Naomi Caselli

Assistant Professor

Naomi Caselli studies the effects of limited language exposure on cognition in d/Deaf children. Her recent work explores the lasting effects of early language experience on the perception of sign language. She is the co-developer of ASL-LEX, a lexical database for American Sign Language published in Behavior Research Methods.

Prior to her doctoral studies at Tufts University, she earned an Ed.M. in Deaf Education and an M.A. in Psychology from Boston University. She also worked as a nationally certified ASL-English interpreter for nine years.

Find out more about Dr. Caselli’s grant-funded work investigating the relationship between language deprivation and the ASL lexicon on her LexLab website and ASL Vocabulary Acquisition Project site.


Chair of the Millie Brother Scholarship for Children of Deaf Adults.

Ph.D. in Psychology and Cognitive Science, Tufts University

M.A. in Psychology, Boston University

Ed.M. in Deaf Education, Boston University

B.A. in Liberal Arts, The Evergreen State College

SED DE552: Seminar: Selected Topics in Deaf Studies

SED DE691: Learning and the Deaf

SED DE574: Prepracticum: Initial Strategies

SED DE554: Field Experience: Deaf Studies

SED DE576: ASL Structure

Naomi Caselli studies the effects of language deprivation--limited language exposure during early childhood--on language acquisition and development of deaf children. She is particularly interested how people learn and use signs in American Sign Language (ASL). She currently directs the grant funded projects. The first is aimed at developing ASL-LEX, a lexical database for American Sign Language published in Behavior Research Methods. The second is aimed at understanding how the visual modality has shaped the ASL lexicon. The third is aimed at developing ASL vocabulary assessments for young children, and examining the factors that shape early vocabulary acquisition among deaf children who are and are not at risk for language deprivation.

ASL-LEX ( is a lexical database that catalogues information about signs in American Sign Language (Caselli, Sevcikova Sehyr, Cohen-Goldberg, & Emmorey, 2016). It currently includes information about frequency (how often signs are used in everyday conversation), iconicity (how much signs look like what they mean), and phonology (which handshapes, locations, movements etc. are used). Many deaf children in the US unfortunately do not know ASL. Teachers can use ASL-LEX to support vocabulary in deaf and students who are learning ASL (e.g., to develop vocabulary lessons that prioritize commonly used signs). Students can also look up signs based on their sign form, without knowing a sign’s English translation, and begin to learn about linguistic patterns in the forms of signs. It can also be used by ASL researchers to develop experiments. We are also using ASL-LEX to understand how the visual modality has shaped the ASL lexicon. These projects are supported by the National Science Foundation (1625793 and 1749384).

Many deaf children have limited access to language early in life: they often do not have signing role models, and cannot hear the sounds of spoken language. These children are at risk of incomplete acquisition of their first language; this is called language deprivation. My work explores the trajectory of vocabulary development in deaf children with or without language deprivation, because early vocabulary is a critical building block in language acquisition. The goal is to identify the signs that children learn, the factors that promote vocabulary acquisition (Caselli & Pyers, 2017), and to develop assessment tools for identifying children who have limited ASL vocabularies. With these tools in hand, researchers and educators will be better able to develop interventions to mitigate the effects of language deprivation. Find out more about this project. This project is supported by the National Institute of Deafness and other Communication Disorders (R21DC016104).

Visit Dr. Caselli's Faculty Profile
Visit Dr. Caselli's LexLab Website
Dr. Naomi Caselli awarded NIH grant to research language deprivation in deaf children
Research Update: Dr. Naomi Caselli’s Team Extends Investigation into Language Deprivation in Deaf Children

Caselli, N., Pyers, J. (in press). The road to language learning is not entirely iconic: Neighborhood density, iconicity, and frequency facilitate sign language acquisition. Psychological Science.

Caselli, N., Sevcikova Sehyr, Z., Cohen-Goldberg, A., Emmorey, K.  (2016). ASL-LEX: A Lexical Database for American Sign LanguageBehavior Research Methods.

Caselli, N., Caselli, M., Cohen-Goldberg, A. (2015). Inflected words in production: Evidence for a morphologically rich lexicon. Quarterly Journal of Experimental Psychology.

Caselli, N. & Cohen-Goldberg, A. (2014). Lexical access in sign language: A computational model. Frontiers in Psychology, 5.

Caselli, N., Ergin, R., Jackendoff, R., Cohen-Goldberg, A. (2015) Iconicity and Phonological Structure in Emerging Language. Contributed talk at the Emerging Sign Languages and the Big Picture Workshop, Medford, MA.

Caselli, N., Cohen-Goldberg, A. (2014) Lexical access in sign language: A computational model. Contributed talk at From Sound to Gesture, Padova, IT.

Koster-Hale, J., Caselli, N, Magid, R., Benedict, R, Pyers, J, and Saxe, R. (2014). Early childhood experience has long-lasting impact on the neural basis of theory of mind. Contributed talk at the annual conference of the Cognitive Science Society, Quebec, Canada.

Caselli, N., Cohen-Goldberg, A. (2014). Lexical access in sign language: A computational model. Poster presented at the Ninth International Conference on the Mental Lexicon, Niagara-on-the-lake, Ontario, CA.

Caselli, N., Caselli, M., Cohen-Goldberg, A. (2012). The contribution of root and word representations to phonological
processing of multimorphemic words. Contributed talk at the 13th Conference on Laboratory Phonology. Stuttgart, DE.

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