When do children start reconciling structural restrictions and discourse considerations in a free word order language?
4. Are young children predisposed to assume that grammatical particles are attached in a fixed order?
5. Do children acquire particles that are putatively part of a universal ordering earlier than particles that are not?

DESCRIPTION (Adapted from applicant's description): In this project the +___________ investigators will use spontaneous speech data and data from comprehension, imitation and judgment experiments to study the acquisition of Turkish as a first language by children between 1.5 and 6 years of age. These data will be used to address the following fundamental questions about language acquisition: 1. At what age do children begin to use functional category morphemes? 2. How productive is their early use of these morphemes? 3. Are young children predisposed to assume that the language they are acquiring has a fixed word order? 4. How do children learn to map words onto grammatical functions (e.g., subject, object)? 5. How do children learn to map these grammatical functions onto thematic roles? 6. Are young children predisposed to assume that grammatical particles are attached in a fixed order?

Between 5 to 10% of apparently normal children have difficulty acquiring written or spoken language. Twin studies are the most common type of study used to tease apart the impact of environmental and genetic factors on language development. Because identical twins share 100% of their alleles and fraternal twins share only 50% of their alleles, if identical twin pairs' linguistic abilities are more similar than fraternal twin pairs', this suggests that genetic factors play a role in language. Furthermore, the rate of language impairments and delays is twice as high for twins as singletons, probably reflecting pre- and postnatal environmental hazards associated with twinning. Thus, twin studies can be used to investigate how specific environmental factors affect language development.

This project will use longitudinal data from 450 twin pairs to investigate how genetic and prenatal and postnatal environmental factors affect linguistic and nonlinguistic development. The project will address the following key questions:
1. How great a role do genetic factors play in the linguistic and nonlinguistic development of linguistically normal and language-impaired children?
2. How specific to language (or subcomponents of language) are these genetic factors?
3. To what extent do prenatal and early postnatal environmental factors affect linguistic and nonlinguistic development?
4. How developmentally stable are the effects of these genetic and environmental factors?
5. How do interactions among environmental and genetic factors affect normal and language-impaired children's linguistic and non-linguistic development?
The direct and indirect costs of language-related learning disabilities are enormous to the impaired child, their family and society. This study may help uncover which environmental factors protect children from impairments and which increase their risk. This study may also provide needed insight into the ways in which genetic factors and environmental factors interact to raise or lower the risk of linguistic and nonlinguistic impairment. Armed with this knowledge, clinicians and teachers may be able to tailor therapeutic and educational practices so as to maximize each child's potential.

Strengthening American Infrastructure (SAI) is an NSF Program seeking to stimulate human-centered fundamental and potentially transformative research that strengthens America’s infrastructure. Effective infrastructure provides a strong foundation for socioeconomic vitality and broad quality of life improvement. Strong, reliable, and effective infrastructure spurs private-sector innovation, grows the economy, creates jobs, makes public-sector service provision more efficient, strengthens communities, promotes equal opportunity, protects the natural environment, enhances national security, and fuels American leadership. To achieve these goals requires expertise from across the science and engineering disciplines. SAI focuses on how knowledge of human reasoning and decision making, governance, and social and cultural processes enables the building and maintenance of effective infrastructure that improves lives and society and builds on advances in technology and engineering.

In 2020, many public spaces were hastily redesigned to optimize pedestrian flow in order to minimize the spread of COVID-19. Unfortunately, conventional methods for simulating how people move through public spaces do not take into account social factors that affect how people actually navigate in the presence of other people (social wayfinding). For example, these methods do not incorporate how people adjust to avoid others’ personal space, navigate around slower-moving people, or follow instructions from other people. Even worse, existing simulations usually assume everybody has identical abilities, which is rarely true in real populations. The goal of this project is to develop a system for simulating the flow of people through public spaces, including social aspects of human navigation, and incorporating people with a variety of abilities and disabilities. These more realistic simulations will be used to develop novel metrics and protocols for evaluating public spaces, which more thoroughly reflect the rich social behavior of real people.

This project develops a new framework for modeling the flow of people through public spaces, called the Social Wayfinding-Inspired InFrasTructure (SWIIFT) design framework. The framework has three interlocking parts: human subjects experiments on human wayfinding, computational simulations of the flow of people through public spaces, and evaluation metrics for assessing design and re-design of real public spaces. In a series of experiments, human subjects will be immersed via Virtual Reality headsets into simulated spaces. These spaces will contain different numbers of simulated people, including people with variations in mobility (using wheelchairs, canes or walkers; pushing strollers; carrying heavy bags), sensory ability (e.g., visual impairments, hearing impairments), knowledge, and attention. Human subjects will receive different cues about which way to go, including visible pathways, signage, and verbal instructions. Data about the choices they make as they navigate through the virtual spaces will be incorporated into simulations, allowing us to develop realistic models of how people move through spaces under natural conditions. Finally, this framework will use these simulation models to evaluate potential modifications to real spaces, allowing potentially expensive changes to be accurately evaluated before they are carried out. The ultimate goal of this work is to enable public spaces to be made more efficient and more accessible for everyone, regardless of ability.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.