Functional optical brain imaging: Toward noninvasive cognitive prosthetics

Abstract

When Licklider published Man-Computer Symbiosis in 1960, he stated that “It seems entirely possible that, in due course, electronic or chemical “machines” will outdo the human brain in most of the functions we now consider exclusively within its province. (p.2)” The brain-machine interface Licklider envisioned has been extended beyond his initial conceptions by noninvasive and portable technologies, such as EEG and near-infrared based optical brain imaging devices. These noninvasive neuroimaging tools facilitate better interfacing with the brain by providing the underlying principles that govern the brain's ability to adapt to and utilize new interface paradigms. Moreover, these enabling technologies can guide the development of prosthetics to compensate for cognitive deficits within impaired populations, as well as enhance cognitive performance for healthy populations. Functional near-infrared spectroscopy (fNIR), an emerging optical brain imaging system, will be introduced along with an illustration of its potential role in the development of cognitive prostheses. fNIR is a wearable neuroimaging device that enables the continuous, non-invasive, and portable monitoring of NIR light absorbance of oxygenated and deoxygenated hemoglobin in blood. Hemodynamics measured by fNIR is similar to functional MRI and provides information about ongoing brain activity. Drexel's Optical Brain Imaging Lab, comprised of an interdisciplinary team of engineers, cognitive and motor neuroscientists, and neurorehabilitation scientists have developed and integrated fNIR imaging techniques into an array of research paradigms to assess cognitive and motor activities of individuals with and without impairments. Applications of fNIR include cognitive workload and human performance assessments, credibility assessments, learning during performance of a gripping task with an electromyographically controlled exoskeleton gripper with haptic feedback, assessment of recovery from anesthesia, and brain-machine interface for communication and control. This talk will briefly address current developments of cognitive prostheses as well as the future direction of the field.