Neuroergonomics is the study of the behavior of the human brain. Its theories and principles are based on ergonomics, neuroscience, and the extant literature on human beings. Neuroimaging studies use neuroimaging techniques to understand the structures, mechanisms, and functions of the brain. Neuroimaging techniques are divided into two general categories: direct displays of neuronal activity in response to stimuli, such as electroencephalography (EEG) and positron emission tomography-computed tomography (PET-CT), and indirect metabolic indicators of neuronal activity, such as functional magnetic resonance imaging (fMRG), functional near-infrared spectroscopy (fNIRS), and functional transcranial Doppler sonography (fTCD). This review outlines the techniques and current applications of neuroergonomic methods used in mental workload and vigilance.