Steven E. Petersen, PhD
Dr. Petersen serves as Chief of the Neuropsychology Division.
We use behavioral and functional neuroimaging techniques to study the neural mechanisms underlying attention, language, learning and memory. Our current focus has been on aspects of experience-dependent change. In particular we are interested in neural substrates for episodic memory, procedural learning and recovery after brain injury. In episodic memory, our work has focused on areas related to episodic encoding. Many encoding tasks have been shown to activate regions in the dorsal frontal cortex These activations seem to be related to the kind of information encoded with left dorsal frontal regions active for verbal information (e.g., lists of words), and right frontal regions active for non-verbal information (e.g. unfamiliar faces). These relationships hold across many different stimulus types.
For studies of procedural learning, people are asked to trace through mazes, and they are imaged during early unskilled tracing, and after they become skilled at tracing the maze. Different areas of the brain are used for unskilled (right premotor and parietal cortex, left cerebellum) than skilled performance (SMA). This is consistent with ideas from behavioral literature that skilled and unskilled performance of a task are programmed at different levels of abstraction, and might use different neural substrates. In studies of language recovery following stroke in aphasic individuals, recruitment of areas not seen in normal subjects are found. These include apparently homologous regions in the opposite hemisphere, and "peri-lesional" activations on the ipsilateral side. Current investigations focus on the both the functional and prognostic value of the abnormal activations.
Dr. Petersen received his BA in Anthropology from the University of Montana in Missoula in 1974, and his PhD in Biology from the California Institute of Technology in 1982. He then moved the Bethesda, Maryland for a Postdoctural position at the National Eye Institute. His interest in studies on human neurobiology led him to move to Washington University Medical School in 1985.
Church, J.A., Fair, D.A., Dosenbach. N.U.F., Cohen, A.L., Miezin, F.M., Petersen, S.E., Schlaggar, B.L. (2009) Control networks in pediatric tourette syndrome show immature and anomalous patterns of functional connectivity. Brain, 132:225-238.
Dosenbach, N.U.F., Petersen, S.E. (2009) "Attentional Networks". In Squire, L.R. (ed.) Encyclopedia of Neuroscience Vol. 1, pp. 655-660.
Ihnen, S.K.Z., Church, J.A., Petersen, S.E., Schlaggar, B.L. (2009) Lack of generalizability of sex differences in the fMRI BOLD activity associated with language processing in adults. NeuroImage, 45(3):1020-1032.
Donaldson, D., Petersen S. Remember the source: dissociating frontal and parietal contributions to episodic memory. Epub, J of Cognitive Neuroscience.
White, B.R., Snyder, A.Z., Cohen, A.L., Petersen, S.E., Raichle, M.E., Schlaggar, B.L., Culver, J.P. (2009) Resting-state functional connectivity in the human brain revealed with diffuse optical tomography. NeuroImage, 47:148-56.
Fair, D.A., Cohen, A.L., Power, J.D., Dosenbach, N.U.F., Church, J.A., Miezin, F.M., Schlaggar, B.L., Petersen, S.E. (2009) Functional Brain Networks Develop from a "Local to Distributed" Organization. Epub, PLOS Computational Biology.
Fair, D.A., Choi, A.H., Dosenbach, Y.B., Coalson, R.S, Miezin, F.M., Petersen, S.E., Schlaggar, B.L. (2009) The functional organization of trial-related activity in lexical processing after early left hemispheric brain lesions: An event-related fMRI study. Accepted, Brain and Language.
Church, J.A., Wenger, K.K., Dosenbach, N.U.F., Miezin, F.M., Petersen, S.E., Schlaggar, B.L. (2009) Task control signals in pediatric Tourette syndrome show evidence of immature and anomalous functional activity. Accepted, Frontiers in Human Neuroscience.
© 2006-2012 Washington University School of Medicine