The Petersen and Schlaggar Labs

The Petersen & Schlaggar Laboratories reside in the Mallinckrodt Institute of Radiology which is located in the East Building on the Washington University Medical School campus (for a map click here). The Petersen and the Schlaggar Laboratory have considerable overlap in research interests and share lab space. Both use behavioral and functional neuroimaging techniques (fMRI) to study the neural mechanisms underlying attention, language, learning and memory. Currently, there are two main areas of interest.

The first focus is on the normal and abnormal development of language. Methods have been, and are being developed to allow direct statistical comparison of child and adult imaging data. Both anatomical and functional studies show that this is possible using methods commonly applied to adult groups. Using these methods, we are currently comparing normal children and adults performing simple single-word processing tasks while being imaged. From these studies, it appears that while there is much similarity in images between adults and children, there are several systematic differences. Current studites include extending the age range of study (both older and younger), and to extend this study to children who have had early brain injury that either does or does not affect their subsequent ability to use language.

The other area of interest is in identifying fMRI signals related to different aspects of task organization. These processes might produce several different types of task-related signals including: 1) a task implementation process that might produce signals only at the beginning of the performance of a specific task 2) several processes that would span trials of a task and would be expected to produce prolonged fMRI signals (including biasing signals that provide input to specific pathways and might modulate item or trial based activity) as well as 3) signals related to each trial of a task. Certain patterns of results might be expected: 1) Some brain regions could show "task-related" signals in a broad range of tasks, and potentially could be related to more central executive processes such as the buffering of task demands. 2) Other regions might show task related effects specific to particular task domains, and be providing biasing signals for the selection of task-specific pathways. 3) Some regions might show transient signals at the beginning of a series of trials of a particular task, and may reflect task implementation. 4) Some regions might show a combination of task- and item/trial-related signals, and may be sites where top-down biasing signals interact with bottom-up processes. The experiments in this area of interest will survey several task domains within memory with the purpose of providing an empirical base for understanding signals related to task organization.