Mission and Approach
The research in the Woldorff Lab at Duke is aimed
toward the elucidation of the neural and psychological mechanisms
underlying human perception and cognition, with particularly strong
interests in the mechanisms of auditory and visual attention and
perception.
To study these phenomena we use various brain imaging techniques,
principally event-related potentials (ERPs) and functional MRI (fMRI),
along with concomitant recording of behavioral measures. We also
have ongoing international collaborations with laboratories employing
whole-head magnetoencephalography (MEG).
Our general view is that each of the brain imaging methodologies
provides an important but incomplete measure of brain function and
activity, and that the most powerful approach is the combined application
of several of them. For
example, hemodynamic (i.e., blood-change based) measures of brain
activity (e.g., fMRI) are very good at showing which areas of the
brain are activated under one sort of a task versus another, or
even by one sort of event type vs. another, but they generally provide
temporal information only on the order of seconds. Since many perceptual,
attentional, and cognitive brain operations occur on the order of
tens or hundreds of milliseconds, fMRI (at least in its present
form) provides relatively little information on the time course
or sequence of the functional brain activations underlying such
operations.
ERPs and MEG, on the other hand, although they have substantially
coarser spatial resolution,
provide a millisecond-by-millisecond reflection of evoked brain
activity, thereby providing high resolution timing information.
In addition, anatomical MRI provides extremely high-resolution images
of the neuroanatomical structures of the brain. Thus, combining
these approaches holds the promise of revealing not only which neuroanatomical
structures are activated during various mental functions, but also
what the time course and sequence of these activations are. Such
4-D spatial / temporal information is critical to develop full-fledged
neural and cognitive models of brain function.
The study of attentional, perceptual, and other cognitive processes
using such a combined multi-methodological approach is the major
aim of our research. |