Noninvasive optical evaluation of low frequency oscillations in prefrontal cortex hemodynamics during verbal working memory

Ting Li; Yue Zhao; Kai Li; Yunlong Sun

doi:10.1117/12.2041873

Translator Disclaimer

20 March 2014 Noninvasive optical evaluation of low frequency oscillations in prefrontal cortex hemodynamics during verbal working memory

Ting Li, Yue Zhao, Kai Li, Yunlong Sun

Author Affiliations +

Proceedings Volume 8928, Optical Techniques in Neurosurgery, Neurophotonics, and Optogenetics; 89280Q (2014) https://doi.org/10.1117/12.2041873
Event: SPIE BiOS, 2014, San Francisco, California, United States

Abstract

The low frequency oscillation (LFO) around 0.1 Hz has been observed recently in cerebral hemodynamic signals during rest/sleep, enhanced breathing, and head- up-tilting, showing that cerebral autoregulation can be accessed by LFOs. However, many brain function researches require direct measurement of LFOs during specified brain function activities. This pilot study explored using near-infrared spectroscopy/imaging (NIRS) to noninvasively and simultaneously detect LFOs of prefrontal cerebral hemodynamics (i.e., oxygenated/deoxygenated/total hemoglobin concentration: △[oxy-Hb]/ △[deoxy-Hb]/ △[tot-Hb]) during N-back visual verbal working memory task. The LFOs were extracted from the measured variables using power spectral analysis. We found the brain activation sites struck clear LFOs while other sites did not. The LFO of △[deoxy-Hb] acted as a negative pike and ranged in (0.05, 0.1) Hz, while LFOs of △[oxy-Hb] and △[tot-Hb] acted as a positive pike and ranged in (0.1, 0.15) Hz. The amplitude difference and frequency lag between △[deoxy-Hb] and △[oxy-Hb]/ △[tot-Hb] produced a more focused and sensitive activation map compare to hemodynamic amplitude-quantified activation maps. This study observed LFOs in brain activities and showed strong potential of LFOs in accessing brain functions.

Citation Download Citation

Ting Li, Yue Zhao, Kai Li, and Yunlong Sun "Noninvasive optical evaluation of low frequency oscillations in prefrontal cortex hemodynamics during verbal working memory", Proc. SPIE 8928, Optical Techniques in Neurosurgery, Neurophotonics, and Optogenetics, 89280Q (20 March 2014); https://doi.org/10.1117/12.2041873

ACCESS THE FULL ARTICLE