Abraham Z. Snyder, Ph.D., M.D.

Research Scientist
Radiology

Office Phone: 314-362-2012
FAX: 314-362-6110
Mailing Address:
Washington University School of Medicine
Department of Radiology, Campus Box 8225
4525 Scott Ave., Room 2121
St. Louis, MO 63110 USA

Email: avi@npg.wustl.edu


My work consists principally of applied image processing. Ongoing projects involve functional and structural magnetic resonance imaging (fMRI and MRI) as well as metabolic and receptor imaging using positron emission tomography (PET). This work requires development, maintenance and application of algorithms for image registration, image averaging, intensity inhomogeneity correction and image segmentation. Typical applications include correction for intra-acquisition head motion, coregistration of multi-spectral (including functional) datasets in the same individual, representation of functional responses on the smoothed or flattened cortical surface and generation of atlas representative target images for averaging over multiple individuals. Other applications include diffusion tensor imaging (DTI) and DTI-tractography.


Selected Publications:

Michelon P, Snyder AZ, Buckner RL, McAvoy M, Zacks JM. Neural correlates of incongruous visual information. An event-related fMRI study. Neuroimage. 2003 Aug;19(4):1612-26.

Astafiev SV, Shulman GL, Stanley CM, Snyder AZ, Van Essen DC, Corbetta M. Functional organization of human intraparietal and frontal cortex for attending, looking, and pointing. J Neurosci. 2003 Jun 1;23(11):4689-99.

Burgund ED, Kang HC, Kelly JE, Buckner RL, Snyder AZ, Petersen SE, Schlaggar BL. The feasibility of a common stereotactic space for children and adults in fMRI studies of development. Neuroimage. 2002 Sep;17(1):184-200.

McKinstry RC, Mathur A, Miller JH, Ozcan A, Snyder AZ, Schefft GL, Almli CR, Shiran SI, Conturo TE, Neil JJ. Radial organization of developing preterm human cerebral cortex revealed by non-invasive water diffusion anisotropy MRI. Cereb Cortex. 2002 Dec;12(12):1237-43.

Blasi V, Young AC, Tansy AP, Petersen SE, Snyder AZ, Corbetta M. Word retrieval learning modulates right frontal cortex in patients with left frontal damage. Neuron. 2002 Sep 26;36(1):159-70.

Barch DM, Csernansky JG, Conturo T, Snyder AZ. Working and long-term memory deficits in schizophrenia: is there a common prefrontal mechanism? J Abnorm Psychol. 2002 Aug;111(3):478-94.

Mintun MA, Vlassenko AG, Shulman GL, Snyder AZ. Time-related increase of oxygen utilization in continuously activated human visual cortex. Neuroimage. 2002 Jun;16(2):531-7.

Logan JM, Sanders AL, Snyder AZ, Morris JC, Buckner RL. Under-recruitment and nonselective recruitment: dissociable neural mechanisms associated with aging. Neuron. 2002 Feb 28;33(5):827-40.

Sheline YI, Mintun MA, Moerlein SM, Snyder AZ. Greater loss of 5-HT(2A) receptors in midlife than in late life. Am J Psychiatry. 2002 Mar;159(3):430-5.

Burton H, Snyder AZ, Conturo TE, Akbudak E, Ollinger JM, Raichle ME. Adaptive changes in early and late blind: a fMRI study of Braille reading. J Neurophysiol. 2002 Jan;87(1):589-607.

Sheline YI, Barch DM, Donnelly JM, Ollinger JM, Snyder AZ, Mintun MA. Increased amygdala response to masked emotional faces in depressed subjects resolves with antidepressant treatment: an fMRI study. Biol Psychiatry. 2001 Nov 1;50(9):651-8.

Simpson JR, Ongur D, Akbudak E, Conturo TE, Ollinger JM, Snyder AZ, Gusnard DA, Raichle ME. The emotional modulation of cognitive processing: an fMRI study. J Cogn Neurosci. 2000;12 Suppl 2:157-70.

Buckner RL, Snyder AZ, Sanders AL, Raichle ME, Morris JC. Functional brain imaging of young, nondemented, and demented older adults. J Cogn Neurosci. 2000;12 Suppl 2:24-34.

Black KJ, Snyder AZ, Koller JM, Gado MH, Perlmutter JS. Template images for nonhuman primate neuroimaging: 1. Baboon. Neuroimage. 2001 Sep;14(3):736-43.

Mintun MA, Lundstrom BN, Snyder AZ, Vlassenko AG, Shulman GL, Raichle ME. Blood flow and oxygen delivery to human brain during functional activity: theoretical modeling and experimental data.
Proc Natl Acad Sci U S A. 2001 Jun 5;98(12):6859-64. Epub 2001 May 29.

Zacks JM, Braver TS, Sheridan MA, Donaldson DI, Snyder AZ, Ollinger JM, Buckner RL, Raichle ME. Human brain activity time-locked to perceptual event boundaries. Nat Neurosci. 2001 Jun;4(6):651-5.

Raichle ME, MacLeod AM, Snyder AZ, Powers WJ, Gusnard DA, Shulman GL. A default mode of brain function. Proc Natl Acad Sci U S A. 2001 Jan 16;98(2):676-82.

Mukherjee P, Bahn MM, McKinstry RC, Shimony JS, Cull TS, Akbudak E, Snyder
AZ, Conturo TE. Differences between gray matter and white matter water diffusion in stroke: diffusion-tensor MR imaging in 12 patients. Radiology. 2000 Apr;215(1):211-20.

Rosen HJ, Petersen SE, Linenweber MR, Snyder AZ, White DA, Chapman L, Dromerick AW, Fiez JA, Corbetta MD. Neural correlates of recovery from aphasia after damage to left inferior
frontal cortex. Neurology. 2000 Dec 26;55(12):1883-94.

Burton H, Abend NS, MacLeod AM, Sinclair RJ, Snyder AZ, Raichle ME. Tactile attention tasks enhance activation in somatosensory regions of parietal cortex: a positron emission tomography study. Cereb Cortex. 1999 Oct-Nov;9(7):662-74.

Shulman GL, Ollinger JM, Akbudak E, Conturo TE, Snyder AZ, Petersen SE, Corbetta M. Areas involved in encoding and applying directional expectations to moving objects. J Neurosci. 1999 Nov 1;19(21):9480-96.

Shimony JS, McKinstry RC, Akbudak E, Aronovitz JA, Snyder AZ, Lori NF, Cull TS, Conturo TE. Quantitative diffusion-tensor anisotropy brain MR imaging: normative human data and anatomic analysis. Radiology. 1999 Sep;212(3):770-84.

Conturo TE, Lori NF, Cull TS, Akbudak E, Snyder AZ, Shimony JS, McKinstry RC, Burton H, Raichle ME. Tracking neuronal fiber pathways in the living human brain. Proc Natl Acad Sci U S A. 1999 Aug 31;96(18):10422-7.

Feiwell RJ, Black KJ, McGee-Minnich LA, Snyder AZ, MacLeod AM, Perlmutter JS. Diminished regional cerebral blood flow response to vibration in patients with blepharospasm. Neurology. 1999 Jan 15;52(2):291-7.

Corbetta M, Akbudak E, Conturo TE, Snyder AZ, Ollinger JM, Drury HA, Linenweber MR, Petersen SE, Raichle ME, Van Essen DC, Shulman GL. A common network of functional areas for attention and eye movements. Neuron. 1998 Oct;21(4):761-73.

Kelley WM, Miezin FM, McDermott KB, Buckner RL, Raichle ME, Cohen NJ, Ollinger JM, Akbudak E, Conturo TE, Snyder AZ, Petersen SE. Hemispheric specialization in human dorsal frontal cortex and medial temporal lobe for verbal and nonverbal memory encoding. Neuron. 1998 May;20(5):927-36.

Ojemann JG, Akbudak E, Snyder AZ, McKinstry RC, Raichle ME, Conturo TE. Anatomic localization and quantitative analysis of gradient refocused echo-planar fMRI susceptibility artifacts. Neuroimage. 1997 Oct;6(3):156-67.

Snyder AZ, Abdullaev YG, Posner MI, Raichle ME. Scalp electrical potentials reflect regional cerebral blood flow responses during processing of written words. Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1689-93.

Snyder AZ. Steady-state vibration evoked potentials: descriptions of technique and characterization of responses. Electroencephalogr Clin Neurophysiol. 1992 May-Jun;84(3):257-68.

Snyder AZ. Dipole source localization in the study of EP generators: a critique. Electroencephalogr Clin Neurophysiol. 1991 Jul-Aug;80(4):321-5.

Petersen SE, Fox PT, Snyder AZ, Raichle ME. Activation of extrastriate and frontal cortical areas by visual words and word-like stimuli. Science. 1990 Aug 31;249(4972):1041-4.

Curriculum Vitae (pdf)