Laura-Ann Petitto

Laura-Ann Petitto is a cognitive neuroscientist and a developmental cognitive neuroscientist, known for her discoveries involving the language capacity of chimpanzees, the biological bases of language in humans, especially early language acquisition (be it language on the hands in signed language or the tongue in spoken language), and bilingualism and the bilingual brain. She is also known for her role in the creation of the new scientific discipline, called educational neuroscience. Petitto is a professor in the Department of Psychology at the University of Toronto. She is also the Director and Senior Scientist of The Genes, Mind, and fNIRS Brain Imaging Laboratory for Language, Bilingualism, and Child Development at the university's Scarborough Campus.

Education
Petitto received her Bachelor of Science degree in 1975 from Ramapo College of New Jersey while taking undergraduate classes and conducting cross-species language research with the chimpanzee “Nim Chimpsky” at Columbia University (New York City, New York). Petitto then conducted psycholinguistic research on American Sign Language (ASL) in the laboratory of Dr. Ursula Bellugi at The Salk Institute for Biological Studies (La Jolla, California), along with Linguist, Edward Klima, of the University of California, San Diego, where Petitto began graduate study in the Department of Linguistics (1976–1977). Petitto continued graduate study at New York University (Masters Degree, 1978, specializing in Rehabilitative Counseling Psychology and Deafness, 1977–1978). Petitto then researched the phonological structure of ASL in the “The Linguistics Research Laboratory” of Dr. William Stokoe at Gallaudet University in Washington, D.C. (1978–1979). In 1979, Petitto began graduate study at Harvard University (Department of Human Development and Psychology), with Drs. Roger Brown (primary Graduate Advisor) and Courtney Cazden (co-Advisor), receiving her Masters in 1981 and her Doctoral degree in March, 1984. Leaving Harvard in Fall, 1983, to take up her first faculty appointment at McGill University (Montreal, Quebec, Canada), Petitto won a John D. and Catherine T. MacArthur Foundation Postdoctoral Fellowship (to study with Dr. Ursula Bellugi and Dr. Elizabeth Bates).

Scientific Contributions
Petitto’s research and discoveries span several scientific disciplines. Her early work with Nim Chimpsky and her later work with humans, encompasses Anthropology, Comparative Ethology, Evolutionary Biology, Cognitive Neuroscience, Cognitive Science, Theoretical Linguistics, Philosophy, Psychology, Psycholinguistics, Language Acquisition, Child Development, Evolutionary Psychology, Deaf Studies, and Bilingualism. Her overall discoveries involve:(1) cross-species (apes and humans) language and cognitive capacities,(2) the nature of early human language acquisition, structure, and representation in the human brain,(3) the structure, grammar, and representation of natural signed languages of Deaf people, and(4) the nature of bilingual infants, children, and adults’ dual language and reading development, processing, and brain organization.

Petitto had a leading international role in the creation of a new scientific discipline that she and her colleagues have termed Educational Neuroscience, involving the marriage of basic scientific discoveries about the developing brain/child with its principled application to solving core problems in the education of young children. Taken together, the major contribution of her scientific writings have been to offer both testable hypotheses and theory regarding the neural basis for the brain’s specialization for human language, and how it is possible for very young babies to acquire language.

Early Research
Beginning in 1973 in the Department of Psychology at Columbia University, Petitto attempted to teach sign language to a baby chimpanzee ("Project Nim Chimpsky," named after Noam Chomsky, with Professors Herbert Terrace and Thomas Bever). Petitto had a leading role on Project Nim Chimpsky as the “Primary Sign Language Teacher,” “Project Coordinator,” and primary “Surrogate Mother.” Despite the dangers of living with a chimpanzee, Petitto lived with and cared for Nim as a child in an attempt to create a natural language, cognitive, and highly caring and rich social environment, mirroring that of a human child. Most all of the chimp’s scientific training and accomplishments were achieved during Petitto’s 4-year tenure on the Project as Nim’s teacher and caretaker. She and her colleagues have authored several of the world’s seminal scientific papers on the question of language in chimpanzees, including now classic articles on the similarities and differences between the ape and human mind.

After her undergraduate work with Nim Chimpsky, Petitto went on to make discoveries about the linguistic structure, acquisition, and representation in the brain of the world’s natural signed languages, especially American Sign Language (ASL). Using signed languages as a new “microscope” to discover the central/universal properties of human language in the brain (those that are distinct from the modality of language transmission and reception), Petitto advanced 4 branches of research. These include:(1) Universal Linguistic Structures (cross-linguistic studies of signed and spoken languages,  and cross-linguistic studies of different signed languages, especially ASL and Langue des Signes Québécoise, LSQ) (2) Linguistic Timing Milestones in Development (the highly similar maturational timing in the achievement of language milestones across young children acquiring spoken and signed languages),  (3) Universal Linguistic Structures in Development (the highly similar acquisition of specific parts of natural language structure, with similar timing and use, across signed and spoken languages). For example, similar Pronouns, Pronominal Reference, and Pronoun-Reversals, across young children acquiring spoken and signed languages, despite the radically different linguistic form of pronouns in signed languages. The discovery of rhythmically-alternating, phonetic-syllabic “manual Babbling” on the hands in babies acquiring signed languages (be they Deaf or hearing), identical in linguistic structure, timing, and use to vocal Babbling in hearing babies acquiring spoken languages. For decades, Babbling was viewed as inextricably tied to sound and speech. However, the discovery of hand Babbling demonstrated that rather than sound being key, Babbling reflects the infant’s biologically-given sensitivity to highly specific patterns that are part of language structure. The discovery forced a reconceptualization of the nature of human Language by decoupling Speech and Language. The discovery of manual Babbling was featured on both the cover of Science and the front page of the New York Times on the same day. (4) Distinct Knowledge Representation in Development (domain-specific versus domain-general knowledge in child development: the difference between language versus communicative gesture in all children’s development) (5) Brain Tissue Dedication for Aspects of Human Language Structure and Processing (convergences of specific linguistic functions on specific brain tissue across signed and spoken languages). For example, previously regarding spoken language, phonological processing was found to occur in the left hemisphere's (LH) Superior Temporal Gyrus (brain tissue regarded as unimodal sound processing tissue for 125 years), and the Left Inferior Frontal Cortex was regarded as the brain's site for the search and retrieval of information about word meanings (due to its proximity to LH speech production mechanisms). However, Petitto and her team found that the same brain tissue recruitment is used when processing the same parts of language regardless of whether the language was on the hands in signed language or the tongue in spoken language. Petitto is associated with advancing the new hypothesis that this brain tissue is not neurally set to sound but to specific patterns that are part of language structure, which corroborated her earlier infant manual babbling discoveries and moved beyond “where” language processing occurs in the human brain to explain the nature of its underlying neural basis. 

In addition to its scientific importance, Petitto’s research has contributed to the body of knowledge establishing that the signed languages of Deaf people around the world are real languages with the full expressive capacity as spoken languages. Petitto and colleagues were also the first to study experimentally the validity of a widely used educational practice with Deaf children in the 1970s, whereupon teachers (typically hearing) used parts of ASL signs and linguistic structure simultaneously while speaking English in the classroom, called “Simultaneous Communication” (or “Simcom”). The Petitto team’s experimental study of Simcom with Deaf children demonstrated empirically that it was highly impoverished at representing either ASL or English (and, in turn, was a non-optimal teaching method), and instead supported the use of a natural language with Deaf children from early life (such as ASL), which would best provide a solid linguistic foundation upon which to learn other languages (such as English) and advanced the idea that Deaf Education would be best to move closer to a full bilingual/bicultural educational model. This research had lasting implications for subsequent Deaf Education policy and practice.

Current Research
Petitto’s current studies involve the use of a combination of three disciplines:Genetic analyses (polymorphisms in candidate genes),Behavioral measures of higher cognitive processes from Psycholinguistics and Developmental Science, and <LI>Neuroimaging from Cognitive Neuroscience. Petitto and her team use a powerful new brain imaging technology, called functional Near Infrared Spectroscopy (fNIRS), a technology that she and her team have helped to pioneer.

Since 2000, Petitto and her laboratory team are known for discovering that young bilingual children are not harmed, delayed, or confused by early dual language exposure. These children, not only achieve their language milestones (in each language) on the same timetable as monolinguals, they demonstrate the same semantic and conceptual development as monolinguals. Petitto and her team have also identified the mechanisms that make possible the human infant’s early capacity to phonetically discriminate (segment and categorize) the constantly varying linguistic stream around them. Petitto has identified fundamental processes that underlie human reading and spelling in all language users and found evidence for select reading advantages in young bilingual children as compared to matched monolingual peers, termed the “bilingual reading advantage.” They have further discovered surprising ways in which bilingual schooling can ameliorate the deleterious effects of low SES They are also among the first group of researchers to compare directly adult bilingual and monolingual brains   and what happens when the adult brain learns two artificial languages as a second language.

Petitto and her team also conduct Genes, Behavior, and Brain studies of how extensive training (expertise) in one domain of knowledge impacts or “transfers” to other domains of knowledge (and the extent of this transfer). For example, Petitto studies how extensive training in the Arts impacts a young child’s acquisition of other knowledge, a question vital to Educational policy-makers with limited budgets. She and her team also study expert Performing Artists (e.g., Dancers) and the extent to which “expertise” of this type may transfer to “near” and “far” domains of knowledge.

Research Awards
Petitto is the recipient of over twenty international prizes and awards for her distinguished scientific achievements, including, for example,<LI>“Fellow” of the American Association for the Advancement of Science (AAAS). Elected October 2008. Presented at the Fellow Forum, 14 February 2009, Chicago. <LI>“Fellow” of the Association for Psychological Science (APS). December 2008. <LI>The Justine and Yves Sergent International Prize in Cognitive Neuroscience, Université de Montréal Honorary Diploma, Faculty of Medicine, Quebec, Canada, 2004<LI>Guggenheim Award (for her “unusually distinguished achievements in the past and exceptional promise for future accomplishment” in the discipline of Neuroscience), conferred in Spring, 1998<LI>Visiting Resident Scholar (1998–1999) in the Departments of Nuclear Medicine & Cognitive Science, at the Università & Ospedale Istituto San Raffaele, in Milan, Italy.<LI>Fellow (1991–1992) at the Center for Advanced Study in the Behavioral Sciences at Stanford University, Stanford, California (1991–1992) <LI>Visiting Resident Scholar (1987–1988) in the Department of Experimental Psychology, University of Cambridge, and the Medical Research Council (Speech and Language Group), in Cambridge, England, in conjunction with the Medical Research Council (Cognitive Development Unit), in London, England<LI>American Psychological Association Boyd R. McCandless “Young Scientist Award” (for “outstanding early career contributions to, and achievements in Developmental Psychology”), conferred at the APA Convention, Atlanta, GA., 1988,<LI>American Psychological Association “Young Psychologist Award,” conferred at the 24th International Congress of Psychology, Sydney, Australia, 1988</UL>