Our research focuses on a central theme: what happens to the brain and behavior when development differs from the norm, and how can the course and outcome of that atypical development shed light on basic principles of developmental change? One important line of work in the laboratory investigates cross-modal plasticity, specifically how and whether the visual modality adapts to compensate for the absence of auditory input and experience. In these studies, hearing and deaf individuals of the same age perform tasks in which they attend to and respond to particular visual information, such as random-dot motion, color, or faces. The aim is to document what visual functions are affected by auditory deprivation (or the use of a signed language), and when in development these effects can be observed. Past research has shown that deaf individuals are faster and/or more accurate in responding to motion and produce larger ERPs and fMRI signals than hearing individuals, but that deaf and hearing individuals produce similar responses to color stimuli. This suggests that visual compensation is not global and may be specific to certain functions and/or visual pathways. Recent work shows that this population difference emerges during elementary school years, which suggests that the compensation is a product of cumulative visual experience in the absence of auditory input. This research program has important implications for understanding how intrinsic maturational timetables and extrinsic experiential factors interact across the course of development to influence the structure and function of brain and behavior.

One hypothesis as to why compensatory effects might be specific to some processes/systems and not others is that those processes and systems that take longer to develop may be more affected by atypical input or experience than those that develop faster. For example, is visual compensation for deafness specific to motion but not color processing because motion processing and its neural substrate take longer to develop than color processing? Developmental ERP studies by us and our colleagues suggest that this is so. In the Perceptual Development Lab, we are pursuing a line of research in which we test the hypothesis that slower developing aspects of face processing, some of which do not reach adult-like levels until the early 20s, may be enhanced as a result of auditory deprivation and/or the use of a signed language.

Three major techniques are used in the laboratory:

1. Behavioral measures such as reaction time and accuracy
2. Event-related potentials (ERPs), or the recording of the brain’s electrical activity in response to the stimuli and tasks
3. Functional MRI, which tracks changes in the flow of oxygenated blood throughout the brain in response the stimuli and tasks