Research in our Lab

Diffusion Model

See here for more about the diffusion model, here for information for non-specialists, and here for demonstrations.

Language Processing

We are currently funded by the Department of Education’s Institute for Educational Studies to examine the component processes of reading comprehension in struggling adult readers. Our research participants for these studies are adults of varying ages who have dropped out of high school and who read on a 4th to 9th grade level.

Aging and Development

Our grant from the National Institute on Aging currently funds research with older adults on simple two-choice decision making involving memory, speed of processing, perception, and driving. We also study these areas in children, expanding recently into issues of number processing.

Clinical and Neuropsychology

Our NIA grant work also focuses on methodological research on modeling techniques aimed toward developing comprehensive decision making models for neuropsychological testing.

Human Neuroscience

Through collaborations with researchers at the University of Amsterdam, Columbia University, Brown University, and other institutions, we apply the diffusion model to accuracy data and reaction time distributions in the neuroscience domain, to relate theoretical processes to issues such as brain area activation.

Applications

The diffusion model has been used to fit data from research in many applied domains, including:
aging
sleep deprivation
aphasia
hypoglycemia
anxiety and depression
children
neurophysiology
EEG
fMRI

Theory

Comparisons between individuals or groups of individuals usually focus on three main components of processing, identified by the diffusion model as drift rates, boundary settings, and nondecision times. Separating these three components means that within a task, it is possible that drift rates, boundary separation, and nondecision time do not correlate with each other. In other words, the values of none of the three components can be predicted from the values of either of the other two. The model allows determination of these components at the level of individuals and so can provide a picture of how the three components vary within and between age groups.