Programs:

Summary

My research seeks to use functional neuroimaging in conjunction with cognitive, motor, and emotional activation paradigms in novel ways to study cingulate cortex function in normal cognitive processing and neuropsychiatric disorders--especially attention-deficit/hyperactivity disorder (ADHD).

Determining the nature of cingulate sub-territories is vital to understanding the neurobiology of neuropsychiatric disorders, as cingulate subregions play crucial roles in cognitive, motor, and emotional processes. Many studies have reported cingulate activation as if it were a single homogeneous region, but to truly understand how cingulate cortex may be involved in neuropsychiatric disorders, the functions of its different subregions in normal humans must be determined. Anterior cingulate cortex (ACC) encompasses subdivisions that subserve distinct functions, including the cognitive/motor dorsal division (dACC), the emotional/affective divisions (rostral [rACC] and subgenual [sgACC]), and nociceptive areas. These sub-territories are distinguishable based upon cytoarchitectural and connectivity patterns, and convergent evidence from lesion studies, electrophysiology, and functional neuroimaging has strongly supported this functional division.

Using a battery of cognitive, motor, and emotional fMRI paradigms, I have been functionally dissecting cingulate cortex in individual humans. I first developed an fMRI Stroop task variant (the 'Counting Stroop') that activates the cognitive dACC. In one of the first fMRI studies of attention deficit hyperactivity disorder (ADHD), we used the Counting Stroop to show that the cognitive division is dysfunctional in ADHD patients. This task will soon be used in large-scale studies of ADHD. I also collaborated with Dr. Paul Whalen on creating the spin-off Emotional Counting Stroop, and with Dr. Lisa Shin, who used this task to study PTSD.

More recently, I created an improved task (the Multi-Source Interference Task, MSIT) that produces dACC fMRI activation reliably in individuals. In addition to its use in the recently completed validation study, this task is currently being used to study methylphenidate and placebo effects in adults with ADHD, and in numerous collaborative spin-offs to study children and adolescents with ADHD (Drs. Frazier and Ahn), schizophrenia (Dr. Heckers), early cognitive deficits of HIV+ infection (Drs. Stern and Searl), and Tourette's Syndrome (Dr. Deckersbach).

Finally, the MSIT will also soon be used to study Alzheimer's Disease and sleep disorders. Finally, I recently developed a local intracortical network model of the dACC (the "cognitive division") that is firmly rooted in the monkey single unit literature, and collaborated with internationally recognized cingulate and imaging experts on an event-related fMRI study that used a reward-based decision-making task to validate the model. This model can resolve existing discrepancies in the human functional imaging and electrophysiology literatures (detailed in a recent review I collaborated on with Dr. Phan Luu and internationally-acclaimed cognitive scientist Dr. Michael Posner), and should be of widespread interest to those studying cognition, emotion, motivation and motor control.

I have been involved in teaching on the local level (lectures and supervising graduate and medical students), national level (invited lectures), and international level (invited lectures and invited Chairman of Cognition & Emotion symposium at Human Brain Mapping).

I welcome your comments, questions and suggestions.

Research Support

We would like to give special thanks to the following organizations for their generous support of our research over the years:

National Institute of Mental Health (NIMH)
National Alliance for Research on Schizophrenia and Depression (NARSAD)
The Martinos Family
The Forrest C. Lattner Foundation
Eli Lilly & Company
The Mind-Body Medical Institute
NICHD
NLS
Scottish-Rite Schizophrenia Research Program
David Judah Research Fund
BT Research

Staff

George Bush, MD, MMSc
Laboratory Director
Assistant Director, Psychiatric Neuroimaging Research
Massachusetts General Hospital - East, CNY 9117
Building 149, 13th Street
Charlestown, MA 02129
Tel:617/724-6142, Fax:781/735-0554
Publications by Dr. Bush

Collaborators