Optical Imaging Approaches in Cognitive Neuroscience

Abstract

Cognitive neuroscience is a science of information processing. Optical imaging approaches play more and more important roles in revealing the mechanisms of information processing at different levels of the nervous system. This paper introduces optical imaging approaches pursued in cognitive neuroscience at three levels at the Key Laboratory of Biomedical Photonics of the Ministry of Education of China. At the molecular and cellular level, advances in microscopy, molecular optical markers, and sample preparations have made it possible to characterize the form and function of neurons in unprecedented detail. The development of two-photon excitation has enabled fluorescent imaging of small structures amidst highly scattering media with little photodamage. The combination of multi-photon excitation and a multi-electrode array provides a powerful approach for imaging neuronal networks. Intrinsic signal imaging (ISI) and laser speckle imaging (LSI) are effective for imaging intrinsic signals at a given cortical site. No other imaging technique for the visualization of functional organization in the living brain provides comparable spatial resolution. It is this level of resolution that reveals where proces sing is performed-a necessary step for understanding the neural cod e at the population level. Completely noninvasive optical imaging through the intact human skull, such as functional near infrared imaging, may provide an imaging tool with the spatial and temporal resolutions to expand our knowledge of the principles underlying the remarkable performance of the human cerebral cortex.