Lawrence Snyder, MD, PhD
Washington University School of Medicine
Department of Ophthalmology and Visual Sciences
Campus Box 8096
660 S. Euclid Ave.
St. Louis, MO 63110
East McDonnell 313
My laboratory studes how the brain, and especially the cerebral cortex, combines sensory information with higher order cognition (rules, memory, etc.) in order to drive motor commands. Much of our work is focused on spatial processing for guiding eye and arm movements.
Parietal cortex provides an early link in the transformation of visual sensory information into motor commands. Patients with unilateral parietal damage may ignore objects in one half of the world. In severe cases, they may clothe only half of their body or eat from only half of their plate. Spatial memory is affected, and there are often motor deficits as well.
We record from individual neurons in the parietal cortex of macaque monkeys during complex tasks in order to understand the role of the cortex in the sensory-motor transformations. The animals are trained to look at and reach for colored spots of light, a monkey video game. We ask how the locations of these spots are represented by neural activity in the brain. What frame of reference is used? Is there a single, generic representation or multiple special purpose representations? How is spatial information from other sensory systems combined with visually-derived information? How is spatial information stored (memory)? How does the nature of the task, and what the animal intends to do, affect parietal processing? Is parietal cortex specifically involved in the learning of new sensory-motor mappings, or in coordinating eye and hand movement?
We perform our studies primarily in macaque monkeys, using single and multi-unit neuron recording, reversible inactivation of cortical areas, and MR-based tract tracing, functional MRI activation and functional MRI connectivity studies.
- Liu Y, Yttri EA, Snyder LH (2010 Apr). Intention and attention: different functional roles for LIPd and LIPv. Nat Neurosci. 13 (4): 495-500. Full Article
- Patel GH, Shulman GL, Baker JT, Akbudak E, Snyder AZ, Snyder LH, Corbetta M (2010 Mar 9). Topographic organization of macaque area LIP. Proc Natl Acad Sci U S A. 107 (10): 4728-33. Full Article
- Chang SW, Papadimitriou C, Snyder LH (2009 Dec 10). Using a compound gain field to compute a reach plan. Neuron. 64 (5): 744-55. Full Article
- Stoet G, Snyder LH (2009 May). Neural correlates of executive control functions in the monkey. Trends Cogn Sci. 13 (5): 228-34. Full Article
- Stoet G, Snyder LH (2007 Sep). Extensive practice does not eliminate human switch costs. Cogn Affect Behav Neurosci. 7 (3): 192-7. Full Article
- Vincent JL, Patel GH, Fox MD, Snyder AZ, Baker JT, Van Essen DC, Zempel JM, Snyder LH, Corbetta M, Raichle ME (2007 May 3). Intrinsic functional architecture in the anaesthetized monkey brain. Nature. 447 (7140): 83-6. Full Article