Schizophrenia spectrum disorders are debilitating conditions which cause adverse consequences for people with the disorder, their relatives, and general society. Impairments in social cognition, especially in emotion processing, have been found to be a primary determinant of poor community functioning. Cognitive remediation can reduce social cognitive dysfunction when it is provided early in illness progression and individually tailored. Nonetheless, current diagnostic methods for schizophrenia spectrum disorders, such as clinical interviews, are not entirely reliable, can be impractical, and often depend upon the progression of symptoms to ensure accuracy. Functional near-infrared spectroscopy (fNIRS) is an emerging neuroimaging technique that may be applied to identify biomarkers of emotion processing impairment in the early stages of schizophrenia. fNIRS overcomes many limitations of current assessment methods, is practically advantageous compared to alternative neuroimaging techniques, and is well suited for measuring parts of the prefrontal cortex (PFC), a region established in the cognitive processing of emotion. Nonetheless, before fNIRS can be considered for use in practice, its capacity to reliably detect activation during emotion processing and distinguish between high and low schizotypy needs to be evaluated. This thesis aims to determine the capacity of fNIRS for detecting prefrontal activation during emotion processing and identify differences in activation between people with high and low schizotypy.