Stanley Klein

Research Interests

Brain source localization using a evoked potentials, MEG and fMRI. Nonlinear analysis of neural responses. Vision & image processing. Refractive surgery.

Research Summary

1) Localizing sources of brain activity. We have developed a new method for merging the exquisite spatial localization of fMRI with the exquisite temporal localization of evoked potentials. Our novel approach to evoked potentials is to combine multiple electrodes (128 lately) with multiple simultaneous stimuli (60 lately and we are planning for more). In collaboration with Los Alamos we are engaged in obtaining multichannel magnetic encephalography (MEG) data. We are the first group to combine multiple channels on the head and multiple stimuli together with software that takes advantage of the cortical representation of the visual world. On the fMRI side we are developing methods for improving the fine grained localization of the fMRI signal. We are developing software for doing experiments on the new powerful Berkeley MRI/fMRI system. We are funded by NIH and Los Alamos (a collaborative UC-Los Alamos grant) to improve these methodologies.

2) Improving refractive surgery. Refractive surgery has grown dramatically in the past two years. More than a million Americans have had their corneas reshaped to avoid wearing glasses or contact lenses. Although the procedure has greatly improved over the past few years, there are still severe problems with night vision. We have a number of ideas on how to have are developed new methods for measuring corneal shape before and after refractive surgery. These methods allow us to measure larger regions of the cornea than was feasible previously. We are also devising methods for improved testing of the patients to pick up losses that were previously missed. Finally in collaboration with Prof. Barsky of computer science and bioengineering we are developing new techniques for designing and fitting contact lenses. We are planning to use MEMS adaptive optics techniques for improved visual optics. We have NIH funds for carrying out this research.

Selected Publications

Slotnick, S.D., Klein, S.A., Carney, T., Sutter, E.E. & Dastmalchi, S. (1999). Using multi-stimulus VEP source localization to obtain a retinotopic map of human primary visual cortex. Clinical Neurophysiology. 110, 1793-1800.

Klein, S.A. & Garcia, D.D. (2000). Line of Sight and Alternative Representations of Aberrations of the Eye. J. Refractive Surgery. 16 630-635.

Slotnick, S.D., Klein, S.A., Carney, T. & Sutter, E. (2001) A direct method for estimating the visual space scaling factor of the human visual cortex. In Press Clinical Neurophysiology