Regensburg 2007 – scientific programme
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BP: Fachverband Biologische Physik
BP 12: Neuroscience
BP 12.6: Talk
Tuesday, March 27, 2007, 12:00–12:15, H44
Non-invasive detection of human brain function using diffusing-wave spectroscopy — J. Li1, F. Jaillon1, G. Dietsche1, T. Elbert2, B. Rockstroh2, G. Maret1, and •T. Gisler1 — 1Universität Konstanz, Fachbereich Physik, 78457 Konstanz — 2Universität Konstanz, Fachbereich Psychologie, 78457 Konstanz
Near-infrared light which is multiply scattered by biological tissue contains rich information on microscopic motions of scatterers deep within the tissue. The analysis of the speckle pattern fluctuations in terms of microscopic particle displacements is the basis of diffusing-wave spectroscopy (DWS), the extension of quasi-elastic light scattering to the regime of strong multiple scattering.
DWS was recently used to detect the activation of the human motor cortex upon somatosensory stimulation through the intact scalp and skull [1, 2]. Analyzing the measured autocorrelation functions of the scattered electric field a significant, hemispherically asymmetric acceleration of the cortical dynamics upon stimulation was found.
The origin of this accelerated dynamics has not entirely been clarified. In this contribution we present DWS measurements with a multispeckle detection setup which allows to follow non-stationary scatterer dynamics upon different stimulation protocols (motor, visual, and memory) with a temporal resolution of 26ms and to discriminate scatterer dynamics related to pulsation from other mechanisms.
[1] T. Durduran et al., Opt. Lett. 29, 1766-1768 (2004). [2] J. Li et al., J. Biomed. Opt. 10, 044002-1-12 (2005).