Research

The major thrusts of my research are:

• Speech Perception and Spoken Word Recognition. How do typical adults comprehend spoken language? How do they deal with the immense variability that characterizes the acoustic input? How do they deal with the temporal nature of the input as it unfolds over time? To address these questions we use a variety of behavioral techniques including eye-tracking along with phonetic analyses to precisely characterize the speech signal, computational models to investigate theoretical models of perception, and cognitive neuroscience to examine early auditory processes.
  
  
• Development of Speech Perception and Spoken Word Recognition. The development of speech perception and word recognition abilities is even more challenging. Children must confront all of the variability in the signal, while simultaneously learning the speech categories of their native language and the thousands of words of their language. To study this we conduct studies of speech perception and recognition in infants and children's, perform detailed phonetic analyses on caregivers' speech, and use computational models to understand theoretical models of learning.
  
  
• Word learning. Acquiring a lexicon is complex at several levels. Learners must acquire a complex temporal pattern of input (the word) and organize this material in a massive lexicon. However, they must also match these words to potential referents and/or meanings often in the face of considerable ambiguity as to what a novel word might mean. To investigate these issues, we perform studies with both children and adults and use extensive computational modeling.
  
  
• Language and Communication Disorders.While researchers often assume that most people eventually learn to recognize speech and use langauge equally well, for a substantial number of people this is not true. About 10-12% of children can be diagnosed with language impairment or reading disability, and many people have hearing troubles that may impair their ability to perceive speech. Our lab is investigating the mechanisms by which people confronting communicative disorders percieve speech by applying our eye-tracking techniques to several populations including people with langauge impairment, and both children and adults who use cochlear implants.
  
  
• Auditory Cognitive Neuroscience. An understanding of the brain is essential to understanding congition, language and development. By investigating neural processes involved in these domains, we can test cognitive theories and isolate the substrates over which these processes occur. Our intiial work in this focused on event-related potentials (ERPS), but more recently we have begun collaborating with the Human Brain Research Lab to use electro-corticography with awake behaving people undergoing treatment for epilepsy. We also have begun collaborating with the department of Neurology to examine people with various forms of brain damage.
  
  
• Other domains of Cognition and Perception. In addition to these issues, my lab seeks to generalizes the principles we have discovered in speech and word learning to new domains. In this light, we have studied a diverse set of topics including music perception, motor control, color perception, visual categorization, and even sleep in a variety of research subjects including infants, humans, pigeons and rats.