Stephen Engel Professor S253 Elliott, (612) 625-5571 engel@umn.edu Education Ph.D., 1995, Stanford University

Statement of Interests

The simple acts of recognizing a friend's face, or noticing the color of their hair, require an enormous amount of work by our brains. My lab focuses on understanding this work. We use the methods of cognitive neuroscience to characterize precisely how neurons in the human brain support visual perception. Most of our experiments combine behavioral measurements of perception with functional MRI measurements of neural activity and, when possible, mathematical modeling.

One main topic under investigation is perceptual learning. With training, the adult human visual system can improve dramatically in almost any task. Radiologists, for example, can see patterns in x-ray images that are invisible to the untrained eye. One current study in the lab is investigating the changes in the brain that underlie this expertise. Other studies examine training on simpler tasks, such as detecting the presence of a very faint line on an otherwise blank screen. Training these simple tasks has allowed us to measure changes in some of the earliest stages of vision in the cortex, regions that were once viewed as lacking plasticity in the adult. Other general topics under study in the lab include color perception, surface perception, visual awareness, and (in collaboration) human memory.

One goal of the lab has been to develop cutting edge tools for use in studying human vision. To this end, we helped pioneer functional MR imaging of human visual cortex, and we continue to expand its use. We are currently pushing the temporal limits of the method to measure the timing of cognitive processes with accuracy at or below 100 msec. We are also developing novel "altered reality" technology, that allows users to see in a world that is just like ours, but that differs in a controlled way. We plan to study, for example, how the visual system adapts when we remove (or enhance) all vertical lines from what subjects see.

Selected Publications

Bouvier, S. E., & Engel, S. A. (2006). Behavioral Deficits and Cortical Damage Loci in Cerebral Achromatopsia. Cerebral Cortex, 16, 183-91.

Engel, S. A. (2005). Adaptation of oriented and unoriented color-selective neurons in human visual areas. Neuron, 45, 613-23.

Furmanski, C. S., Schluppeck, D., & Engel, S. A. (2004). Learning Strengthens the Response of Primary Visual Cortex to Simple Patterns. Current Biology, 14, 573-578.

Zeineh, M. M., Engel, S. A., Thompson, P. M., & Bookheimer, S. Y. (2003). Dynamics of the hippocampus during encoding and retrieval of face-name pairs. Science, 299, 577-580.

Tong, F. H., & Engel, S. A. (2001). Interocular rivalry revealed in the human cortical blind-spot representation. Nature, 411, 195-199.

Eldridge, L. L., Knowlton, B. J., Furmanski, C. S., Bookheimer, S. Y., & Engel, S. A. (2000). Remembering eposides: a selective role for the hippocampus during retrieval. Nature Neuroscience, 3, 1149-1152.