At every waking moment the human brain absorbs information, selectively filters it, and integrates it into perceptions and memories to achieve goals. These processes rely on the unique functions of individual regions of the brain, as well as on coordinated activity across regions organized into large-scale networks. How these multi-scale processes are coordinated remains an enigma. My lab studies how human brain networks are organized and how they contribute to the multitude of goal-directed behaviors humans can complete. Furthermore, we examine how these processes break down with damage and disease. The lab addresses questions through three interrelated lines of research on (1) large-scale networks and hubs, (2) the role of top-down control systems, and (3) top-down modulation of visual processing.
To answer these questions, we aim to use a multifaceted approach with complementary methods to (i) track the spatial and dynamic characteristics of brain activity (via functional magnetic resonance imaging [fMRI] and electroencephalography [EEG]), and (ii) manipulate and quantify perturbation of brain systems (via transcranial magnetic stimulation [TMS], recordings from neurological patients, and pharmacological manipulations). We pair these methods with sophisticated analysis techniques to provide a quantitative description of brain function, using functional connectivity and graph theoretical measures to characterize brain networks, and encoding models to characterize functional selectivity within brain regions. This broad toolkit enables us to address novel systems-level questions about the organization of human brain networks, their role in top-down control, and how they break down with damage.
Gratton, C., Koller, JM, Shannon, W, Greene, DJ, Snyder, AZ, Petersen, SE, Perlmutter, JS, Campbell, MC. (2018). Emergent functional network effects in Parkinson disease. Cerebral Cortex.
Gratton, C., Laumann, TO, Nielsen, AN, Greene, DJ, Gordon, EM, Gilmore, AW, Nelson, SM, Coalson, RS, Snyder, AZ, Schlaggar, BL, Dosenbach, NUF, Petersen, SE (2018). Functional brain networks are dominated by stable group and individual factors, not cognitive or daily variation. Neuron, 98(2) 439-452.
Gratton, C., Yousef, S., Aarts, E., Wallace, D. L., D'Esposito, M., Silver, M. (2017). Cholinergic, But Not Dopaminergic or Noradrenergic, Enhancement Sharpens Visual Spatial Perception in Humans. The Journal of Neuroscience, 37(16): 4405-4415.
Gratton, C., Neta, M., Sun, H., Ploran, E. J., Schlaggar, B. L., Wheeler, M. E., Petersen, S. E., Nelson, S. M. (2016). Distinct Stages of Moment-to-Moment Processing in the Cinguloopercular and Frontoparietal Networks. Cerebral Cortex, 1-15.
Gratton, C., Laumann, T. O., Gordon, E. M., Adeyemo, B., Petersen, S. E. (2016). Evidence for Two Independent Factors that Modify Brain Networks to Meet Task Goals. Cell Reports, 17: 1276-1288.
Gratton, C., Sreenivasan, K. K., Silver, M. A., D'Esposito, M. (2013). Attention Selectively Modifies the Representation of Individual Faces in the Human Brain. The Journal of Neuroscience, 33(16): 6979-6989.
Gratton, C., Nomura, E. M., Pérez, F., D'Esposito, M. (2012). Focal Brain Lesions to Critical Locations Cause Widespread Disruption of the Modular Organization of the Brain. Journal of Cognitive Neuroscience, 24(6): 1275-1285.