Don L. Jewett

Research Interests

Error detection of dipole/quadrupole analysis of evoked responses using FEA in SGI mini-supercomputer; New oscillatory brain waves related to Figure/Ground as affected by attention; New infant screening method using visual evoked responses;  Modeling very large pyramidal-cell network restrained by evoked-response data; Software for Scientific Compendia.

Research Summary

1. Finite-Element Analysis of intra-cranial current-flows and surface potentials in headshape models derived from MRI.  We are using error-analysis to permit detection of the best model parameters for accurate localization of neuronal dipoles and quadrupoles in the CNS.  The study involves EEG/MEG/MRI data from each subject, where the EEG data are visual evoked responses that can be localized to V1.  We have a 12-CPU SGI Itanium2 mini-supercomputer running Linux (equal to about 50 PCs).
Every byte of the 44 GB of RAM is accessible to every CPU.

2. A-waves are totally-new evoked responses in humans that reveal differences in brain processing of Figure compared with Ground.  Analysis of A-waves in relation to spontaneous Alpha to determine whether the cell groups overlap.  We will develop the means to detect the activity of inter-heminspheric neurons in the corpus callosum, and the thalamocortical radiation.  The effects of attention will be studied.

3. A new infant screening test will be developed based upon the work in #2  (with eyes closed, asleep).  

4. Modeling of very-large pyramidal cell networks constrained by the findings of #2 will be done, using the SGI computer.  These will have 10-100 times the number of neurons compared to published work.

5. Software for Scientific Compendia using both Multi-Level presentations, and Reverse-Citations will be developed. 

Selected Publications

Related to A-waves in humans:

D.L. Jewett, T. Hart, L.J. Larson-Prior, B. Baird, M. Olson, M. Trumpis, K. Makayed, P. Bavafa. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects. BMC Neuroscience 7:18, 2006.

D.L. Jewett, G. Caplovitz, B. Baird, M. Trumpis, M. Olson, L.J. Larson-Prior. The use of QSD (q-sequence deconvolution) to recover superposed, transient evoked-responses. Clin Neurophysiol. 115:2754-2775, 2004.  See: http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15546784

Related to Errors in Dipole modeling:

D.J. Fletcher, A. Amir, D.L. Jewett, G. Fein. improved method for computation of potentials in a realistic head shape
model. IEEE Trans. Biomed Eng., 42(11): 1094-1104, 1995

D.L. Jewett, Z. Zhang: Multiple-generator erfrors are unavoidable under model misspecification. EEG clin Neurophysiol 95:135-142, 1995

Z. Zhang, D.L. Jewett, G. Goodwill.  Insidious errors in dipole parameters due to shell model misspecification using
multiple time-points. Brain topography, 6(4):283-297, 1994

Related to Scientific Compendia:

D.L. Jewett. Scientific or Medical Multi-Level Compendia with Context-Containing Cytation-Lists. See: http://www.abratech.com/MultiLevelSciC.html


D. L. Jewett.  Multi-level Writing in Theory and Practice Visible Language 15:32-40, 1981.    See:  http://repositories.cdlib.org/postprints/1547/