RESEARCH : The Big Questions

The research in my lab is concerned with delineating the neural basis of language and the processes and mechanisms involved in speaking and understanding. Particular focus of the lab is on speech, lexical processing, and the interface between sound structure and the lexicon. We are interested in the processes involved in how the continuous acoustic signal is transformed by perceptual and neural mechanisms into the sound structure of language, how sound structure of language maps on to lexical form (the mental dictionary), and how the mental dictionary is organized for the purposes of language comprehension and production.. Conversely, we are interested in the processes involved in the mapping from conceptual representations to lexical form and how lexical form ultimately interfaces with speech planning and ultimately articulatory implementation. We use a number of experimental paradigms including eyetracking, categorization and discrimination, priming, and acoustic analysis of speech production.

Broad questions that the lab is currently working on include:

• how does competition at various levels of the linguistic grammar (phonetics, phonology, lexical, semantic) influence processing? What are the neural systems underlying competition? Are the same neural systems recruited irrespective of the level of the grammar at which competition arises?
• to what extent does competition at one level of the grammar affect processing at other levels of the grammar? In other words, to what extent is language interactive and what are the neural substrates of these interactive processes? To what extent is word recognition and speech perception influenced by top-down processes?
• How do listeners perceive a stable phonetic percept despite the many sources of variability, e.g. vowel context, phonetic position, speaking rate? How does our perceptual and neural system 'know' that some differences matter, i.e. when a difference changes the phonetic category and other differences do NOT matter, i.e. when a difference does not change the phonetic category?
• How do we learn phonetic categories? To what extent do the statistics of the input shape the structure of the phonetic category? How does the neural system respond to differences in these properties as people learn a new phonetic category?