ReviewThe use of near-infrared spectroscopy in the study of typical and atypical development

•We critically review the literature on both typical and atypical development using fNIRS.•We offer recommendations for future research, particularly in atypical populations.•We focus on how fNIRS in typical development may help identify atypical trajectories.

The use of functional near infrared spectroscopy (fNIRS) has grown exponentially over the past decade, particularly among investigators interested in early brain development. The use of this neuroimaging technique has begun to shed light on the development of a variety of sensory, perceptual, linguistic, and social-cognitive functions. Rather than cast a wide net, in this paper we first discuss typical development, focusing on joint attention, face processing, language, and sensorimotor development. We then turn our attention to infants and children whose development has been compromised or who are at risk for atypical development. We conclude our review by critiquing some of the methodological issues that have plagued the extant literature as well as offer suggestions for future research.